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Sample records for bolting requirements based

  1. Evaluation of Roof Bolting Requirements Based on In-Mine Roof Bolter Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Syd S. Peng

    2005-10-01

    Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on this information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. For the prediction of roof geology and stability condition in real time, a micro processor was used and a program developed to monitor and record the drilling parameters of roof bolter. These parameters include feed pressure, feed flow (penetration rate), rotation pressure, rotation rate, vacuum pressure, oil temperature of hydraulic circuit, and signals for controlling machine. From the results of a series of laboratory and underground tests so far, feed pressure is found to be a good indicator for identifying the voids/fractures and estimating the roof rock strength. The method for determining quantitatively the location and the size of void/fracture and estimating the roof rock strength from the drilling parameters of roof bolter was developed. Also, a set of computational rules has been developed for in-mine roof using measured roof drilling parameters and implemented in MRGIS (Mine Roof Geology Information System), a software package developed to allow mine engineers to make use of the large amount of roof drilling parameters for predicting roof geology properties automatically. For the development of roof bolting criteria, finite element models were developed for tensioned and fully grouted bolting

  2. A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring.

    Science.gov (United States)

    Wu, Jian; Cui, Xingmei; Xu, Yunpeng

    2016-01-01

    In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag's antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt's information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system) provided valuable information regarding the strengths and weaknesses of the proposed system. PMID:26828498

  3. Stress analysis of closure bolts for shipping casks

    International Nuclear Information System (INIS)

    This report specifies the requirements and criteria for stress analysis of closure bolts for shipping casks containing nuclear spent fuels or high level radioactive materials. The specification is based on existing information conceming the structural behavior, analysis, and design of bolted joints. The approach taken was to extend the ASME Boiler and Pressure Vessel Code requirements and criteria for bolting analysis of nuclear piping and pressure vessels to include the appropriate design and load characteristics of the shipping cask. The characteristics considered are large, flat, closure lids with metal-to-metal contact within the bolted joint; significant temperature and impact loads; and possible prying and bending effects. Specific formulas and procedures developed apply to the bolt stress analysis of a circular, flat, bolted closure. The report also includes critical load cases and desirable design practices for the bolted closure, an in-depth review of the structural behavior of bolted joints, and a comprehensive bibliography of current information on bolted joints

  4. A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring

    Science.gov (United States)

    Wu, Jian; Cui, Xingmei; Xu, Yunpeng

    2016-01-01

    In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag’s antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt’s information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system) provided valuable information regarding the strengths and weaknesses of the proposed system. PMID:26828498

  5. A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring

    Directory of Open Access Journals (Sweden)

    Jian Wu

    2016-01-01

    Full Text Available In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag’s antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt’s information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system provided valuable information regarding the strengths and weaknesses of the proposed system.

  6. Research on Torque Loading Technology Based on L Lever in Spacecraft Bolt

    Directory of Open Access Journals (Sweden)

    Song Xiaohui

    2015-01-01

    Full Text Available As the main form of structure assembly, the stability of bolt joint is directly related to the performance of spacecraft. This essay is used to analyze the cause of standard torque spanner which is not suitable to the tightening torque and summarized according to different operating conditions. Based on thorough analysis of fastening principles and principle of type serialization, a scheme of integrated L Lever is established. The results of experimentation indicate that the scheme of integrated L Lever is reasonable along with the requirement of developing long-life and high-reliability spacecraft. Therefore, the stability of fasteners is greatly enhanced.

  7. Estimation of maximum axial force of anchor bolts in consideration of random bolt failures

    International Nuclear Information System (INIS)

    This paper proposes a method for structural reliability analysis of anchor bolts used in the support skirt of a reactor vessel. The method is based on the conservative assumption that a few anchor bolts within the skirt's inner-wall may fail in a random nature. Under the assumption, the maximum axial forces in the intact bolts are estimated. To reflect the uncertainty, random numbers are generated to simulate the possible failed bolts among a total of 60 bolts, which are circumferentially arranged along the inner side of the wall. Then the outcome of failed bolts together with their locations for every 60 bolts is defined as an experiment of a sample. The locations of failed bolt can significantly affect the stress analysis and its random outcomes require an efficient calculation scheme. In this paper we propose a rapid calculation algorithm, thus the direction of bending moment that causes the worst scenario in the stress analysis of bolts for each experiment can be rapidly found. Taking into consideration of design loads, the finite element method is further employed to calculate the maximum axial bolt force of each experiment. After statistical analysis of maximum axial forces from all experiments, the average maximum axial-force interval that the remaining bolts can withstand under a given random condition is estimated with a 95% confidence level. This interval can be used in conjunction with various results of structural integrity assessment to ensure the structural safety and reliability of a nuclear power plant component

  8. Revised, low cost ultrasonic sealing bolts for use in nuclear applications, sealing bolts based on transponder technology suitable also for non nuclear applications

    Energy Technology Data Exchange (ETDEWEB)

    Sironi, Marco; Poucet, Andre; Tebaldi, Piercarlo; Selvagio, Gianfranco [European Commission, Ispra (Italy). Inst. for the Protection and Security of the Citizen; Trojano, Luca [Univ. di Genova (Italy). Facolta di Ingegneria

    2003-05-01

    A revised design of sealing bolt based on ultrasonic techniques has been developed at SILab. The bolt design has been strongly simplified, also the reading head has been redesigned with the aim of reducing costs and weights. A special low cost box is used to interface the dedicated ultrasonic board allowing the use of a standard portable computer for reading and data acquisition. The new system is fully compatible with the old one. An innovative design of sealing clamp has been also developed at SILab. The system, based on multi-transponder technology, is able to fulfill the following functions: - To confirm its correct installation, - To detect an illegal opening, - To store information in a permanent memory, inside the seal, when required, - To have a good mechanical strength to prevent illegal opening, - To have a unique identification of the seal. All the readings/writings can be done automatically through a proper antenna and stored in a database that can be made available on line and will give, in real time, information about the correct installation, the integrity of the seal and all the readings done in each check point. A typical application could be on containers to detect illegal opening and to follow the travel of the shipping from shipment to the final delivery. Also innovative remote positioning tools are under development.

  9. Revised, low cost ultrasonic sealing bolts for use in nuclear applications, sealing bolts based on transponder technology suitable also for non nuclear applications

    International Nuclear Information System (INIS)

    A revised design of sealing bolt based on ultrasonic techniques has been developed at SILab. The bolt design has been strongly simplified, also the reading head has been redesigned with the aim of reducing costs and weights. A special low cost box is used to interface the dedicated ultrasonic board allowing the use of a standard portable computer for reading and data acquisition. The new system is fully compatible with the old one. An innovative design of sealing clamp has been also developed at SILab. The system, based on multi-transponder technology, is able to fulfill the following functions: - To confirm its correct installation, - To detect an illegal opening, - To store information in a permanent memory, inside the seal, when required, - To have a good mechanical strength to prevent illegal opening, - To have a unique identification of the seal. All the readings/writings can be done automatically through a proper antenna and stored in a database that can be made available on line and will give, in real time, information about the correct installation, the integrity of the seal and all the readings done in each check point. A typical application could be on containers to detect illegal opening and to follow the travel of the shipping from shipment to the final delivery. Also innovative remote positioning tools are under development

  10. Barrel Bolt Cracking in a German PWR

    Energy Technology Data Exchange (ETDEWEB)

    Kilian, R.; Maussner, G. [AREVA GmbH (Germany); Koenig, G. [EnBW Kernkraft GmbH (Germany)

    2011-07-01

    In this paper, the results of failure analysis of cracked barrel bolts will be shown. The barrel bolts are made of German material number 1.4571 corresponding to 316 Ti. To ensure that the required mechanical properties are achieved, the material used was cold worked. At the end of the eighties, the bolts were installed to replace Inconel X- 750 bolts. The design used is a 'star bolt'. In 2005, cracking was first observed. In this report, the results of destructive examinations showing intergranular stress corrosion cracking will be presented. M16-Bolts exhibited cracking only in the area of cup, preventing unintentional loosening. All selected and examined M12-Bolts showed similar crack initiation in the head. Cracks may initiate on transition radii between the head and shank. The shank and thread of all bolts (M12 and M16) exhibited no indications of cracking. Bolts that experienced cracking could be clearly identified through visual inspection. The ultrasonic testing technique applied confirmed crack locations in the head. All cracks were attributed to Intergranular Stress Corrosion Cracking (IGSCC). Fracture surfaces exhibited relatively thin, dark layers and, in addition to corrosion products of the base metal, the debris on the shank and head also contained traces of Al, Si, Cu and Zn. (authors)

  11. Bolting applications

    Energy Technology Data Exchange (ETDEWEB)

    Czajkowski, C J

    1984-05-01

    An investigation of bolting practices specific to the nuclear industry was performed. The report covered a large spectrum of topics e.g. bolts embedded in concrete, specifications, inspection of bolting, both at receipt and inservice. Plots of preload versus yield strength for different bolting materials in different environments are presented as well as information relative to the stress corrosion cracking resistance of the more recent reactor internals bolting materials A286 and Inconel X-750. Part of the report contains input by Standard Pressed Steel Inc. (a bolting consultant) relative to bolting standards, cottering methods and potential areas for bolting improvement.

  12. Structural Integrity Assessment of High-Strength Anchor Bolt in Nuclear Power Plant based on Fracture Mechanics Concept

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Eunmo; Huh, Namsu [Seoul Nat' l Univ. of Science and Technology, Seoul (Korea, Republic of); Shim, Heejin; Oh, Changkyun; Kim, Hyunsu [KEPCO Engineering and Construction Company, Inc., Yongin (Korea, Republic of)

    2013-07-15

    The failure of a bolted joint owing to stress corrosion cracking (Succ) has been considered one of the most important structural integrity issues in a nuclear power plant. In this study, the failure possibility of bolting, which is used to support the steam generator of a pressurized water reactor, owing to Succ and brittle fracture was evaluated in accordance with guidelines proposed by the Electric Power Research Institute, which are called the Reference Flaw Factor method. For this evaluation, first, detailed finite element stress analyses were conducted to obtain the actual nominal stresses of bolting in which either service loads or bolt preload were considered. Based on these nominal stresses, the structural integrity of bolting was addressed from the viewpoints of Succ and toughness. In addition, the accuracy of the EPRI Reference Flaw Factor for assessing bolting failure was investigated using finite element fracture mechanics analyses.

  13. A Component-Based Study of the Effect of Diameter on Bond and Anchorage Characteristics of Blind-Bolted Connections.

    Directory of Open Access Journals (Sweden)

    Muhammad Nasir Amin

    Full Text Available Structural hollow sections are gaining worldwide importance due to their structural and architectural advantages over open steel sections. The only obstacle to their use is their connection with other structural members. To overcome the obstacle of tightening the bolt from one side has given birth to the concept of blind bolts. Blind bolts, being the practical solution to the connection hindrance for the use of hollow and concrete filled hollow sections play a vital role. Flowdrill, the Huck High Strength Blind Bolt and the Lindapter Hollobolt are the well-known commercially available blind bolts. Although the development of blind bolts has largely resolved this issue, the use of structural hollow sections remains limited to shear resistance. Therefore, a new modified version of the blind bolt, known as the "Extended Hollo-Bolt" (EHB due to its enhanced capacity for bonding with concrete, can overcome the issue of low moment resistance capacity associated with blind-bolted connections. The load transfer mechanism of this recently developed blind bolt remains unclear, however. This study uses a parametric approach to characterising the EHB, using diameter as the variable parameter. Stiffness and load-carrying capacity were evaluated at two different bolt sizes. To investigate the load transfer mechanism, a component-based study of the bond and anchorage characteristics was performed by breaking down the EHB into its components. The results of the study provide insight into the load transfer mechanism of the blind bolt in question. The proposed component-based model was validated by a spring model, through which the stiffness of the EHB was compared to that of its components combined. The combined stiffness of the components was found to be roughly equivalent to that of the EHB as a whole, validating the use of this component-based approach.

  14. Linkage Map Construction and Quantitative Trait Loci Analysis for Bolting Based on a Double Haploid Population of Brassica rapa

    Institute of Scientific and Technical Information of China (English)

    Xu Yang; Yang-Jun Yu; Feng-Lan Zhang; Zhi-Rong Zou; Xiu-Yun Zhao; De-Shuang Zhang; Jia-Bing Xu

    2007-01-01

    Early bolting of Chinese cabbage (Brassica rapa L.) during spring cultivation often has detrimental effects on the yield and quality of the harvested products. Breeding late bolting varieties is a major objective of Chinese cabbage breeding programs. in order to analyze the genetic basis of bolting traits, a genetic map of B. rapa was constructed based on amplified fragment-length polymorphism (AFLP), sequence-related amplified polymorphism (SRAP), simple sequence repeat (SSR), random amplification of polymorphic DNA (RAPD), and isozyme markers. Marker analysis was carried out on 81 double haploid (DH) lines obtained by mlcrospore culture from F1 progeny of two homozygous parents: B. rapa L. ssp. pekinensis (BY) (an extra-early bolting Chinese cabbage line) and B. rapa L. ssp. rapifera (MM) (an extra-late bolting European turnip line). A total of 326 markers including 130 AFLPs, 123 SRAPs, 16 SSRs, 43RAPDs and 14 isozymes were used to construct a linkage map with 10 linkage groups covering 882 cM with an average distance of 2.71 cM between loci. The bolting trait of each DH line was evaluated by the bolting index under controlled conditions. Quantitative trait loci (QTL) analysis was conducted using multiple QTL model mapping with MapQTL5.0 software. Eight QTLs controlling bolting resistance were identified. These QTLs, accounting for 14.1% to 25.2% of the phenotyplc variation with positive additive effects, were distributed into three linkage groups. These results provide useful information for molecular marker-assisted selection of late bolting traits in Chinese cabbage breeding programs.

  15. Remote Impedance-based Loose Bolt Inspection Using a Radio-Frequency Active Sensing Node

    International Nuclear Information System (INIS)

    This paper introduces an active sensing node using radio-frequency (RF) telemetry. This device has brought the traditional impedance-based structural health monitoring (SHM) technique to a new paradigm. The RF active sensing node consists of a miniaturized impedance measuring device (AD5933), a microcontroller (ATmega128L), and a radio frequency (RF) transmitter (XBee). A macro-fiber composite (MFC) patch interrogates a host structure by using a self-sensing technique of the miniaturized impedance measuring device. All the process including structural interrogation, data acquisition, signal processing, and damage diagnostic is being performed at the sensor location by the microcontroller. The RF transmitter is used to communicate the current status of the host structure. The feasibility of the proposed SHM strategy is verified through an experimental study inspecting loose bolts in a bolt-jointed aluminum structure

  16. A novel approach to predict the pin load distribution of multiple bolt-jointed composite laminate based on the circuit model

    Science.gov (United States)

    Yang, Xiankun; Chen, Haoyuan; Cheng, Linan; Zheng, Xitao

    2012-04-01

    The circuit model was applied to predict the pin load distribution of composite multiple bolt-joint structure. The load, flexibility and deformation of the mechanics model were equivalent to the current, resistance and voltage of the circuit model, respectively. Based on the above assumption, it could be found that the Hooke's law and the deformation compatibility equation in the origin mechanics model transformed into the Ohm's law and the voltage balance equation in the new circuit model. This approach translated the complex model of composite multiple bolt-jointed into a simple circuit model which consisted of some series circuits and parallel circuits. The analysis of the new circuit model had formed n-1 independence voltage balance equations and a current balance equation, thus, the current and load of each bolt could be calculated. In the new model, power sources which were added as required in some branch circuits could also simulate the clearance or interference in the origin model. Compared with the result of the multiple bolt-joints composite laminate test, the new approach could make an excellent performance to estimate the load distribution.

  17. Comparative study of bolt spacing formulas used in bolted joint designs

    International Nuclear Information System (INIS)

    Bolted flange joints are the most popular type of connection between pressure vessels and piping equipment. They are very attractive type of connection because they are simple to mount and offer the possibility of disassembly. However, they are very complex structures to design and analyze and often result in leakage failure. One of the raisons is the loss of tightness that results from the uneven distribution of the gasket contact stresses in the radial and circumferential direction. Many factors contribute to such a failure; bolt load non-uniformity, inadequate flange to gasket stiffness, inappropriate bolt spacing requirements or a combinations of some of these. The variation of the contact stress in the circumferential direction between any two bolts is dictated by bolt spacing. This paper is an extension of the work in which the more accurate analytical solution based on the theory of circular beams resting on a linear elastic foundation is used to validate some existing flange bolt spacing formulas and in particular the TEMA formula, Robert's formula and the one recently developed by Koves. The relationship between bolt spacing and the gasket compression modulus, flange thickness and size is deduced from an analysis that considers a maximum tolerated gasket contact stress difference obtained at the bolt and between two bolts. Comparison between these different methods is also provided. - Highlights: • Gasket stress is estimated using theory of circular beams on linear elastic foundation. • TEMA, Robert's and Koves' formulas are compared against the developed model. • A recommendation is made to use Koves' formula for design. • Use a correction factor of 1/(1-ν2) to accommodate small diameter flanges

  18. New bolting structure of fractured roof based on the Bossinesq equations

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Present support theories contain a number of shortcomings in the designation of fractured roof bolt parameters of rectangular or trapezoidal coal roadways.Roof fall accidents occur easily in this kind of roadway.Based on the Bossinesq equations and the Mohr strength theory,we propose a theory of an anchored cluster structure for fractured roofs and have investigated the formation of such an anchored cluster structure,its self stability mechanism and mechanical properties.The results show that an anchor and ...

  19. Decision Fusion System for Bolted Joint Monitoring

    Directory of Open Access Journals (Sweden)

    Dong Liang

    2015-01-01

    Full Text Available Bolted joint is widely used in mechanical and architectural structures, such as machine tools, industrial robots, transport machines, power plants, aviation stiffened plate, bridges, and steel towers. The bolt loosening induced by flight load and environment factor can cause joint failure leading to a disastrous accident. Hence, structural health monitoring is critical for the bolted joint detection. In order to realize a real-time and convenient monitoring and satisfy the requirement of advanced maintenance of the structure, this paper proposes an intelligent bolted joint failure monitoring approach using a developed decision fusion system integrated with Lamb wave propagation based actuator-sensor monitoring method. Firstly, the basic knowledge of decision fusion and classifier selection techniques is briefly introduced. Then, a developed decision fusion system is presented. Finally, three fusion algorithms, which consist of majority voting, Bayesian belief, and multiagent method, are adopted for comparison in a real-world monitoring experiment for the large aviation aluminum plate. Based on the results shown in the experiment, a big potential in real-time application is presented that the method can accurately and rapidly identify the bolt loosening by analyzing the acquired strain signal using proposed decision fusion system.

  20. The new structure of fibre glass reinforced plastics bolt

    Institute of Scientific and Technical Information of China (English)

    马念杰; 刘社育

    2003-01-01

    The develop actuality and direction of FRP(fibre glass reinforced plastics) bolt in the world are analyzed. The new type structure of FRP bolt was designed. Trial data indicate that, all kinds of capability target of this FRP bolt all achieve and exceed the country standard, substitute present metal bolt,wood bolt and bamboo bolt and other side bolt, it can gain magnitude technology and economy benefit. FRP bolt mechanization product line produce efficiency is high, its throughput a day are 750 base, this can meet demand of hit-small mining company.

  1. Stud bolt handling equipment for reactor vessel

    International Nuclear Information System (INIS)

    Reactor vessel stud bolt handling equipment includes means for transferring a stud bolt to a carrier from a parking station, or vice versa. Preferably a number of stud bolts are handled simultaneously. The transfer means may include cross arms rotatable about extendable columns, and the equipment is mounted on a mobile base for movement into and out of position. Each carrier comprises a tubular socket and an expandable sleeve to grip a stud bolt. (author)

  2. Assessment of rock bolt systems for underground waste storage

    International Nuclear Information System (INIS)

    A review of existing rock bolting systems was undertaken to assess their suitability in underground design for storage of nuclear waste. Unique engineering considerations are required due to the thermal pulse generated by the waste causing additional stress to the support system and possibly affecting anchorage stability. Field visits were made to four underground projects to assess the performance of a wide variety of rock bolt systems. Cable bolts, point anchor bolts, locally debonded full column cement grout bolts, and yieldable bolt systems show promise. Full scale testing of bolt systems is recommended, together with assessing temperature effects on grout strength and grout longterm stability

  3. Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts

    Science.gov (United States)

    Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

    2016-07-01

    Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests.

  4. Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts.

    Science.gov (United States)

    Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

    2016-07-01

    Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests. PMID:27475551

  5. Study on the material character steel big-end bolt

    Institute of Scientific and Technical Information of China (English)

    SHI Jian-jun; MA Nian-jie; ZHAN Ping; ZHANG Dian-li

    2008-01-01

    Based on the manufacturing method now used in our country,caused low bearing capacity in the bolt-end,which is a potential danger in the bolt supporting tunnel and a waste of money,and presented the new type strong steel big-end bolt can solve this problem.Analyzed the active state of the end of bolt by ANSYS,we can know that it is very disadvantage when bolt bore eccentric load.Contrasted with the different that common bolt and big-end bolt when they bore the same loading.The common bolt is bigger than the big-end bolt in stress value.Study on the processing technic of the new type of the strong steel big-end bolt,the new metal big-end bolt was produced by heat processing over big-end bolt and upset.From the microscopic examination on bolt metal,it is concluded that heat processing on the bolt-end refines the crystal grain of the metal material,which not only increase its extension but improve its property.Moreover the strength ability of the bolt material can be exerted completely.

  6. Study on the material character steel big-end bolt

    Institute of Scientific and Technical Information of China (English)

    SHI Jian-jun; MA Nian-jie; ZHAN Ping; ZHANG Dian-li

    2008-01-01

    Based on the manufacturing method now used in our country, caused low bear-ing capacity in the bolt-end, which is a potential danger in the bolt supporting tunnel and a waste of money, and presented the new type strong steel big-end bolt can solve this problem. Analyzed the active state of the end of bolt by ANSYS, we can know that it is very disadvantage when bolt bore eccentric load. Contrasted with the different that com-mon bolt and big-end bolt when they bore the same loading. The common bolt is bigger than the big-end bolt in stress value. Study on the processing technic of the new type of the strong steel big-end bolt, the new metal big-end bolt was produced by heat processing over big-end bolt and upset. From the microscopic examination on bolt metal, it is con-cluded that heat processing on the bolt-end refines the crystal grain of the metal material, which not only increase its extension but improve its property. Moreover the strength ability of the bolt material can be exerted completely.

  7. The modelling of bolted flange joints used with disc springs and tube spacers to reduce relaxation

    International Nuclear Information System (INIS)

    Bolted flange joints are prone to leakage when exposed to high temperature. In several cases, the root cause is relaxation that takes place as a result of material creep of the gasket, the bolt and the flange. One way to overcome this problem is to make the joint less stiff by introducing disc springs or the use of longer bolts with spacers. Although widely used, these two methods have no reliable analytical model that could be used to evaluate the exact number of washers or length of the bolts required to reduce relaxation to a minimum acceptable level. This paper describes an analytical model based on the flexibility and deflection interactions of the joint different elements including the axial stiffness of the flange and bolts, used to evaluate relaxation. The developed analytical flange model can accommodate either disc springs or longer bolts with spacer tubes to reduce the bolt load loss to a maximum acceptable value. This model is validated by comparison with the more accurate FEA findings. Calculation examples on a bolted flanged joint are presented to illustrate the suggested analytical calculation procedure.

  8. Behavior of Fiber Glass Bolts, Rock Bolts and Cable Bolts in Shear

    Science.gov (United States)

    Li, Xuwei; Aziz, Naj; Mirzaghorbanali, Ali; Nemcik, Jan

    2016-07-01

    This paper experimentally compares the shear behavior of fiber glass (FG) bolt, rock bolt (steel rebar bolt) and cable bolt for the bolt contribution to bolted concrete surface shear strength, and bolt failure mode. Two double shear apparatuses of different size were used for the study. The tensile strength, the shear strength and the deformation modulus of bolt control the shear behavior of a sheared bolted joint. Since the strength and deformation modulus of FG bolt, rock bolt and cable bolt obtained from uniaxial tensile tests are different, their shear behavior in reinforcing joints is accordingly different. Test results showed that the shear stiffness of FG bolted joints decreased gradually from the beginning to end, while the shear stiffness of joints reinforced by rock bolt and cable bolt decreased bi-linearly, which is clearly consistent with their tensile deformation modulus. The bolted joint shear stiffness was highly influenced by bolt pretension in the high stiffness stage for both rock bolt and cable bolt, but not in the low stiffness stage. The rock bolt contribution to joint shear strength standardised by the bolt tensile strength was the largest, followed by cable bolts, then FG bolts. Both the rock bolts and cable bolts tended to fail in tension, while FG bolts in shear due to their low shear strength and constant deformation modulus.

  9. Analytical large deformation shear strength for bolted rough discontinuous rock

    Institute of Scientific and Technical Information of China (English)

    LIU Bo(刘波); TAO Long-guang(陶龙光); YUE Zhong-qi(岳中琦)

    2004-01-01

    Presented a new analytical model for studying the shear-tensile large deformation behavior near the vicinity of joint interface for bolted rough discontinuous rock, and presented the formulation estimating global shear strength for bolted joints under shearing-tensile loads. The analytical strength curves of bolts contribution on reinforced discontinuous rocks as the function of joint displacements or deformation angle of a bolt at rock joints was obtained. Based on Barton's equation on JRC roughness profiles, the theoretical shearing strength of bolted rough joints was also established. Test results on bolted granite and marble specimen confirm the validity of the analytical approach.

  10. Research on the bolt supporting principal of developing entry

    Institute of Scientific and Technical Information of China (English)

    XIONG Ren-qin

    2004-01-01

    Based on the principle of rock-soil mechanics, the bolt supporting technology of mine roadway were researched, it is pointed out that the roadway's four corner bolt, the prestressed bolt and the extensible bolt play an important role in keeping road stable; it is also indicated that the walls of roadway safeguarded well is important in keeping road stable, which can make the bolt and surrounding rock load-bearing together; bolt and grounting technology can increase anchorage capacity, which is very applicable for soft rock supporting and developing entry.

  11. Prying Force Calculation and Design Method for T-shaped Tensile Connector with High Strength Bolt

    Institute of Scientific and Technical Information of China (English)

    Zhaoxin Hou; Guohong Huang; Chao Gong

    2015-01-01

    In order to establish the design method for T⁃shaped tensile connector with high strength bolt, the theoretical analysis is carried out. Firstly, it analyzes the performance of the connector and establishes prying force calculation model. Based on the model, prying force equation and function between bolt prying force and flange thickness is derived, and the min and max thickness requirement of flange plate under a certain tension load is then obtained. Finally, two simplified design methods of the connector are proposed, which are bolt pulling capacity method and flange plate bending capacity method.

  12. Piezoelectric Bolt Breakers and Bolt Fatigue Testers

    Science.gov (United States)

    Sherrit, Stewart; Badescu, Mircea; Bar-Cohen, Yoseph; Barengoltz, Jack; Heckman, Vanessa

    2008-01-01

    A proposed family of devices for inducing fatigue in bolts in order to break the bolts would incorporate piezoelectric actuators into resonant fixtures as in ultrasonic/ sonic drills/corers and similar devices described in numerous prior NASA Tech Briefs articles. These devices were originally intended primarily for use as safer, more-reliable, more-versatile alternatives to explosive bolts heretofore used to fasten spacecraft structures that must subsequently be separated from each other quickly on command during flight. On Earth, these devices could be used for accelerated fatigue testing of bolts. Fatigue theory suggests that a bolt subjected to both a constant-amplitude dynamic (that is, oscillatory) stress and a static tensile stress below the ultimate strength of the bolt material will fail faster than will a bolt subjected to only the dynamic stress. This suggestion would be applied in a device of the proposed type. The device would be designed so that the device and the bolt to be fatigue-tested or broken would be integral parts of an assembly (see figure). The static tension in the tightened bolt would apply not only the clamping force to hold the joined structures (if any) together but also the compression necessary for proper operation of the piezoelectric actuators as parts of a resonant structural assembly. The constant-amplitude dynamic stress would be applied to the bolt by driving the piezoelectric actuators with a sinusoidal voltage at the resonance frequency of longitudinal vibration of the assembly. The amplitude of the excitation would be made large enough so that the vibration would induce fatigue in the bolt within an acceptably short time. In the spacecraft applications or in similar terrestrial structural-separation applications, devices of the proposed type would offer several advantages over explosive bolts: Unlike explosive bolts, the proposed devices would be reusable, could be tested before final use, and would not be subject to

  13. High-Strength Bolt Corrosion Fatigue Life Model and Application

    Directory of Open Access Journals (Sweden)

    Wang Hui-li

    2014-01-01

    Full Text Available The corrosion fatigue performance of high-strength bolt was studied. Based on the fracture mechanics theory and the Gerberich-Chen formula, the high-strength bolt corrosion fracture crack model and the fatigue life model were established. The high-strength bolt crack depth and the fatigue life under corrosion environment were quantitatively analyzed. The factors affecting high-strength bolt corrosion fatigue life were discussed. The result showed that the high-strength bolt corrosion fracture biggest crack depth reduces along with the material yield strength and the applied stress increases. The material yield strength was the major factor. And the high-strength bolt corrosion fatigue life reduced along with the increase of material strength, the applied stress or stress amplitude. The stress amplitude influenced the most, and the material yield strength influenced the least. Low bolt strength and a low stress amplitude level could extend high-strength bolt corrosion fatigue life.

  14. Consideration on the earthquake-resistant margin of equipment base-bolts receiving the shearing load during seismic movements

    International Nuclear Information System (INIS)

    Seismic movements exceeding earthquake-resistance standards were recorded at the Kashiwazaki-Kariwa Nuclear Power Station during the scene of the Niigataken Chuestu-Oki Earthquake in 2007. No damages were reported for the safety-significant equipments and facilities representing functions of 'shut-down', 'cooling' and 'containment' because they were constructed with a large margin for seismic permissible values. Wherein, it is possible to clarify their safety by investigating how much a seismic margin is actually expected. In order to quantitatively evaluate the margin, we conducted a series of shearing tests using real specimens of equipment base-bolts on which a seismic load tends to concentrate, as an example of typical equipments at the Tokai Reprocessing Plant. This report summarized how much the shearing strength values of the specimens gave actual margins in comparison to the seismic permissible values. (author)

  15. Research on the mechanical property test of a new high-strength metal bolt

    Institute of Scientific and Technical Information of China (English)

    SHI Jian-jun; MA Nian-jie

    2011-01-01

    In order to study how to improve the overall performance of the operational metal bolt,based on the production process of an ordinary metal bolt used in understructure engineering,this paper focused on the existing problems of ordinary metal bolts identified by some survey and analysis.The results show that the structure of operational metal bolts is so unreasonable that the bolt tail is easily fractured by low load capacity.Furthermore,a new type of strong big-end metal bolt and its heat treatment and roughing processing technology were introduced.Through bolt tensile and metallographic tests,the property of the new big-end bolt was analyzed.The new findings indicate that after a special processing,the overall strength and plasticity of the bolt is greatly improved,and the grain of the bolt tail structure is refined,which would help build up favorable working conditions for bolt tails.

  16. Real time bolt preload monitoring using piezoceramic transducers and time reversal technique—a numerical study with experimental verification

    Science.gov (United States)

    Parvasi, Seyed Mohammad; Ho, Siu Chun Michael; Kong, Qingzhao; Mousavi, Reza; Song, Gangbing

    2016-08-01

    Bolted joints are ubiquitous structural elements, and form critical connections in mechanical and civil structures. As such, loosened bolted joints may lead to catastrophic failures of these structures, thus inspiring a growing interest in monitoring of bolted joints. A novel energy based wave method is proposed in this study to monitor the axial load of bolted joint connections. In this method, the time reversal technique was used to focus the energy of a piezoelectric (PZT)-generated ultrasound wave from one side of the interface to be measured as a signal peak by another PZT transducer on the other side of the interface. A tightness index (TI) was defined and used to correlate the peak amplitude to the bolt axial load. The TI bypasses the need for more complex signal processing required in other energy-based methods. A coupled, electro-mechanical analysis with elasto-plastic finite element method was used to simulate and analyze the PZT based ultrasonic wave propagation through the interface of two steel plates connected by a single nut and bolt connection. Numerical results, backed by experimental results from testing on a bolted connection between two steel plates, revealed that the peak amplitude of the focused signal increases as the bolt preload (torque level) increases due to the enlarging true contact area of the steel plates. The amplitude of the focused peak saturates and the TI reaches unity as the bolt axial load reaches a threshold value. These conditions are associated with the maximum possible true contact area between the surfaces of the bolted connection.

  17. Bolt Stress Monitor

    Science.gov (United States)

    1978-01-01

    In photo, an engineer is using a new Ultrasonic Bolt Stress Monitor developed by NASA's Langley Research Center to determine whether a bolt is properly tightened. A highly accurate device, the monitor is an important tool in construction of such structures as pressure vessels, bridges and power plants, wherein precise measurement of the stress on a tightened bolt is critical. Overtightened or undertightened bolts can fail and cause serious industrial accidents or costly equipment break-downs. There are a number of methods for measuring bolt stress. Most widely used and least costly is the torque wrench, which is inherently inaccurate; it does not take into account the friction between nut and bolt, which has an influence on stress. At the other end of the spectrum, there are accurate stress-measuring systems, but they are expensive and not portable. The battery-powered Langley monitor fills a need; it is inexpensive, lightweight, portable and extremely accurate because it is not subject to friction error. Sound waves are transmitted to the bolt and a return signal is received. As the bolt is tightened, it undergoes changes in resonance due to stress, in the manner that a violin string changes tone when it is tightened. The monitor measures the changes in resonance and provides a reading of real stress on the bolt. The device, patented by NASA, has aroused wide interest and a number of firms have applied for licenses to produce it for the commercial market.

  18. Combined In-Plane and Through-the-Thickness Analysis for Failure Prediction of Bolted Composite Joints

    Science.gov (United States)

    Kradinov, V.; Madenci, E.; Ambur, D. R.

    2004-01-01

    Although two-dimensional methods provide accurate predictions of contact stresses and bolt load distribution in bolted composite joints with multiple bolts, they fail to capture the effect of thickness on the strength prediction. Typically, the plies close to the interface of laminates are expected to be the most highly loaded, due to bolt deformation, and they are usually the first to fail. This study presents an analysis method to account for the variation of stresses in the thickness direction by augmenting a two-dimensional analysis with a one-dimensional through the thickness analysis. The two-dimensional in-plane solution method based on the combined complex potential and variational formulation satisfies the equilibrium equations exactly, and satisfies the boundary conditions and constraints by minimizing the total potential. Under general loading conditions, this method addresses multiple bolt configurations without requiring symmetry conditions while accounting for the contact phenomenon and the interaction among the bolts explicitly. The through-the-thickness analysis is based on the model utilizing a beam on an elastic foundation. The bolt, represented as a short beam while accounting for bending and shear deformations, rests on springs, where the spring coefficients represent the resistance of the composite laminate to bolt deformation. The combined in-plane and through-the-thickness analysis produces the bolt/hole displacement in the thickness direction, as well as the stress state in each ply. The initial ply failure predicted by applying the average stress criterion is followed by a simple progressive failure. Application of the model is demonstrated by considering single- and double-lap joints of metal plates bolted to composite laminates.

  19. 参数化建模的螺栓法兰连接刚度分析%Stiffness analysis of bolted flange joint based on parameterized modeling

    Institute of Scientific and Technical Information of China (English)

    蒋国庆; 李家文; 唐国金

    2014-01-01

    为分析几何参数对螺栓法兰连接刚度的影响,用 MSC.Patran 软件的二次开发工具 PCL(Patran Command Language)建立了螺栓法兰连接的参数化模型。研究了螺栓法兰连接刚度随连接结构几何参数的变化规律并进行了灵敏度分析。经分析可知,连接结构刚度对开孔位置比例参数最敏感,其次是上法兰厚度。当上部段长度大于某一数值时,连接结构刚度对上部段长度参数不敏感,这一结论能为连接结构动力学简化建模提供一定理论参考。%In order to analyze the effects of geometric parameters on the stiffness of bolted flange joint,a parameterized model of bolted flange joint was constructed by using PCL (Patran Command Language)on the platform of software MSC.Patran.The law of the stiffness of bolted flange joint with the change of geometric parameters was studied,and the sensitivity of geometric parameters was analyzed based on the parameterized model.The results show that the ratio of the location of hole is the most sensitive factor to the stiffness of bolted flange joint,and the next one is thickness of upper flange.When the length of upper body is up to a const,the stiffness of bolted flange joint is insensitive to the length of upper body,and this conclusion can provide a reference to simplify the dynamic model of joint.

  20. Parameters determination and bolting control of gateway floor

    Institute of Scientific and Technical Information of China (English)

    GOU Pan-feng; XlN Ya-jun

    2011-01-01

    Gateway floor heave control is the key to guarantee mine safe and efficient production.Through analysis of floor instability characteristics and bolting control,gateway floor strata show second level stress under abutment pressure,which causes plastic flow failure in floor strata; gateway floor instability shows mainly shear-break slippage of “triangle sliding body”.Mechanics of floor bolting is mainly a function of connection and combination.Main area of bolting control lies in two gateway floor angles.The paper analyzes mechanics principle of gateway floor instability,constructs stability mechanics model of gateway floor bolting,obtains gateway floor stability criterion of different bolting angles and optimum formula of bolting parameters,carries out the engineering example,and guides better field application.It provides theoretical base for bolting gateway floor instability control.

  1. Bolting Cabin Assistance System Using a Sensor Network

    Directory of Open Access Journals (Sweden)

    Yung-Hak Mo

    2012-10-01

    Full Text Available The bolting cabin assistance system prevents operators from facing dangerous situations. This system consists of a bolting robot control system and a top view supervisory system. In order to control the bolting robot, circular Hough transforms and fuzzy reasoning are used. First, the circular Hough transform roughly estimates the location of the bolt hole. After that, errors of estimation are compensated for using fuzzy reasoning. In order to track a bolt hole, a region of interest (ROI is used. By setting the region in which to search for a bolt hole, the algorithm tracks the location of the bolt hole. In order to choose an ROI, a template‐based matching algorithm is used. In order to make the top view supervisory system, four cameras are installed at the left, right, front and back of the robot. The four individual images from the various cameras are combined to make the top view image after correcting for distortion.

  2. The design and testing of subscale smart aircraft wing bolts

    International Nuclear Information System (INIS)

    Presently costly periodic inspection is vital in guaranteeing the structural integrity of aircraft. This investigation assesses the potential for significantly reducing aircraft maintenance costs without modification of aircraft structures by implementing smart wing bolts, manufactured from TRIP steel, which can be monitored for damage in situ. TRIP steels undergo a transformation from paramagnetic austenite to ferromagnetic martensite during deformation. Subscale smart aircraft wing bolts were manufactured from hot rolled TRIP steel. These wing bolts were used to demonstrate that washers incorporating embedded inductance coils can be utilized to measure the martensitic transformation occurring in the TRIP steel during bolt deformation. Early in situ warning of a critical bolt stress level was thereby facilitated, potentially reducing the costly requirement for periodic wing bolt removal and inspection. The hot rolled TRIP steels that were utilized in these subscale bolts do not however exhibit the mechanical properties required of wing bolt material. Thus warm rolled TRIP steel alloys were also investigated. The mechanical properties of the best warm rolled TRIP steel alloy tested almost matched those of AISI 4340. The warm rolled alloys were also shown to exhibit transformation before yield, allowing for earlier warning when overload occurs. Further work will be required relating to fatigue crack detection, environmental temperature fluctuation and more thorough material characterization. However, present results show that in situ early detection of wing bolt overload is feasible via the use of high alloy warm rolled TRIP steel wing bolts in combination with inductive sensor embedded washers. (paper)

  3. The design and testing of subscale smart aircraft wing bolts

    Science.gov (United States)

    Vugampore, J. M. V.; Bemont, C.

    2012-07-01

    Presently costly periodic inspection is vital in guaranteeing the structural integrity of aircraft. This investigation assesses the potential for significantly reducing aircraft maintenance costs without modification of aircraft structures by implementing smart wing bolts, manufactured from TRIP steel, which can be monitored for damage in situ. TRIP steels undergo a transformation from paramagnetic austenite to ferromagnetic martensite during deformation. Subscale smart aircraft wing bolts were manufactured from hot rolled TRIP steel. These wing bolts were used to demonstrate that washers incorporating embedded inductance coils can be utilized to measure the martensitic transformation occurring in the TRIP steel during bolt deformation. Early in situ warning of a critical bolt stress level was thereby facilitated, potentially reducing the costly requirement for periodic wing bolt removal and inspection. The hot rolled TRIP steels that were utilized in these subscale bolts do not however exhibit the mechanical properties required of wing bolt material. Thus warm rolled TRIP steel alloys were also investigated. The mechanical properties of the best warm rolled TRIP steel alloy tested almost matched those of AISI 4340. The warm rolled alloys were also shown to exhibit transformation before yield, allowing for earlier warning when overload occurs. Further work will be required relating to fatigue crack detection, environmental temperature fluctuation and more thorough material characterization. However, present results show that in situ early detection of wing bolt overload is feasible via the use of high alloy warm rolled TRIP steel wing bolts in combination with inductive sensor embedded washers.

  4. Computerized UT system for stud bolt

    International Nuclear Information System (INIS)

    Cracking of stud bolts used in steam turbine casing, valve and pressure vessel has caused concern regarding the safety and reliability of power plants. In order to detect harmful cracks in early state, the improvement of UT technique is required. As regarding the ultrasonic inspection technique, a longitudinal beam technique and/or an angle beam technique are generally used. The authors report their development of a computerized UT system for bolt inspection and improvement of the angle beam technique

  5. Health monitoring of 90° bolted joints using fuzzy pattern recognition of ultrasonic signals

    International Nuclear Information System (INIS)

    Bolted joints are important parts for aerospace structures. However, there is a significant risk associated with assembling bolted joints due to potential human error during the assembly process. Such errors are expensive to find and correct if exposed during environmental testing, yet checking the integrity of individual fasteners after assembly would be a time consuming task. Recent advances in structural health monitoring (SHM) can provide techniques to not only automate this process but also make it reliable. This integrity monitoring requires damage features to be related to physical conditions representing the structural integrity of bolted joints. In this paper an SHM technique using ultrasonic signals and fuzzy pattern recognition to monitor the integrity of 90° bolted joints in aerospace structures is described. The proposed technique is based on normalized fast Fourier transform (NFFT) of transmitted signals and fuzzy pattern recognition. Moreover, experimental observations of a case study on an aluminum 90° bolted joint are presented. We demonstrate the ability of the proposed method to efficiently monitor and indicate bolted joint integrity. (paper)

  6. Optimization of Bolt Stress

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    The state of stress in bolts and nuts with ISO metric thread design is examined and optimized. The assumed failure mode is fatigue so the applied preload and the load amplitude together with the stress concentrations define the connection strength. Maximum stress in the bolt is found at, the fillet...... under the head, at the thread start or at the thread root. To minimize the stress concentration shape optimization is applied....

  7. An analysis of bolted opening structure and development of analysis expert system using ANSYS

    International Nuclear Information System (INIS)

    Bolted opening structures is widely applied for class 1 machinery of nuclear plant with strict design requirement. As the shape of the bolted opening structure is non-axisymmetric due to the existence of stud bolts although it is almost axi-symmetric, 3D analysis is required to satisfy such kind of design requirements. Because as much as possible trial computations are need to get an optimal design condition in the limited period of basic design, an easy and fast analysis tool is useful in the design stage. In the paper, a transformation technique of non-axisymmetric problem into quasi-axisymmetric has been proposed based on the general purpose commercial code ANSYS. Both the pre-processor which incorporates the technique and prepares data and post-processor which prepares arranged results from the huge output of commercial code have been developed to help the design engineers. (author)

  8. Characteristic Evaluation on Bolt Stress by Ultrasonic Nondestructive Methods

    Directory of Open Access Journals (Sweden)

    Qinxue Pan

    2015-01-01

    Full Text Available Based on the acoustoelasticity theory, a certain relationship exists between ultrasonic velocity and stress. By combining shear and longitudinal waves, this paper provides a nondestructive method of evaluating axial stress in a tightened bolt. For measuring the bolt axial stress in different situations, such as under low or high loads, this paper provides guidelines for calculating the stress for a given load factor. Experimental and calculated results were compared for three bolt test samples: an austenitic stainless steel bolt (A2-70 and low-carbon steel 4.8 and 8.8 bolts. On average, the experimental results were in good agreement with those obtained through calculations, thus providing a nondestructive method for bolt stress measurements.

  9. Stress wave propagation in supporting bolts: A test for bolt support quality

    Institute of Scientific and Technical Information of China (English)

    Wu Rui; Xu Jinhai; Li Chong; Zhou Baojing; Ma Qianqian; Wang Zhongliang

    2012-01-01

    A test method for the non-destructive determination of bolt length,anchoring length,and bolt body force is described.This addresses the problems of low accuracy,limited number of data,and untimely warning signs encountered with existing test methods.Numerical simulations of the bolt,resin,and rock system show that the length accuracy when using the velocity wave is lower than when using the acceleration wave.It is accepted practice to use the acceleration wave for length tests because of improved signal to noise ratios of the waveforms.Laboratory and in situ underground tests showed that the precision of the measurements meets field requirements.Using this method the anchor properties of each single bolt and,thus,the safety of the entire roadway support may be evaluated.

  10. Overall bolt stress optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    The state of stress in bolts and nuts with International Organization for Standardization metric thread design is examined and optimized. The assumed failure mode is fatigue, so the applied preload and the load amplitude together with the stress concentrations define the connection strength....... Maximum stress in the bolt is found at the fillet under the head, at the thread start, or at the thread root. To minimize the stress concentration, shape optimization is applied. Nut shape optimization also has a positive effect on the maximum stress. The optimization results show that designing a nut......, which results in a more evenly distribution of load along the engaged thread, has a limited influence on the maximum stress due to the stress concentration at the first thread root. To further reduce the maximum stress, the transition from bolt shank to the thread must be optimized. Stress reduction...

  11. Bolt Analysis Program

    Science.gov (United States)

    Travis, Brandon E.

    2004-01-01

    In designing and testing bolted joints there are multiple parameters to be considered and calculations that must be performed to predict the joint behavior. Each different set of parameters may call for a different set of equations. Determining every parameter in each bolted joint is impractical and in many cases impossible. On the other hand, it is much easier to reduce these calculations to a universal set that can be used for all bolted joints. This is the purpose of the Bolt Analysis Program. My project under the Mechanical and Rotating Systems branch of the Engineering Development and Analysis Division was to take the Bolt Analysis Program Version 2.0 and update the program to a modem and user-friendly format. Version 2.0 of the Bolt Analysis Program is a useful program, but lacks the dynamic capabilities that are needed for current applications. Version 2.0 of the Bolt Analysis Program was written in 1993 using the Pascal programming language in a DOS format. This program allows you to input data in a step-by-step format, calculates the data, and then on a final screen displays the input and the output fiom the calculations. Version 2.0 is still applicable for all bolted joint anaiysis, but has updates that are desired. First, the program runs in DOS format. With the applications available today, my mentor decided it would be best to update the program into Excel using Visual Basic for Applications (VBA). This would allow the program to have multiple Graphical User Interfaces (GUI s) while retaining all functions of the previous program. Version 2.0 only allows you to input data in a step-by-step process. If you make a mistake and need to go back, you must run through the entire program before you can return to fix your error. This becomes tedious when needing to change one parameter or test multiple sets of data. In Version 3.0, the program allows you to enter and change data at any time while displaying real-time output data. If you realize an error, it is

  12. Investigation of Reliabilities of Bolt Distances for Bolted Structural Steel Connections by Monte Carlo Simulation Method

    Directory of Open Access Journals (Sweden)

    Ertekin Öztekin Öztekin

    2015-12-01

    Full Text Available Design of the distance of bolts to each other and design of the distance of bolts to the edge of connection plates are made based on minimum and maximum boundary values proposed by structural codes. In this study, reliabilities of those distances were investigated. For this purpose, loading types, bolt types and plate thicknesses were taken as variable parameters. Monte Carlo Simulation (MCS method was used in the reliability computations performed for all combination of those parameters. At the end of study, all reliability index values for all those distances were presented in graphics and tables. Results obtained from this study compared with the values proposed by some structural codes and finally some evaluations were made about those comparisons. Finally, It was emphasized in the end of study that, it would be incorrect of the usage of the same bolt distances in the both traditional designs and the higher reliability level designs.

  13. NUMERICAL SIMULATION ANALYSES ON REINFORCEMENT FUNCTION OF THE TENSIONED AND GROUTED BOLTS

    Institute of Scientific and Technical Information of China (English)

    邹喜正; 李华祥

    1998-01-01

    The purpose of the paper is to calculate the equivalent mechanics parameters of reinforced surroundings, which is based on the assume that the reinforcement of bolts is equivalent to the improvement of mechanics parameters of surroundings and combines with site engineering practice. Use numerical simulation analysis to study the reinforcement mechanism of full length bolts, thus to provide theoretical bases for bolting design.

  14. Turbine casing bolts; a life assessment and bolt replacement strategy

    Energy Technology Data Exchange (ETDEWEB)

    Bulloch, J.H. [ESB, Power Generation, Dublin (Ireland)

    1998-12-31

    The present presentation describes a detailed study concerning the life assessment and replacement strategy of large turbine casing bolts in a 120 MW steam raising unit. After 122000 hours service, circa 1991/92, the Cr-Mo-V steel casing bolts, involving a total of 184 bolts, from two identical 120 MW units, termed Units 1 and 2, were examined to establish the extent of Reverse Temper Embrittlement, RTE, and creep damage suffered during service. The bolt replacement plans for the two units were as follows; Unit 1 bolts were completely replaced with new bolts while Unit 2 embrittled bolts were withdrawn from service and replaced with Non- Embrittled bolts from Unit 1; basically Unit 2 bolts were made up from a mixture of Unit 1 and 2 Non- Embrittled bolts which had been in service for 122000 hours. Remnant life assessments, concerning both embrittlement and creep damage aspects, were earned out on this series of easing bolts at service times 122000, 150000 and 200000 hours. These assessments involved the use of general embrittlement and creep damage laws which were empirically derived and concerned such parameters as microstructural grain size, bulk phosphorus content and accumulated service strain. (orig.) 7 refs.

  15. The ITER EC H and CD upper launcher: Design, analysis and testing of a bolted joint for the Blanket Shield Module

    Energy Technology Data Exchange (ETDEWEB)

    Gessner, Robby, E-mail: robby.gessner@kit.edu [Karlsruhe Institute of Technology, Institute for Applied Materials, P.O. Box 3640, D-76021 Karlsruhe (Germany); Aiello, Gaetano; Grossetti, Giovanni; Meier, Andreas [Karlsruhe Institute of Technology, Institute for Applied Materials, P.O. Box 3640, D-76021 Karlsruhe (Germany); Ronden, Dennis [DIFFER – Dutch Institute for Fundamental Energy Physics, P.O. Box 1207, NL-3430 BE Nieuwegein (Netherlands); Spaeh, Peter; Scherer, Theo; Schreck, Sabine; Strauss, Dirk; Vaccaro, Alessandro [Karlsruhe Institute of Technology, Institute for Applied Materials, P.O. Box 3640, D-76021 Karlsruhe (Germany)

    2013-10-15

    Highlights: ► The BSM of the ECH Launcher is attached to the Launcher Main Frame by a bolted joint. ► The bolts were designed as “captive” in order to avoid their accidental removal from the joint. ► The bolted flange connection using two sets of 15 captive bolts (M22 × 2) placed along the sides. ► The captive bolt design is based on a concept that uses a dedicated spring ring, a standard spiral spring and a tensioning screw with two threads to secure the bolts in a form-locking stop. -- Abstract: The final design of the structural system for the ITER EC H and CD upper launcher is in progress. Many design features of the preliminary design are under revision with the aim to achieve the built-to-print-status. This paper deals with design and analysis of a bolted joint for the Blanket Shield Module with special perspective on Remote Handling capability. The BSM of the ECH Launcher is attached to the Launcher Main Frame by a bolted joint conceived so that in the Hot Cell Facility, RH maintenance can be performed on internal components. The joint must be capable to resist very high Electro-Magnetic loads from disruptions, while it has to sustain substantial thermal cycling during operation. Thus the need for a rigid and reliable design is essential. Beside the set of pre-stressed bolts the flanges were therefore equipped with additional shear keys to divert radial moments away from the bolts. Main focus of the work performed was the mechanical design of the joint and the assessment of the structural integrity with respect to the loads applied and its capability for maintenance by RH procedures. To fulfill a major aspect of the RH requirements, the bolts were designed as “captive” in order to avoid their accidental removal from the joint. The captive bolt design is based on a concept that uses a dedicated spring ring, a standard spiral spring and a tensioning screw with two threads to secure the bolts in a form-locking stop. The final approval phase of

  16. Analysis on the anchor mechanism of the full length resin bolt

    Institute of Scientific and Technical Information of China (English)

    宋彦波; 刘洪涛

    2003-01-01

    The purpose of this paper is to reveal the stress distribution characteristic along the full length anchor bolt. Based on the mechanic model set up, the author calculated the anchor mechanism of the full length resin rock-bolt. The stress distribution characteristic is different according to different type of surrounding-rock. The conclusion is important to optimize the roadway bolt support design.

  17. Bolt Thread Stress Optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2012-01-01

    Designs of threaded fasteners are controlled by different standards, and the number of different thread definitions is large. The most commonly used thread is probably the metric ISO thread, and this design is therefore used in this paper. Thread root design controls the stress concentration factor...... of threads and therefore indirectly the bolt fatigue life. The root shape is circular, and from shape optimization for minimum stress concentration it is well known that the circular shape is seldom optimal. An axisymmetric Finite Element (FE) formulation is used to analyze the bolted connection, and a study...... is performed to establish the need for contact modeling with regard to finding the correct stress concentration factor. Optimization is performed with a simple parameterization with two design variables. Stress reduction of up to 9% is found in the optimization process, and some similarities are found...

  18. Regulatory analysis for the resolution of Generic Safety Issue 29: Bolting degradation or failure in nuclear power plants

    International Nuclear Information System (INIS)

    Generic Safety Issue (GSI)-29 deals with staff concerns about public risk due to degradation or failure of safety-related bolting in nuclear power plants. The issue was initiated in November 1982. Value-impact studies of a mandatory program on safety-related bolting for operating plants were inconclusive: therefore, additional regulatory requirements for operating plants could not be justified in accordance with provisions of 10 CFR 50.109. In addition, based on operating experience with bolting in both nuclear and conventional power plants, the actions already taken through bulletins, generic letters, and information notices, and the industry-proposed actions, the staff concluded that a sufficient technical basis exists for the resolution of GSI-29. The staff further concluded that leakage of bolted pressure joints is possible but catastrophic failure of a reactor coolant pressure boundary joint that will lead to significant accident sequences is highly unlikely. For future plants, it was concluded that a new Standard Review Plant section should be developed to codify existing bolting requirements and industry-developed initiatives. 9 refs., 1 tab

  19. Stress Evolution in Roadway Rock Bolts During Mining in a Fully Mechanized Longwall Face, and an Evaluation of Rock Bolt Support Design

    Science.gov (United States)

    Zhang, Kai; Zhang, Guimin; Hou, Rongbin; Wu, Yu; Zhou, Hongqi

    2015-01-01

    Rock bolts are widely used in coal mines throughout China. Approximately 8,000 km of roadways are excavated in coal mines every year in China, 80 % of which are supported by rock bolts. At present, the design of rock bolt support schemes is mainly based on analogies and experience from previous projects. In the present study, in order to evaluate the design of rock bolt support in roadways, several cross sections of a roadway were monitored for rock bolt stress during the roadway excavation and mining. The study results show that the stress in the rock bolts varied in the areas 20 m behind the excavating face and 30 m ahead of the mining face. For the rock bolts observed in this study, the max axial force was within the design limit of the bolts, thus the support design was shown to be acceptable. Then, numerical simulation was performed using FLAC3D to investigate the stress evolution in the rock bolts during the mining of the fully mechanized longwall face. The simulation results show an overall agreement with the in situ measurements. Finally, parametric study pertaining to length, anchorage length, and rock bolt spacing was carried out with the numerical model, and several suggestions for the support design were proposed.

  20. STUDY ON GATEWAY BOLTING EXCAVATED IN INCLINED COAL SEAM

    Institute of Scientific and Technical Information of China (English)

    陶连金; 王泳嘉; 张倬元

    1997-01-01

    A typical gateway is analyzed using fully-deformable discrete element method. The fractured zone around the gateway is measured in field. Based on the measurement results and theoretical analysis, a comprehensive support scheme adopting bolt and steel belt is proposed. Discrete element method is used to assess the bolting scheme, and displacement monitoring in field is also carried out. Having been put into practice, it is proved that the scheme is both successful and rational. According to theoretical analysis and monitoring in field, some importan tkeynotes that should be noticed in gateway bolting practice are presented as well.

  1. Rock bolting and pull out test on rebar bolts

    OpenAIRE

    Kristjánsson, Gunnar

    2014-01-01

    Pull out tests were carried out in the laboratory of rock mechanics at Norwegian University of Science and Technology (NTNU) for the purpose of determining the critical embedment length of fully grouted rebar bolts. The 20-mm rebar bolts and the grouting material, “the Rescon Zinc bolt cement” used in the testing are widely used in underground projects in Norway. Different embedment lengths, ranging from 10 cm to 40 cm, were employed in the tests under different water-cement ratios ...

  2. Preloading of bolted connections in nuclear reactor component supports

    Energy Technology Data Exchange (ETDEWEB)

    Yahr, G T

    1984-10-01

    A number of failures of threaded fasteners in nuclear reactor component supports have been reported. Many of those failures were attributed to stress corrosion cracking. This report discusses how stress corrosion cracking can be avoided in bolting by controlling the maximum bolt preloads so that the sustained stresses in the bolts are below the level required to cause stress corrosion cracking. This is a basic departure from ordinary bolted joint design where the only limits on preload are on the minimum preload. Emphasis is placed on the importance of detailed analysis to determine the acceptable range of preload and the selection of a method for measuring the preload that is sufficiently accurate to ensure that the preload is actually within the acceptable range. Procedures for determining acceptable preload range are given, and the accuracy of various methods of measuring preload is discussed.

  3. Mechanics of Re-Torquing in Bolted Flange Connections

    Science.gov (United States)

    Gordon, Ali P.; Drilling Brian; Weichman, Kyle; Kammerer, Catherine; Baldwin, Frank

    2010-01-01

    It has been widely accepted that the phenomenon of time-dependent loosening of flange connections is a strong consequence of the viscous nature of the compression seal material. Characterizing the coupled interaction between gasket creep and elastic bolt stiffness has been useful in predicting conditions that facilitate leakage. Prior advances on this sub-class of bolted joints has lead to the development of (1) constitutive models for elastomerics, (2) initial tightening strategies, (3) etc. The effect of re-torque, which is a major consideration for typical bolted flange seals used on the Space Shuttle fleet, has not been fully characterized, however. The current study presents a systematic approach to characterizing bolted joint behavior as the consequence of sequentially applied torques. Based on exprimenta1 and numerical results, the optimal re-torquing parameters have been identified that allow for the negligible load loss after pre-load application

  4. Ultrasonic extensometer measures bolt preload

    Science.gov (United States)

    Daniels, C. M., Jr.

    1978-01-01

    Extensometer using ultrasonic pulse reflections to measure elongations in tightened belts and studs is much more accurate than conventional torque wrenches in application of specified preload to bolts and other threaded fasteners.

  5. An overview of bolt failures in nuclear systems

    International Nuclear Information System (INIS)

    The S.M. Stoller Corporation (SMSC) conducted a survey a material failures in nuclear plant systems using two data bases, i.e., Operating Plant Experience Code and Nuclear Power Experience. Information from the data bases was used to classify material failures as a function of time, type of plant, and type of component. Bolting failures represented 2 percent of all pressurized water reactor (PWR) material failures and 1 percent of all boiling water reactor (BWR) material failures. The majority of the PWR bolt failures have been due to stress corrosion of Inconel X-750 control rod guide tube support pins in Westinghouse reactors and A-286 reactor core thermal shield and core barrel support bolts in B ampersand W reactors. An improved mechanical design and aging treatment are expected to improve the stress corrosion resistance of Inconel X-750 pins. The replacement A-286 bolts employ peening in the head to shank area, rounded thread radii, machining versus hot forging of the head, a locking device to prevent loose parts, and reduced stresses as product improvements. A portion of reactor external PWR bolt failures were due to inadvertent boric acid corrosion of carbon, low alloy, and martensitic steels. Other causes of outside reactor PWR bolting failures were excessive stress, chloride-induced stress corrosion, oxidation, and fatigue of various materials in a variety of applications. BWR bolt failures have been relatively few and apparently not generic. Stress corrosion failures of Inconel X-750 fuel channel fasteners are reported judged to be caused by excess stress, nonoptimal heat treatment, and nonoptimal material selection. No failures have been reported in BWR alloy X-750 channel fastener bolts loaded to approximately 50-percent yield. 3 figs., 6 tabs

  6. Experimental Study on Methane Explosion Ignited by Sparks of Cable Bolt Breakage

    Institute of Scientific and Technical Information of China (English)

    MA Wen-ding; XU Jia-lin; ZHANG Shao-hua

    2004-01-01

    An experimental device was designed for studying methane explosion ignited by sparks of cable bolt breakage. With the methane concentration being in explosion range, a series of experiments were conducted to study the law of spark generation during cable bolt breakage and the probability of methane explosion caused by the spark. The results show that the probability of generating sparks during cable bolt breakage is 50%. The spark generated by the breakage of steel cable bolt strand can't ignite a methane explosion. A detection was carried out using infrared-ray imaging apparatus (IRIA) to measure temperature of the spark generated by cable bolt breakage. It is indicated that the maximum temperature of the spark generated by cable bolt breakage is far less than the required ignition temperature for a methane explosion.

  7. Bolt study - behaviour of bolts in drop accident scenarios of the Nirex 3m3 Box ILW package

    International Nuclear Information System (INIS)

    The mission of Nirex is to provide the UK with safe, environmentally sound and publicly acceptable options for the long-term management of radioactive materials. One of the key tasks is to ensure that waste is packaged by waste producers in a form which is suitable for safe storage, transport, handling and potential disposal. In pursuit of this key requirement, Nirex has developed specifications to set the standard for the design and performance of waste packages, and has developed standard containers for the packaging of intermediate level (ILW) and some low level waste (LLW) - one of these is the 3m3 Box for immobilised operational and decommissioning ILW. The dimension envelope of this package is 1716 mm x 1716 mm in plan with 430 mm corner radii, 1226 mm tall. The maximum loaded weight is 12 tonnes. A generic design of this container has been developed, which is a welded structure manufactured from austenitic stainless steel (EN 10088-2 steel number 1.4404). The lid is connected to the body by 28 stainless steel bolts. An extensive study was carried out to develop a robust FE model of the bolts. The specific focus of this work was to use improved bolt modelling to optimize the design of the 3m3 Box, although this work could be applied to other bolted containers. This paper presents a summary of the findings from the study as follows: 1. Development of a FE bolt model for application in a 3m3 Box model. 2. Development and execution of a bolt testing programme which included tensile and shear tests on a total of 88 bolts, representing four grades of stainless steel materials, three thread sizes, and two geometries at three strain rates. 3. Benchmarking of the FE bolt model that can be used with confidence in simulating waste package behaviour in drop scenarios

  8. Bolt study - behaviour of bolts in drop accident scenarios of the Nirex 3m{sup 3} Box ILW package

    Energy Technology Data Exchange (ETDEWEB)

    Turner, G. [United Kingdom Nirex Ltd., Harwell (United Kingdom); Tso, C.F. [Arup, London (United Kingdom)

    2004-07-01

    The mission of Nirex is to provide the UK with safe, environmentally sound and publicly acceptable options for the long-term management of radioactive materials. One of the key tasks is to ensure that waste is packaged by waste producers in a form which is suitable for safe storage, transport, handling and potential disposal. In pursuit of this key requirement, Nirex has developed specifications to set the standard for the design and performance of waste packages, and has developed standard containers for the packaging of intermediate level (ILW) and some low level waste (LLW) - one of these is the 3m{sup 3} Box for immobilised operational and decommissioning ILW. The dimension envelope of this package is 1716 mm x 1716 mm in plan with 430 mm corner radii, 1226 mm tall. The maximum loaded weight is 12 tonnes. A generic design of this container has been developed, which is a welded structure manufactured from austenitic stainless steel (EN 10088-2 steel number 1.4404). The lid is connected to the body by 28 stainless steel bolts. An extensive study was carried out to develop a robust FE model of the bolts. The specific focus of this work was to use improved bolt modelling to optimize the design of the 3m{sup 3} Box, although this work could be applied to other bolted containers. This paper presents a summary of the findings from the study as follows: 1. Development of a FE bolt model for application in a 3m{sup 3} Box model. 2. Development and execution of a bolt testing programme which included tensile and shear tests on a total of 88 bolts, representing four grades of stainless steel materials, three thread sizes, and two geometries at three strain rates. 3. Benchmarking of the FE bolt model that can be used with confidence in simulating waste package behaviour in drop scenarios.

  9. A Synthetic Phased Array Surface Acoustic Wave Sensor for Quantifying Bolt Tension

    Directory of Open Access Journals (Sweden)

    Rasim Guldiken

    2012-09-01

    Full Text Available In this paper, we report our findings on implementing a synthetic phased array surface acoustic wave sensor to quantify bolt tension. Maintaining proper bolt tension is important in many fields such as for ensuring safe operation of civil infrastructures. Significant advantages of this relatively simple methodology is its capability to assess bolt tension without any contact with the bolt, thus enabling measurement at inaccessible locations, multiple bolt measurement capability at a time, not requiring data collection during the installation and no calibration requirements. We performed detailed experiments on a custom-built flexible bench-top experimental setup consisting of 1018 steel plate of 12.7 mm (½ in thickness, a 6.4 mm (¼ in grade 8 bolt and a stainless steel washer with 19 mm (¾ in of external diameter. Our results indicate that this method is not only capable of clearly distinguishing properly bolted joints from loosened joints but also capable of quantifying how loose the bolt actually is. We also conducted detailed signal-to-noise (SNR analysis and showed that the SNR value for the entire bolt tension range was sufficient for image reconstruction.

  10. Model-based inverse methods for sizing cracks of varying shape and location in bolt-hole eddy current (BHEC) inspections

    Science.gov (United States)

    Aldrin, John C.; Sabbagh, Harold A.; Zhao, Liming; Sabbagh, Elias; Murphy, R. Kim; Keiser, Mark; Flores-Lamb, Jennifer; Forsyth, David S.; Motes, Doyle; Lindgren, Eric A.; Mooers, Ryan

    2016-02-01

    A comprehensive approach is presented to perform model-based inversion of crack characteristics using bolt hole eddy current (BHEC) techniques. Data was acquired for a wide range of crack sizes and shapes, including mid-bore, corner and through-thickness crack types, and from both standard eddy current hardware and a prototype BHEC system with z-axis position encoding. Signal processing algorithms were developed to process and extract features from the 2D data sets, and inversion algorithms using VIC-3D generated surrogate models were used for inverting crack size. New model results are presented, which now address the effect of having a corner crack at an edge and a through crack adjacent to two edges. A two-step inversion process was implemented that first evaluates the material layer thickness, crack type and location, in order to select the most appropriate VIC-3D surrogate model for subsequent crack sizing inversion step. Inversion results for select mid-bore, through and corner crack specimens are presented where sizing performance was found to be satisfactory in general, but also depend on the size and location of the flaw.

  11. Result from systematic compilation of barrel bolt findings in S/KWU type PWRs in the context of computational analysis

    International Nuclear Information System (INIS)

    In 2005 intergranular stress corrosion cracking (IGSCC) of barrel bolts was observed in several S/KWU type PWRs. The bolts, known as star bolts, are made of SS type 316 Ti (German Material No. 1.4571 K) bars which are cold worked to adjust the required mechanical properties. This damage mechanism was so far less understood for PWR primary conditions. Therefore an extended joint research program was launched by AREVA GmbH and VGB e.V. to clarify the specific conditions which contributed to the observed findings on barrel bolts. A systematic analysis of the IGSCC affecting parameters as material, heats, environment and mechanical load was performed based on a plant data compilation from all six S/KWU PWRs with comparable core barrel design using barrel and baffle bolts made from type 316Ti. Using the outcome of this systematic data compilation additional computational fluid dynamics calculations in combination with radiolysis calculations were performed. The results showed that by a combination of reduced volume exchange by local flow conditions and radiolysis reactions forming oxidizing species as dissolved oxygen and/or hydrogen peroxide may locally affect the corrosion behavior of cold worked austenitic stainless steels. Therefore, small local volumes with oxidizing water chemistry conditions are assumed to lead to the IGSCC of cold worked type 316Ti. The comparison of the initial cold worked microstructure by TEM with the cold worked and in service irradiated microstructure (void formation, dislocation loop density, etc.) clearly reveals that neutron irradiation hardening in terms of IASCC (Irradiation-Assisted Stress Corrosion Cracking) is not the leading mechanism for these cases of barrel bolt cracking in the analyzed PWRs. (authors)

  12. Determination of rational support parameters of bolting and shotcreting with wire mesh in soft roadway

    Institute of Scientific and Technical Information of China (English)

    LIU She-yu; MA Nian-jie; LIU Shao-wei

    2005-01-01

    Based on a great number of measured data, the author put forward zonal compressive and tensile deformation mechanism of soft rock around roadway. By using self-supporting capacity of compressive zone and controlling rock deformation of tensile zone, the long bolt or short bolt group supporting form was given for different size of rock compressive zone and tensile zone. Finally, studied on the determining method of rational support parameters of bolting and shotcreting with wire mesh in different support technology.

  13. Bolted connections of cold-formed stainless steel at elevated temperatures and post-fire condition

    OpenAIRE

    Cai, Yancheng; 蔡炎城

    2013-01-01

    The structural behaviour of single shear bolted connections and double shear bolted connections of cold-formed stainless steel at elevated temperatures and post-fire condition has been investigated in this study. The current design rules on bolted connections of cold-formed stainless steel are mainly based on those of carbon steel, and are applicable for room (ambient) temperature condition only. These design rules may not be applicable for elevated temperatures. Therefore, design guidelines ...

  14. Ultrasonic Phased Array Techniques for Detection of Flaws of Stud Bolts in Nuclear Power Plants

    International Nuclear Information System (INIS)

    The reactor vessel body and closure head are fastened with the stud bolt that is one of crucial parts for safety of the reactor vessels in nuclear power plants. It is reported that the stud bolt is often experienced by fatigue cracks initiated at threads. Stud bolts are inspected by the ultrasonic technique during the overhaul periodically for the prevention of failure which leads to radioactive leakage from the nuclear reactor. The conventional ultrasonic inspection for stud bolts was mainly conducted by reflected echo method based on shadow effect. However, in this technique, there were numerous spurious signals reflected from every oblique surfaces of the thread. In this study, ultrasonic phased array technique was applied to investigate detectability of flaws in stud bolts and characteristics of ultrasonic images corresponding to different scanning methods, that is, sector and linear scan. For this purpose, simplified stud bolt specimens with artificial defects of various depths were prepared

  15. Development of Automatic Ultrasonic Testing Equipment for Pressure-Retaining Studs and Bolts in Nuclear Power Plant

    International Nuclear Information System (INIS)

    Bolting degradation problems in primary coolant pressure boundary applications have become a major concern in the nuclear industry. In the bolts concerned, the failure mechanism was either corrosion wastage(loss of bolt diameter) or stress-corrosion cracking. Here the manual ultrasonic testing of RPV(Reactor Pressure Vessel) and RCP(Reactor Coolant Pump) stud has been performed. But it is difficult to detect indications because examiner can not exactly control the rotation angle and can not distinguish the indication from signals of bolt. In many cases, the critical sizes of damage depth are very small(1-2 mm order). At critical size, the crack tends to propagatecompletly through the bolt under stress, Resulting in total fracture. Automatic stud scanner for studs(bolts) was developed because the precise measurement of bolt diameter is required in this circumstance. By use of this scanner, the rotation angle of probe was exactly controlled and the exposure time of radiations was reduced

  16. FEM modelling of fatigue loaded bolted flange joints

    Directory of Open Access Journals (Sweden)

    T. Smolnicki

    2007-05-01

    Full Text Available Purpose: The main purpose of this paper is to describe the modelling of large flexible objects in which bolted joints are used and also to present a new FEM calculation methodology of these objects.Design/methodology/approach: In bolted flange joints of flexible constructional elements, bolts are subject not only to tension and torsion but also to bending. Identification of straining of each bolt is only possible by means of numerical methods e.g. the finite element method FEM. In case of large objects, the calculation problem is faithful projection of the phenomena taking place in direct zone of the contact of screw-nut pair. The application of global equivalent models of the whole joint is necessary, to make it possible to precisely determine internal loads in individual bolts and then local models to determine stress fields necessary to assign durability.Calculation methodology based on the construction of two coherent models has been described: global - of an entire flange joint, and local - of a single bolt joint.Findings: The elaborated methodology was applied to estimate the flange joint in the heat exchanger with rotating heating surfaces that was subject to damage. The causes of damage of flange joint were found.Practical implications: Used methodology of FEM modelling of bolted flange joints based on two coherent models may be applied for different similar objects. The paper provides detailed description of methodology steps.Originality/value: The described methodology may be successfully applied to the analysis of large objects, however, significant geometric features with dimensions small in relation to dimensions of the whole object. Thanks to the application of two coherent models, it is possible to reflect all essential phenomena in the FEM model, both in the global scale - of the entire object, and local – a significant fragment of the joint.

  17. Post-Service Examination of PWR Baffle Bolts, Part I. Examination and Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Keith J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sokolov, Mikhail A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gussev, Maxim N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-04-30

    In support of extended service and current operations of the US nuclear reactor plants, the Oak Ridge National Laboratory (ORNL), through the Department of Energy (DOE), Light Water Reactor Sustainability (LWRS) Program, is coordinating with Ginna Nuclear Power Plant, The Westinghouse Electric Company, LLC, and ATI Consulting, the selective procurement of baffle bolts that were withdrawn from service in 2011 and currently stored on site at Ginna. The goal of this program is to perform detailed microstructural and mechanical property characterization of baffle former bolts following in-service exposures. This report outlines the selection criteria of the bolts and the techniques to be used in this study. The bolts available are the original alloy 347 steel fasteners used in holding the baffle plates to the baffle former structures within the lower portion of the pressurized water reactor vessel. Of the eleven possible bolts made available for this work, none were identified to have specific damage. The bolts, however, did show varying levels of breakaway torque required in their removal. The bolts available for this study varied in peak fluence (highest dose within the head of the bolt) between 9.9 and 27.8x1021 n/cm2 (E>1MeV). As no evidence for crack initiation was determined for the available bolts from preliminary visual examination, two bolts with the higher fluence values were selected for further post-irradiation examination. The two bolts showed different breakaway torque levels necessary in their removal. The information from these bolts will be integral to the LWRS program initiatives in evaluating end of life microstructure and properties. Furthermore, valuable data will be obtained that can be incorporated into model predictions of long-term irradiation behavior and compared to results obtained in high flux experimental reactor conditions. The two bolts selected for the ORNL study will be shipped to Westinghouse with bolts of

  18. Rock bolts - Improved design and possibilities

    OpenAIRE

    Thomas-Lepine, Capucine

    2012-01-01

    SummaryRock Bolts, improved design and possibilitiesMaster thesis NTNU 2012Student : Capucine Thomas-LepineSupervisor : Leif LiaKey words : rock foundation, small concrete dam, rock mass classification, rock joints, shear strength of rock discontinuities, fully grouted passive rock bolts designMasters Thesis : “Rock bolts, improved design and possibilities” is a continuation from the Masters Thesis NTNU 2011 “Rock bolts in dams, expected capacity” by Lars Kristian Neby. In...

  19. 49 CFR 236.329 - Bolt lock.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Bolt lock. 236.329 Section 236.329 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... § 236.329 Bolt lock. Bolt lock shall be so maintained that signal governing movements over switch...

  20. EVALUATION OF TROQUE VS CLOSURE BOLT PRELOAD FOR A TYPICAL CONTAINMENT VESSEL UNDER SERVICE CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.

    2010-02-16

    Radioactive material package containment vessels typically employ bolted closures of various configurations. Closure bolts must retain the lid of a package and must maintain required seal loads, while subjected to internal pressure, impact loads and vibration. The need for insuring that the specified preload is achieved in closure bolts for radioactive materials packagings has been a continual subject of concern for both designers and regulatory reviewers. The extensive literature on threaded fasteners provides sound guidance on design and torque specification for closure bolts. The literature also shows the uncertainty associated with use of torque to establish preload is typically between 10 and 35%. These studies have been performed under controlled, laboratory conditions. The ability to insure required preload in normal service is, consequently, an important question. The study described here investigated the relationship between indicated torque and resulting bolt load for a typical radioactive materials package closure using methods available under normal service conditions.

  1. THE MECHANICAL MODEL OF THE FOREPOLING BOLT STRUCTURE FOR STUDYING THE PRE-SUPPORT MECHANISM

    Institute of Scientific and Technical Information of China (English)

    陶龙光; 侯公羽; 乔河

    1995-01-01

    Based on references ,the mechanical models have been developed to study the presupport mechanism of forepoling bolt structure in this paper. The following problems are discussed:(1) the pre-support mechanism of forepoling bolt structure and stress distribution on its upper broken rock! (2) loading state of forepoling bolt; (3) solution of arching in the cross section of excavation。

  2. A study of rock bolting failure modes

    Institute of Scientific and Technical Information of China (English)

    Cao Chen; Jan Nemcik; Ren Ting; Naj Aziz

    2013-01-01

    Rock bolting has advanced rapidly during the past 4 decades due to a better understanding of load transfer mechanisms and advances made in the bolt system technology.Bolts are used as permanent and temporary support systems in tunnelling and mining operations.A review of has indicated that three systems of reinforcement devices have evolved as part of rock bolt and ground anchor while the rock is not generally thought of as being a component of the reinforcement system.A classification of rock bolting reinforcement systems is presented,followed by the fundamental theory of the load transfer mechanism.The failure mode of two phases of rock bolting system is formularised.The failure modes of cable bolting are discussed using a bond strength model as well as an iterative method.Finally,the interfacial shear stress model for ribbed bar is introduced and a closed form solution is obtained using a tri-line stress strain relationship.

  3. The effect of oxidation on the integrity of bolted structures

    International Nuclear Information System (INIS)

    Oxide growing on mild and low alloy steel components in the high pressure CO2 based coolant of the UK gas cooled nuclear power stations can become porous and continue to grow at the interfaces of structural components even when any interfacial gap has filled with oxide. Because such growth gives rise to a net volume expansion, the adjacent components can be forced apart. Any fastening, such as a weld or bolt, holding them together can then become stressed due to growth of oxide alone, and may sustain mechanical damage. The phenomenon is now well understood and methods of predicting behaviour have been developed and refined over the years to ensure safe and continued plant operation. The basis of such methods is presented for bolted joints, and the way in which joint geometry, environment and mechanical properties of component material influence bolt strain is outlined, with examples. (author)

  4. Effects of curing time and frequency on ultrasonic wave velocity in grouted rock bolts

    Science.gov (United States)

    Madenga, V.; Zou, D. H.; Zhang, C.

    2006-05-01

    Grouted rock bolts are widely used to reinforce excavated ground in mining and civil engineering structures. To date, opportunities for testing the quality of the grout in grouted rock bolts have been limited to the pull-out tests and the over-coring methods. Both these methods are destructive, time-consuming and costly. These deficiencies have fueled research into the use of ultrasonic methods for testing the quality of the grout in rock bolts. However, only partial success has been achieved in these efforts chiefly due to inadequate knowledge of the ultrasonic wave characteristics such as wave velocity in grouted rock bolts. This paper presents results of an experimental study into the effects of curing time and testing frequency on the velocity of ultrasonic waves propagating along rock bolts grouted in concrete. A substantial wave velocity decrease, as much as 47.7% at certain frequencies, was recorded in rock bolts grouted in fully cured concrete in comparison to non-grouted bolts. The results demonstrate the importance of optimizing the selection of test frequencies as well as suggesting the possibility of a new approach based on wave velocity decrease for testing the grout quality of rock bolts.

  5. Laboratory evaluation of alloy X-750 clevis bolts removed from D.C. cook unit 1

    International Nuclear Information System (INIS)

    This paper summarizes the results of the laboratory evaluation performed by Babcock and Wilcox on Alloy X-750 clevis bolts removed from the Lower Radial Support System (LRSS) at D.C. Cook Unit 1. A total of 29 clevis bolts - 16 broken and 13 intact - were provided for laboratory analysis and testing to document the extent of degradation, evaluate the integrity of the intact bolts, and identify the bolt degradation/failure mechanism(s). The laboratory work scope included visual and stereo-visual examinations of all bolts. Based on the results of these examinations, four bolts - two broken and two intact - were selected for more detailed analysis/testing, including Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), optical metallography, microhardness, chemical analysis by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS), Rockwell hardness testing, and tensile testing. The laboratory data indicated the bolts failed by intergranular stress corrosion cracking (IGSCC). There was no evidence that the bolts failed due to fatigue cracking or mechanical overload. (authors)

  6. Analysis of alternatives for using cable bolts as primary support at two low-seam coal mines

    Institute of Scientific and Technical Information of China (English)

    Esterhuizen Gabriel S; Tulu Ihsan B

    2016-01-01

    Cable bolts are sometimes used in low-seam coal mines to provide support in difficult ground conditions. This paper describes cable bolting solutions at two low-seam coal mines in similar ground conditions. Both mines used support systems incorporating cable bolts as part of the primary support system. Two original cable bolt based support systems as well as two modified systems are evaluated to estimate their ability to prevent large roof falls. One of the support systems incorporated passive cable bolts, while the other used pre-tensioned cable bolts. The results and experience at the mines showed that the mod-ified systems provided improved stability over the original support systems. The presence of the cable bolts is the most important contribution to stability against large roof falls, rather than the details of the support pattern. It was also found that a heavy steel channel can improve the safety of the system because of the‘sling’ action it provides. Additionally, the analysis showed that fully-grouted rebar bolts load much earlier than the cable bolts, and pre-tensioning of the cable bolts can result in a more uniform distribution of loading in the roof.

  7. Development of signal processing technique for inspection of defects in stud bolts of nuclear reactor vessel

    International Nuclear Information System (INIS)

    Bolt failure is a hazard factor for the safety of reactor vessels in nuclear power plants. However, in the practical application of ultrasonic technique for crack detection in stud bolt, the classification of crack signal from the signals reflected from threads in stud bolt is very difficult. In this study, shadow effect technique combined with new signal processing method has been investigated to enhance the detectability of small crack initiated from root of thread in stud bolt. The key idea of new signal processing concept is based on the fact that the shape of waveforms from the threads is uniform since the shape of the threads in a bolt is same. If some cracks exist in the thread, the flaw signals are different from the reference signals. It has shown that the small flaws can be effectively detected by novel ultrasonic technique combined with this new signal processing concept.

  8. Detection of cracks in stud bolts of nuclear reactor by novel ultrasonic technique

    International Nuclear Information System (INIS)

    The stud bolt is one of the most critical parts for the safety of reactor vessels in nuclear power plants. However, in the practical application of ultrasonic technique for crack detection in stud bolt, the classification of crack signal from the signals reflected from threads in stud bolt is very difficult. In this study, shadow effect technique combined with new signal processing method has been investigated to enhance the detectability of small crack initiated from root of thread in stud bolt. The key idea of new signal processing concept is based on the fact that the shape of waveforms from the threads is uniform since the shape of the threads in a bolt is same. If some cracks exist in the thread, the flaw signals are different from the reference signals. It has shown that the small flaws can be effectively detected by novel ultrasonic technique combined with this new signal processing concept. (orig.)

  9. Enhancement of crack detection in stud bolts of nuclear reactor by ultrasonic signal processing technique

    International Nuclear Information System (INIS)

    'Full-text:' The stud bolts is one of the most critical parts for safety of reactor vessels in the nuclear power plants. However, in the application of ultrasonic technique for crack detection in stud bolt, some difficulties encountered are classification of crack signal from the signals reflected from threads part in stud bolt. In this study, shadow effect technique combined with new signal processing method is Investigated to enhance the detectability of small crack initiated from root of thread in stud bolt. The key idea of signal processing is based on the fact that the shape of waveforms from the threads is uniform since the shape of the threads in a bolt is same. If some cracks exist in the thread, the flaw signals are different to the reference signals. It is demonstrated that the small flaws are efficiently detected by novel ultrasonic technique combined with this new signal processing concept. (author)

  10. Enhancement of crack detection in stud bolts of nuclear reactor by ultrasonic signal processing technique

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.H.; Oh, W.D.; Choi, S.W.; Park, M.H. [Busan National Univ., Busan (Korea, Republic of)

    2004-07-01

    'Full-text:' The stud bolts is one of the most critical parts for safety of reactor vessels in the nuclear power plants. However, in the application of ultrasonic technique for crack detection in stud bolt, some difficulties encountered are classification of crack signal from the signals reflected from threads part in stud bolt. In this study, shadow effect technique combined with new signal processing method is Investigated to enhance the detectability of small crack initiated from root of thread in stud bolt. The key idea of signal processing is based on the fact that the shape of waveforms from the threads is uniform since the shape of the threads in a bolt is same. If some cracks exist in the thread, the flaw signals are different to the reference signals. It is demonstrated that the small flaws are efficiently detected by novel ultrasonic technique combined with this new signal processing concept. (author)

  11. Development of signal processing technique for inspection of defects in stud bolts of nuclear reactor vessel

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Hyun Deok; Lee, Joon Hyun; Choi, Sang Woo; Cho, Youn Ho [Pusan National University, Pusan (Korea, Republic of); Park, Moon Ho [Korea Plant Service and Engineering Co.,Ltd, Sungnam (Korea, Republic of)

    2004-05-15

    Bolt failure is a hazard factor for the safety of reactor vessels in nuclear power plants. However, in the practical application of ultrasonic technique for crack detection in stud bolt, the classification of crack signal from the signals reflected from threads in stud bolt is very difficult. In this study, shadow effect technique combined with new signal processing method has been investigated to enhance the detectability of small crack initiated from root of thread in stud bolt. The key idea of new signal processing concept is based on the fact that the shape of waveforms from the threads is uniform since the shape of the threads in a bolt is same. If some cracks exist in the thread, the flaw signals are different from the reference signals. It has shown that the small flaws can be effectively detected by novel ultrasonic technique combined with this new signal processing concept.

  12. Vibration Characteristic of Anchoring System of Bolt and Elastic Wave Propagation Law

    Institute of Scientific and Technical Information of China (English)

    WANG Cheng; LI Yi; NING Jian-guo; LIN Hua-chang

    2006-01-01

    Based on one-dimension wave theory, the propagation law of elastic wave along the rock bolt, rock medium and their coupling system are researched, and the attenuation law and propagation mechanism of wave in the anchoring system are obtained. Meanwhile, the studies on end reflection and dynamic response under load are also carried out experimentally, the relationship between anchoring length and excited wave length is obtained when the end reflection of bolt emerges, and it is concluded that under the condition of bolt loaded,as the load increases, the reflection of the upper interface of anchoring segment weakens while the end reflection strengthens relatively, hence the energy attenuation increases. These results provide some important theory basis for measuring the effective anchoring length of bolt, judging the bonding quality of anchoring end and surrounding rock, and estimating the utmost load force of bolt.

  13. Failure mechanism of bolting support and high-strength bolt-grouting technology for deep and soft surrounding rock with high stress

    Institute of Scientific and Technical Information of China (English)

    李术才; 王洪涛; 王琦; 江贝; 王富奇; 郭念波; 刘文江; 任尧喜

    2016-01-01

    In deep underground mining, the surrounding rocks are very soft with high stress. Their deformation and destruction are serious, and frequent failures occur on the bolt support. The failure mechanism of bolt support is proposed to solve these problems. A calculation theory is established on the bond strength of the interface between the anchoring agent and surrounding rocks. An analysis is made on the influence law of different mechanical parameters of surrounding rocks on the interfacial bond strength. Based on the research, a new high-strength bolt-grouting technology is developed and applied on site. Besides, some helpful engineering suggestions and measures are proposed. The research shows that the serious deformation and failure, and the lower bond strength are the major factors causing frequent failures of bolt support. So, the bolt could not give full play to its supporting potential. It is also shown that as the integrity, strength, interface dilatancy and stress of surrounding rocks are improved, the bond strength will increase. So, the anchoring force on surrounding rocks can be effectively improved by employing an anchoring agent with high sand content, mechanical anchoring means, or grouting reinforcement. The new technology has advantages in a high strength, imposing pre-tightening force, and giving full play to the bolt supporting potential. Hence, it can improve the control effect on surrounding rocks. All these could be helpful references for the design of bolt support in deep underground mines.

  14. Probabilistic designing of bolted support

    Czech Academy of Sciences Publication Activity Database

    Janas, P.; Krejsa, M.; Šňupárek, Richard; Krejsa, V.

    Praha: Czech Tunelling Association ITA/AITES, 2010 - (Zlámal, J.; Butovič, A.; Hilar, M.), s. 746-752 ISBN 978-80-254-7054-1. [Transport and City Tunnels. Praha (CZ), 14.06.2010-16.06.2010] R&D Projects: GA ČR GA105/07/1265 Institutional research plan: CEZ:AV0Z30860518 Keywords : bolting * probabilistic design * anchoring reinforcement Subject RIV: DH - Mining, incl. Coal Mining

  15. Thermo-mechanical finite element analyses of bolted cask lid structures

    International Nuclear Information System (INIS)

    The analysis of complex bolted cask lid structures under mechanical or thermal accident conditions is important for the evaluation of cask integrity and leak-tightness in package design assessment according to the Transport Regulations or in aircraft crash scenarios. In this context BAM is developing methods based on Finite Elements to calculate the effects of mechanical impacts onto the bolted lid structures as well as effects caused by severe fire scenarios. I n case of fire it might be not enough to perform only a thermal heat transfer analysis. The complex cask design in connection with a severe hypothetical time-temperature-curve representing an accident fire scenario will create a strong transient heating up of the cask body and its lid system. This causes relative displacements between the seals and its counterparts that can be analyzed by a so-called thermo-mechanical calculation. Although it is currently not possible to correlate leakage rates with results from deformation analyses directly an appropriate Finite Element model of the considered type of metallic lid seal has been developed. For the present it is possible to estimate the behaviour of the seal based on the calculated relative displacements at its seating and the behaviour of the lid bolts under the impact load or the temperature field respectively. Except of the lid bolts the geometry of the cask and the mechanical loading is axial-symmetric which simplifies the analysis considerably and a two-dimensional Finite Element model with substitute lid bolts may be used. The substitute bolts are modelled as one-dimensional truss or beam elements. An advanced two-dimensional bolt submodel represents the bolts with plane stress continuum elements. This paper discusses the influence of different bolt modelling on the relative displacements at the seating of the seals. Besides this, the influence of bolt modelling, thermal properties and detail in geometry of the two-dimensional Finite Element models on

  16. Theoretical Calculation and Analysis on the Composite Rock-Bolt Bearing Structure in Burst-Prone Ground

    OpenAIRE

    Liang Cheng; Yidong Zhang; Ming Ji; Mantang Cui; Kai Zhang; Minglei Zhang

    2015-01-01

    Given the increase in mining depth and intensity, tunnel failure as a result of rock burst has become an important issue in the field of mining engineering in China. Based on the Composite Rock-Bolt Bearing Structure, which is formed due to the interaction of the bolts driven into the surrounding rock, this paper analyzes a rock burst prevention mechanism, establishes a mechanical model in burst-prone ground, deduces the strength calculation formula of the Composite Rock-Bolt Bearing Structur...

  17. Experimental Tests and Analytical Models for Welds and Grade 8.8 Bolts under Heating and Subsequent Cooling

    OpenAIRE

    Hanus, François; Zilli, Giuliana; Franssen, Jean-Marc

    2011-01-01

    The present article describes experimental tests performed on bolts and welds at the Centro Sviluppo Materiali under heating and subsequent cooling. Force-displacement laws, calibrated on these tests, are proposed afterwards for bolts in tension, bolts in shear and butt welds in shear during a natural fire. These laws can be integrated into models representing the global behaviour of steel and composite joints, based on the Component Method.

  18. Model-based requirements engineering

    CERN Document Server

    Holt, Jon

    2012-01-01

    This book provides a hands-on introduction to model-based requirementsengineering and management by describing a set of views that form the basisfor the approach. These views take into account each individual requirement interms of its description, but then also provide each requirement with meaning byputting it into the correct 'context'. A requirement that has been put into a contextis known as a 'use case' and may be based upon either stakeholders or levelsof hierarchy in a system. Each use case must then be analysed and validated bydefining a combination of scenarios and formal mathematica

  19. To model bolted parts for tolerance analysis using variational model

    Directory of Open Access Journals (Sweden)

    Wilma Polini

    2015-01-01

    Full Text Available Mechanical products are usually made by assembling many parts. Among the different type of links, bolts are widely used to join the components of an assembly. In a bolting a clearance exists among the bolt and the holes of the parts to join. This clearance has to be modeled in order to define the possible movements agreed to the joined parts. The model of the clearance takes part to the global model that builds the stack-up functions by accumulating the tolerances applied to the assembly components. Then, the stack-up functions are solved to evaluate the influence of the tolerances assigned to the assembly components on the functional requirements of the assembly product. The aim of this work is to model the joining between two parts by a planar contact surface and two bolts inside the model that builds and solves the stack-up functions of the tolerance analysis. It adopts the variational solid model. The proposed model uses the simplified hypothesis that each surface maintains its nominal shape, i.e. the effects of the form errors are neglected. The proposed model has been applied to a case study where the holes have dimensional and positional tolerances in order to demonstrate its effectiveness.

  20. FE-MODELLING OF A CONTACT LAYER BETWEEN ELEMENTS JOINED IN PRELOADED BOLTED CONNECTIONS FOR THE OPERATIONAL CONDITION

    Directory of Open Access Journals (Sweden)

    Rafał Grzejda

    2014-11-01

    Full Text Available Modelling and calculations of a contact layer between elements joined in a preloaded bolted connection for the operational condition are presented. The physical model of the bolted connection is based on a flexible flange element that is joined with a rigid support by means of the no-bolt model (at the assembly stage or the rigid body bolt model (at the operational stage. The contact layer between joined elements is described as the nonlinear Winkler model. The contact joint model considering an experimental normal elastic characteristic is presented. Examples of normal contact pressure and normal contact deformations distributions are contained.

  1. Bolt-Grout Interactions in Elastoplastic Rock Mass Using Coupled FEM-FDM Techniques

    Directory of Open Access Journals (Sweden)

    Debasis Deb

    2010-01-01

    Full Text Available Numerical procedure based on finite element method (FEM and finite difference method (FDM for the analysis of bolt-grout interactions are introduced in this paper. The finite element procedure incorporates elasto-plastic concepts with Hoek and Brown yield criterion and has been applied for rock mass. Bolt-grout interactions are evaluated based on finite difference method and are embedded in the elasto-plastic procedures of FEM. The experimental validation of the proposed FEM-FDM procedures and numerical examples of a bolted tunnel are provided to demonstrate the efficacy of the proposed method for practical applications.

  2. Transcriptomic Analysis Identifies Differentially Expressed Genes (DEGs) Associated with Bolting and Flowering in Radish (Raphanus sativus L.).

    Science.gov (United States)

    Nie, Shanshan; Li, Chao; Wang, Yan; Xu, Liang; Muleke, Everlyne M; Tang, Mingjia; Sun, Xiaochuan; Liu, Liwang

    2016-01-01

    The transition of vegetative growth to bolting and flowering is an important process in the life cycle of plants, which is determined by numerous genes forming an intricate network of bolting and flowering. However, no comprehensive identification and profiling of bolting and flowering-related genes have been carried out in radish. In this study, RNA-Seq technology was applied to analyze the differential gene expressions during the transition from vegetative stage to reproductive stage in radish. A total of 5922 differentially expressed genes (DEGs) including 779 up-regulated and 5143 down-regulated genes were isolated. Functional enrichment analysis suggested that some DEGs were involved in hormone signaling pathways and the transcriptional regulation of bolting and flowering. KEGG-based analysis identified 37 DEGs being involved in phytohormone signaling pathways. Moreover, 95 DEGs related to bolting and flowering were identified and integrated into various flowering pathways. Several critical genes including FT, CO, SOC1, FLC, and LFY were characterized and profiled by RT-qPCR analysis. Correlation analysis indicated that 24 miRNA-DEG pairs were involved in radish bolting and flowering. Finally, a miRNA-DEG-based schematic model of bolting and flowering regulatory network was proposed in radish. These outcomes provided significant insights into genetic control of radish bolting and flowering, and would facilitate unraveling molecular regulatory mechanism underlying bolting and flowering in root vegetable crops. PMID:27252709

  3. Acousto-optic Extensometer for Bolts

    Science.gov (United States)

    Maram, J.; Kuhr, G.

    1985-01-01

    Bolt torque or tension deduced from non contacting measurements. Pulsed Laser induces shockwave in bolthead while continuous-wave acousto-optic detector monitors distortion produced by shock. Shock travel time measured to determine bolt length. Solid-state position detector relatively inexpensive and keeps down cost of extensometer.

  4. 49 CFR 236.756 - Lock, bolt.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Lock, bolt. 236.756 Section 236.756 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.756 Lock, bolt. A mechanical lock so arranged that if a switch, derail or movable-point frog is not in the proper position...

  5. Health monitoring of bolted joints using the time reversal method and piezoelectric transducers

    Science.gov (United States)

    Tao, Wang; Shaopeng, Liu; Junhua, Shao; Yourong, Li

    2016-02-01

    In this paper, the time reversal method based on piezoelectric active sensing is investigated for health monitoring of bolted joints. Experiments are conducted on bolted joints to study the relationship between the time reversal focused signal peak amplitudes and the bolt preload. Two piezoelectric patches are bonded on two different sides of a bolted joint. Any one of the piezoelectric patches can be used as an actuator to generate an ultrasonic wave, and the other one can be used as a sensor to detect the propagated wave. With the time reversal method, the received response signal is reversed in the time domain and then is re-emitted as an excitation signal to acquire the time reversal focused signals. The experimental results show that the time reversal focused signal peak amplitudes increase with the increasing bolt preload until reaching saturation, and when the bolt preload increases to a certain value, the focused signal peak amplitudes will remain unchanged. Experiments show that the surface roughness of the bolted joint impacts the saturation value. A higher surface roughness value corresponds to a higher saturation value. In addition, the proposed method has a high signal to noise ratio benefiting from the time reversal method time and space focusing ability.

  6. Review Paper on Performance Evaluation of Nut and Bolt Recognition System Using Artificial Neural Network

    OpenAIRE

    Shruti Paunikar; Sandeep Shrivastava

    2013-01-01

    There is constant research going on in the field of recognition by means of artificial intelligence to enhance the productivity. The automotive industry requires an automated system to sort different sizes and shapes nut and bolt which are the mainly used component in the industry, to improve the overall productivity. This review paper deals with some feature extraction techniques and its performance impact on the artificial neural network efficiency for the recognition of nut and bolt. The m...

  7. Torque test for bolts/screws in maintaining equipment seismic qualification

    International Nuclear Information System (INIS)

    In an operating nuclear power plant, the original seismic qualification of Class 1E equipment is usually performed by testing the entire enclosure/cabinet with all devices. This paper presents the laboratory torque test results corresponding to snug tight, 1/16 and 1/8 turn past snug tight position for small screws with different materials, mounted using different connection details on thin plates with various thicknesses. The test results compare reasonably well with the theoretical values. Based on the test results, the number of turns past snug tight is recommended for small screws when turn of the nut method is used to control bolt preload and maintain original equipment seismic qualification. It should be noted that for light weight electrical and mechanical assemblies where small bolts/screws require only moderate torque, the snug tight method of applying torque is in general sufficient for all practical purposes. However, for nuclear plants located in high seismic zones, torque beyond snug tight may be required for mounting devices on thin flexible subpanels of cabinets which require seismic qualification

  8. ANCHORING EFFECT ANALYSIS OF TENSIONED BOLTS

    Institute of Scientific and Technical Information of China (English)

    夏建中

    1997-01-01

    The paper analyses quantitatively the anchoring effect of tensioned bolts on surrounding rock strength, and defines two concepts: one is the surrounding rock strength increased amount △τ13 and the other is the strength influence factor k. The anchoring effect of tensioned bolts is considered to increase a strength increased amount △τ13 where △τ13 is the product k and tensioned load p, i. e. △τ13= kp, where k is a function of two variables x and y. The distributive properties both △τ13 and k are also discussed in the paper, obtaining some useful results for designing bolting support parameters.

  9. Analysis profile of the fully grouted rock bolt in jointed rock using analytical and numerical methods

    Institute of Scientific and Technical Information of China (English)

    Ghadimi Mostafa; Shahriar Kourosh; Jalalifar Hossein

    2014-01-01

    The purpose of this study was to investigate the effect of bolt profile on load transfer mechanism of fully grouted bolts in jointed rocks using analytical and numerical methods. Based on the analytical method with development of methods, a new model is presented. To validate the analytical model, five different profiles modeled by ANSYS software. The profile of rock bolts T3 and T4 with load transfer capacity, respectively 180 and 195 kN in the jointed rocks was selected as the optimum profiles. Finally, the selected profiles were examined in Tabas Coal Mine. FLAC analysis indicates that patterns 6+7 with 2NO flexi bolt 4 m better than other patterns within the faulted zone.

  10. Performance evaluation of bolt-cutter system on first Taurus launch

    Science.gov (United States)

    Baban, F.; Williams, R.; Amimoto, S.; Hansen, W.; Bixler, T.

    1994-10-01

    In rapid response to the request of the Space Test and Experimentation Directorate in Space Launch Operations, a launch-critical experimental investigation was conducted to evaluate the performance of a particular bolt-cutter system for separating stages on the first Taurus launch. The tests were to examine the variation of tension preloading on the bolt system and to demonstrate the tolerable margin on this parameter for such launches with the new types of bolts since the preloading was known to vary as much as 12% from a preset value before launch. We planned and carried out the experiment, designed and assembled the fixture to properly simulate flight application, and developed diagnostics. Four bolt cutters were purchased from the manufacturer for these tests, and one was provided by the contractor. In addition to the obvious requirement to demonstrate the successful severing of bolts under varying preloads, ignition-wire current and timing of chisel impact on the bolt were monitored. An optical diagnostic was designed to determine the flyout velocity and kinetic energy of the broken pieces. These latter measurements will be useful in anchoring performance codes simulating and assessing the structural dynamics of the bolt-cutter function for future missions. The tests were conducted successfully and the bolts were severed successfully in all five tests. The preloads were successively lowered from 2,500 lb to 2,250, 2,000, 1,500, and 1,000 lb These tests contributed in a timely manner to the STEP launch decision and to launch mission assurance. They demonstrated important margin to the nominally set 3,200 lb. preload. The entire complicated experimental program from inception to completion was accomplished in less than three weeks.

  11. Safety evaluation for bolting design of a transportable storage canister of spent nuclear fuels

    International Nuclear Information System (INIS)

    This paper is to perform safety evaluation for bolting design of a transportable storage canister of spent nuclear fuels in a nuclear power plant. To develop the related techniques for inter unit transfer of the spent nuclear fuels, a seamless metal canister design with reopening function is adopted. The canister with bolting flange needs to maintain its seamless and structural integrity under normal operation and postulated accident conditions. For bolting design, the requirements on material and structural strength are completely examined by following ASME Boiler and Pressure Vessel Codes. All calculations in this work are performed by using the commercial finite element analysis software, ANSYS. With different sensitivity analysis results of numerical finite element models, the maximum and minimum operation value of bolting preload torque can be thus obtained. Moreover, during the inter unit transfer and operation of spent nuclear fuels, fatigue of the bolt is addressed and no leakage occurs as the canister keeps closure with lids subject to the accident condition is also verified. The structural functions and safety of a transportable storage canister with new bolting design can be shown.

  12. Experimental study and stress analysis of rock bolt anchorage performance

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2014-10-01

    Full Text Available A new method was developed to apply pull-and-shear loads to the bolt specimen in order to evaluate the anchorage performance of the rebar bolt and the D-Bolt. In the tests, five displacing angles (0°, 20°, 40°, 60°, and 90°, two joint gaps (0 mm and 30 mm, and three kinds of host rock materials (weak concrete, strong concrete, and concrete-granite were considered, and stress–strain measurements were conducted. Results show that the ultimate loads of both the D-Bolt and the rebar bolt remained constant with any displacing angles. The ultimate displacement of the D-Bolt changed from 140 mm at the 0° displacing angle (pure pull to approximately 70 mm at a displacing angle greater than 40°. The displacement capacity of the D-Bolt is approximately 3.5 times that of the rebar bolt under pure pull and 50% higher than that of the rebar bolt under pure shear. The compressive stress exists at 50 mm from the bolt head, and the maximum bending moment value rises with the increasing displacing angle. The rebar bolt mobilises greater applied load than the D-Bolt when subjected to the maximum bending. The yielding length (at 0° of the D-Bolt is longer than that of the rebar bolt. The displacement capacity of the bolts increased with the joint gap. The bolt subjected to joint gap effect yields more quickly with greater bending moment and smaller applied load. The displacement capacities of the D-Bolt and the rebar bolt are greater in the weak host rock than that in the hard host rock. In pure shear condition, the ultimate load of the bolts slightly decreases in the hard rock. The yielding speed in the hard rock is higher than that in the weak rock.

  13. Experimental study and stress analysis of rock bolt anchorage performance

    Institute of Scientific and Technical Information of China (English)

    Yu Chen

    2014-01-01

    A new method was developed to apply pull-and-shear loads to the bolt specimen in order to evaluate the anchorage performance of the rebar bolt and the D-Bolt. In the tests, five displacing angles (0?, 20?, 40?, 60?, and 90?), two joint gaps (0 mm and 30 mm), and three kinds of host rock materials (weak concrete, strong concrete, and concrete-granite) were considered, and stressestrain measurements were con-ducted. Results show that the ultimate loads of both the D-Bolt and the rebar bolt remained constant with any displacing angles. The ultimate displacement of the D-Bolt changed from 140 mm at the 0? displacing angle (pure pull) to approximately 70 mm at a displacing angle greater than 40?. The displacement capacity of the D-Bolt is approximately 3.5 times that of the rebar bolt under pure pull and 50%higher than that of the rebar bolt under pure shear. The compressive stress exists at 50 mm from the bolt head, and the maximum bending moment value rises with the increasing displacing angle. The rebar bolt mobilises greater applied load than the D-Bolt when subjected to the maximum bending. The yielding length (at 0?) of the D-Bolt is longer than that of the rebar bolt. The displacement capacity of the bolts increased with the joint gap. The bolt subjected to joint gap effect yields more quickly with greater bending moment and smaller applied load. The displacement capacities of the D-Bolt and the rebar bolt are greater in the weak host rock than that in the hard host rock. In pure shear condition, the ultimate load of the bolts slightly decreases in the hard rock. The yielding speed in the hard rock is higher than that in the weak rock.

  14. Bearing Stresses in Bolted Composite Joints with Different Contact Interactions.

    Directory of Open Access Journals (Sweden)

    Hilton Ahmad

    2016-04-01

    Full Text Available In a bolted joint, it has been shown to be better to model the real contact between bolt and hole than to fix the boundary of the hole edge, a practice used by most previous researchers. Master-slave interaction was implemented in ABAQUS to simulate full contact conditions. Stress distributions were plotted along net-tension plane and hole boundary. Due to geometric non-linearity, the clearance and friction coefficients used substantially effected the maximum stress on hole boundary as shown using the benchmarking work of Eriksson. A physically-based constitutive model used is based on state-of-the art fracture mechanics was used for bolted joint strength prediction. Idealized models from Hollmann were remodelled both by fixing the hole boundary (following the original author and by implementing full contact condition using CZM and XFEM. The physically-based constitutive law used independently measured of unnotched strength and fracture energy parameter for crack opening, which is calibrated from available literatures (known as apparent fracture energy. Good correlation with experimental results was found when using the real contact condition.

  15. Theoretical Calculation and Analysis on the Composite Rock-Bolt Bearing Structure in Burst-Prone Ground

    Directory of Open Access Journals (Sweden)

    Liang Cheng

    2015-01-01

    Full Text Available Given the increase in mining depth and intensity, tunnel failure as a result of rock burst has become an important issue in the field of mining engineering in China. Based on the Composite Rock-Bolt Bearing Structure, which is formed due to the interaction of the bolts driven into the surrounding rock, this paper analyzes a rock burst prevention mechanism, establishes a mechanical model in burst-prone ground, deduces the strength calculation formula of the Composite Rock-Bolt Bearing Structure in burst-prone ground, and confirms the rock burst prevention criterion of the Composite Rock-Bolt Bearing Structure. According to the rock burst prevention criterion, the amount of the influence on rock burst prevention ability from the surrounding rock parameters and bolt support parameters is discussed.

  16. FEM analyses of stress and deformation of a flexible inner pressure bolt

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhong-he; WANG Wei-qiang; ZHANG Le-wen

    2008-01-01

    The flexible inner pressure bolt is a new kind and new structural bolt (anchor rod). A number of structural improvements and performance test have been carried out. The bolt has superior compatibility to the soft crag and the large distortion tunnel with its flexibility. In order to study its stress, deformation and interaction mechanism thoroughly, a number of large distortion calculations and analyses have been carried out on the bolt by FEM (finite element method), especially with the ANSYS software, based on the updated Lagrangian law. The results show that the maximum stress of the inner wall of the bolt is consistent with an elastic analytic solution. The maximum stress on the body occurs in the vicinity of the enhancement material. The link enhancement of the body seems to be quite essential. The experimental results indicate that the maximum injection pressure in the bolt is 2.5 MPa without link enhancement and 8.3 MPa with the enhancement. This link enhancement effect is highly significant. These results provide some basis for the design, application and anchoring stress analysis of the holt.

  17. A Noble Approach of Process Automation in Galvanized Nut, Bolt Manufacturing Industry

    Directory of Open Access Journals (Sweden)

    Akash Samanta

    2012-05-01

    Full Text Available Corrosion costs money”, The Columbus battle institute estimates that corrosion costs Americans more than $ 220 billion annually, about 4.3% of the gross natural product [1].Now a days due to increase of pollution, the rate of corrosion is also increasing day-by-day mainly in India, so, to save the steel structures, galvanizing is the best and the simplest solution. Due to this reason galvanizing industries are increasing day-by-day since mid of 1700s.Galvanizing is a controlled metallurgical combination of zinc and steel that can provide a corrosion resistance in a wide variety of environment. In fact, the galvanized metal corrosion resistance factor can be some 70 to 80 times greater that the base metal material. Keeping in mind the importance of this industry, a noble approach of process automation in galvanized nut-bolt  manufacturing plant is presented here as nuts and bolts are the prime ingredient of any structure. In this paper the main objectives of any industry like survival, profit maximization, profit satisfying and sales growth are fulfilled. Furthermore the environmental aspects i.e. pollution control and energy saving are also considered in this paper. The whole automation process is done using programmable logic controller (PLC which has number of unique advantages like being faster, reliable, requires less maintenance and reprogrammable. The whole system has been designed and tested using GE, FANUC PLC.

  18. Performance of D-bolts Under Static Loading

    Science.gov (United States)

    Li, Charlie C.

    2012-03-01

    D-bolt is a type of energy-absorbing rock bolt. It is made of a smooth steel bar with anchors spaced along the bolt length. A typical section between adjacent anchors is approximately 1-m long, but it can be adjusted to adapt to the rock conditions. The bolt is fully encapsulated with either cement or resin grout in a borehole. The anchors are firmly fixed into the grout, while the smooth bolt sections can freely deform to absorb deformation energy. Full-scale static pull tests were carried out at different testing facilities in two laboratories. The tests show that a smooth bolt section between anchors may elongate by 110-167 mm depending on the section length. Field trials of the D-bolt were conducted in deep metal mines. The measurements showed that the D-bolts were equally loaded within every anchor-between section, avoiding load peaks and premature bolt failure due to stress concentrations caused by fracture/joint opening. The field trials of rebar and D-bolts in a largely deformed mine tunnel showed that the D-bolts behaved satisfactorily, with only a few failed bolts, while a number of the rebar bolts failed at the thread.

  19. More Nuts and Bolts of Michaelis-Menten Enzyme Kinetics

    Science.gov (United States)

    Lechner, Joseph H.

    2011-01-01

    Several additions to a classroom activity are proposed in which an "enzyme" (the student) converts "substrates" (nut-bolt assemblies) into "products" (separated nuts and bolts) by unscrewing them. (Contains 1 table.)

  20. Rock bolt mechanical analysis and its application to engineering

    Institute of Scientific and Technical Information of China (English)

    GUO Ling-yun; XIAO Ming; XIAO Ying-chun

    2008-01-01

    Combined with the 3D FEM, end-anchored anchorage bolts were simulated by implicit anchorage bolt element. Implicit anchorage bolt elements hide in the elements of rock mass and extremely simplify the element subdivision. The calculated value of an-chorage bolt stress is larger than the measured one for the most time. we further analyzed the reciprocity of anchorage bolt and rock mass, and then deduced the analytical equa-tions of anchorage bolt stress and rock mass deformation under elasto-plastic state. The results indicate that it is essential to revise the anchorage bolts stress by using the formu-las deduced when rock mass is softened or significantly deformed. Finally, a case study indicates that the calculated results agree with those measured. Some helpful methods are offerd for more accurate simulation of the support effect and anchorage bolts real stress state.

  1. Tension-loaded bolted connections in steel structures

    OpenAIRE

    Skavhaug, Elin Stensrud; Østhus, Svanhild Irene

    2015-01-01

    The purpose of this thesis is to study the behaviour of bolted steel connections subjected to tension. Quasi-static conditions have been considered. By performing laboratory tests on single bolts and simple T-stub connections the failure modes of the bolts have been examined. Finite element models are created and validated to represent the behaviour observed in the laboratory. Different grip length configurations have been tested for a single bolt and nut assembly subjected to pure tensio...

  2. On prestress stiffness analysis of bolt-plate contact assemblies

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Pedersen, Pauli

    2008-01-01

    Bolt connections are among the most important connections used in structures. The stiffnesses of the bolt and of the connected members are the primary qualities that control the lifetime of the connection. The stiffness of the bolt can be estimated rather easily, in contrast to the member stiffness...

  3. Parametric study on the axial performance of a fully grouted cable bolt with a new pull-out test

    Institute of Scientific and Technical Information of China (English)

    Chen Jianhang⇑; Hagan Paul C.; Saydam Serkan

    2016-01-01

    Modified cable bolts are commonly used in underground mines due to their superior performance in pre-venting bed separation when compared with plain strands. To better test the axial performance of a wide range of cable bolts, a new laboratory short encapsulation pull test (LSEPT) facility was developed. The facility simulates the interaction between cable bolts and surrounding rock mass, using artificial rock cylinders with a diameter of 300 mm in which the cable bolt is grouted. Furthermore, the joint where the load is applied is left unconstrained to allow shear slippage at the cable/grout or grout/rock interface. Based on this apparatus, a series of pull tests were undertaken using the MW9 modified bulb cable bolt. Various parameters including embedment length, test material strength and borehole size were evalu-ated. It was found that within a limited range of 360 mm, there is a linear relationship between the max-imum bearing capacity of the cable bolt and embedment length. Beyond 360 mm, the peak capacity continues to rise but with a much lower slope. When the MW9 cable bolt was grouted in a weak test material, failure always took place along the grout/rock interface. Interestingly, increasing the borehole diameter from 42 to 52 m in weak test material altered the failure mode from grout/rock interface to cable/grout interface and improved the performance in terms of both peak and residual capacity.

  4. Review Paper on Performance Evaluation of Nut and Bolt Recognition System Using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Shruti Paunikar

    2013-09-01

    Full Text Available There is constant research going on in the field of recognition by means of artificial intelligence to enhance the productivity. The automotive industry requires an automated system to sort different sizes and shapes nut and bolt which are the mainly used component in the industry, to improve the overall productivity. This review paper deals with some feature extraction techniques and its performance impact on the artificial neural network efficiency for the recognition of nut and bolt. The main feature extraction techniques analysed for this review paper are stationary wavelet transform, principle component analysis and radius analysis. The aforementioned techniques are already tested and simulation is done on MATLAB.The results obtained varies depending on pre-processing techniques used for the nut and bolt recognition.

  5. Monitoring of bolted joints using piezoelectric active-sensing for aerospace applications

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gyuhae [Los Alamos National Laboratory; Farrar, Charles R [Los Alamos National Laboratory; Park, Chan - Yik [ADD; Jun, Seung - Moon [ADD

    2010-01-01

    This paper is a report of an initial investigation into tracking and monitoring the integrity of bolted joints using piezoelectric active-sensors. The target application of this study is a fitting lug assembly of unmanned aerial vehicles (UAVs), where a composite wing is mounted to a UAV fuselage. The SHM methods deployed in this study are impedance-based SHM techniques, time-series analysis, and high-frequency response functions measured by piezoelectric active-sensors. Different types of simulated damage are introduced into the structure, and the capability of each technique is examined and compared. Additional considerations encountered in this initial investigation are made to guide further thorough research required for the successful field deployment of this technology.

  6. Numerical simulation of the effect of coupling support of bolt-mesh-anchor in deep tunnel

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-ming; CAI Feng; YANG Jun; CAO Wu-fu

    2009-01-01

    The mechanical effects of bolt-mesh-anchor coupling support in deep tunnels were studied by using a numerical method, based on deep tunnel coupling supporting techniques and non-linear deformation mechanical theory of rock mass at great depths. It is shown that the potential of a rigid bolt support can be efficiently activated through the coupling effect between a bolt-net support and the surrounding rock. It is found that the accumulated plastic energy in the surrounding rock can be sufficiently transformed by the coupling effect of a bolt-mesh-tray support. The strength of the surrounding rock mass can be mobilized to control the deformation of the surrounding rock by a pre-stress and time-space effect of the anchor support. The high stress transformation effect can be realized by the mechanical coupling effect of the bolt-mesh-anchor support, whereby the force of the support and deformation of the surrounding rock tends to become uniform, leading to a sustained stability of the tunnel.

  7. Shear fracture of jointed steel plates of bolted joints under impact load

    Science.gov (United States)

    Daimaruya, M.; Fujiki, H.; Ambarita, H.; Kobayashi, H.; Shin, H.-S.

    2013-07-01

    The present study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of bolted joints used in a car body, which contributes to crash simulations by CAE. We focus our attention on the shear fracture of the jointed steel plates of lap-bolted joints in the suspension of a car under impact load. Members of lap-bolted joints are modelled as a pair of steel plates connected by a bolt. One of the plates is a specimen subjected to plastic deformation and fracture and the other is a jig subjected to elastic deformation only. Three kinds of steel plate specimens are examined, i.e., a common steel plate with a tensile strength of 270 MPa and high tensile strength steel plates of 440 and 590 MPa used for cars. The impact shear test was performed using the split Hopkinson bar technique for tension impact, together with the static test using a universal testing machine INSTRON 5586. The behaviour of the shear stress and deformation up to rupture taking place in the joint was discussed. The obtained results suggest that a stress-based fracture criterion may be developed for the impact fracture of jointed steel plates of a lap-bolted joint.

  8. Shear fracture of jointed steel plates of bolted joints under impact load

    International Nuclear Information System (INIS)

    The present study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of bolted joints used in a car body, which contributes to crash simulations by CAE. We focus our attention on the shear fracture of the jointed steel plates of lap-bolted joints in the suspension of a car under impact load. Members of lap-bolted joints are modelled as a pair of steel plates connected by a bolt. One of the plates is a specimen subjected to plastic deformation and fracture and the other is a jig subjected to elastic deformation only. Three kinds of steel plate specimens are examined, i.e., a common steel plate with a tensile strength of 270 MPa and high tensile strength steel plates of 440 and 590 MPa used for cars. The impact shear test was performed using the split Hopkinson bar technique for tension impact, together with the static test using a universal testing machine INSTRON 5586. The behaviour of the shear stress and deformation up to rupture taking place in the joint was discussed. The obtained results suggest that a stress-based fracture criterion may be developed for the impact fracture of jointed steel plates of a lap-bolted joint

  9. Stud-bolts strength for cell-liner design under shearing deformation

    International Nuclear Information System (INIS)

    This paper presents experimental and analytical stud-bolt strength subjected to large shearing deformation at high temperature. Tensile test result of the material, SM41B, was shown in the range of room temperature to 550degC at 10-3 and 10-4 m/m/s in strain rate. Shearing fracture test result of the stud-bolt is shown at room temperature and 530degC. Shearing fracture criterion was discussed based on both test results and FEM analysis result. (author)

  10. Behaviour of high stretch bolts in tension working as part of elements of steel structures, and their tendency to delayed fracturing

    Directory of Open Access Journals (Sweden)

    Moyseychik Evgeniy Alekseevich

    2014-12-01

    Full Text Available In the article, the author has proven that manufacturing and installation errors, as well as contact deformations of high strength bolts, if analyzed as part of tensile connections of steel structures, work in eccentric tension. In pursuance of the effective state standards, the analysis of these bolts is based on the axial tension. The author has analyzed the failure of a steel structure, caused by the fracture of eccentrically loaded bolts made of steel grade XC 42 (France, or C40 (Germany, that later followed the delayed fracturing pattern. The author provides the findings of the lab tests, whereby the above bolts were tested in the presence of an angle washer. The author has also analyzed the findings of low-temperature tests of bolts in tension. The author demonstrates that the strength of high strength bolts is driven by the material, the structure shape, and the thermal treatment pattern. Eccentric tension tests of bolts have proven that cracks emerge in the areas of maximal concentration of stresses (holes in shafts, etc. that coincide with the areas where fibers are in tension; cracks tend to follow the delayed fracturing pattern, and their development is accompanied by the deformation-induced metal heating in the fracture area. Therefore, the analysis of high strength bolts shall concentrate on the eccentric tension with account for contact-induced loads, while the tendency to delayed fracturing may be adjusted through the employment of both metallurgical and process techniques.

  11. Discussion on Wind Turbine Bolt Connection Design%风力发电机组高强螺栓连接设计的探讨

    Institute of Scientific and Technical Information of China (English)

    刘洪海; 于春来

    2012-01-01

    本文根据风力发电机组运行特点,从多个角度介绍了风力发电机组高强螺栓连接设计时需要注意的问题.介绍了风力发电机组中高强螺栓连接类型、螺栓连接类型的选择、改善螺栓受力的措施、拧入机体螺栓最小拧入深度的确定、螺栓连接防松方法的选择.通过风电实例,对螺栓连接设计进行了探讨,对风电机组设计有借鉴和启发意义.%Based on the operational features of the wind turbine, wind turbine bolt connection design was presented from multiple perspectives. Bolt connection types, how to properly choose the type of bolt connection, measures to improve the bolt force, screwed into the determination of the minimum depth of the body bolts, bolted locking method selection were presented. By the wind turbine bolt connection design instance, bolt connection design was discussed, which had reference and inspiration to wind turbine design.

  12. Remote controlled stud bolt handling device for reactor pressure vessel

    International Nuclear Information System (INIS)

    In nuclear power stations, at the time of regular inspection, the works of opening and fixing the upper covers of reactor pressure vessels are carried out for inspecting the inside of reactor pressure vessels and exchanging fuel rods. These upper covers are fastened with many stud bolts, therefore, the works of opening and fixing require a large amount of labor, and are done under the restricted condition of wearing protective clothings and masks. Babcock Hitachi K.K. has completed the development of a remotely controlled automatic bolt tightenig device for this purpose, therefore, its outline is reported. The conventional method of these works and the problems in it are described. The design of the new device aimed at the parallel execution of cleaning screw threads, loosening and tightening nuts, and taking off and putting on nuts and washers, thus contributing to the shortening of regular inspection period, the reduction of the radiation exposure of workers, and the decrease of the number of workers. The function, reliability and endurance of the new device were confirmed by the verifying test using a device made for trial. The device is composed of a stand, a rail and four stations each with a cleaning unit, a stud tensioner and a nut handling unit. (K.I.)

  13. Optimization of bolt thread stress concentrations

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    Designs of threaded fasteners are controlled by different standards, and the number of different thread definitions is large. The most commonly used thread is probably the metric ISO thread, and this design is therefore used in the present paper. Thread root design controls the stress concentration...... factor of threads and therefore indirectly the bolt fatigue life. The root shape is circular, and from shape optimization for minimum stress concentration it is well known that the circular shape is seldom optimal. An axisymmetric Finite Element formulation is used to analyze the bolted connection, and a...... study is performed to establish the need for contact modeling with regard to finding the correct stress concentration factor. Optimization is performed with a simple parameterization with two design variables. Stress reduction of up to 9% is found in the optimization process, and some similarities are...

  14. Stiffness Analysis and Improvement of Bolt-Plate Contact Assemblies

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Pedersen, Pauli

    2008-01-01

    In a previous study it was shown that, a simplified expression for the stiffness of the plate member in a bolt-plate assembly can be found. The stiffnesses of the bolt and the connected plates are the primary quantities that control the lifetime of a dynamically loaded connection. The present study...... of stiffnesses is extended to include different material parameters by including the influence of Poisson's ratio. Two simple practical formulas are suggested and their accuracies are documented for different bolts and different material (Poisson's ratio). Secondly, the contact analysis between the...... bolt head and the plate is extended by the possibility of designing a gap, that is, a nonuniform distance between the bolt and plate before prestressing. Designing the gap function generates the possibility for a better stress field by which the stiffness of the bolt is lowered, and at the same time...

  15. Apparatus for the ultrasonic examination of shroud hold down bolts

    International Nuclear Information System (INIS)

    A process of testing hold down bolts depending from the sides of a steam separator within a nuclear reactor is described the process comprising the steps of: maintaining the steam separator under water; moving the bolts to unlatch the bolts from brackets on the shroud adjacent the steam separator; providing a shoe having a piezoelectric device mounted to the bottom of the shoe and exposed upwardly; providing a remotely actuated clamp attached to the shoe overlying the piezoelectric device; providing a mount to the shoe for manipulating the shoe underwater in a depending relationship at the bottom end of a pole; providing a pole and attaching the pole to the shoe; manipulating the shoe to the bottom of the bolt; and clamping the shoe to the bolt; and testing the bolt with the piezoelectric device

  16. Beware of Nuts and Bolts: Putting Evolution into the Teaching of Biological Classification

    Science.gov (United States)

    Nickels, Martin K.; Nelson, Craig E.

    2005-01-01

    Biological classification embodies the most fundamental idea in all of biology, especially evolution. The contrast between biological classifications and those of manufactured objects for instance hardware-based collection of screws, nails and bolts, help illustrate the central biological ideas and induce student interest, however, this could be…

  17. Experimental study of friction in aluminium bolted joints

    OpenAIRE

    Vincenzi N.; De Agostinis M.; Croccolo D.

    2010-01-01

    This study aims at developing an experimental tool useful to define accurately the friction coefficients in bolted joints and, therefore, at relating precisely the tightening torque to the bolt preloading force in some special components used in front motorbike suspensions. The components under investigation are some clamped joints made of aluminium alloy. The preloading force is achieved by applying a torque wrench to the bolt head. Some specific specimens have been appropriately desig...

  18. Twofold hidden conformal symmetry of Kerr Bolt black holes

    International Nuclear Information System (INIS)

    Previously we have shown that a four-dimensional Kerr—Bolt black hole in non-extremal and also in extremal cases could be described by a holographic two-dimensional (2D) conformal field theory (CFT) [Ghezelbash A M, Kamali V and Setare M R 2010 Phys. Rev. D 82 124051; Setare M R and Kamali V 2010 JHEP 10 074]. Motivated by recent work [Chen C M, Huang Y M, Sun J R, Wu M F and Zou S J 2010 Phys. Rev. D 82 066004], we show that there is another holographic description for these black holes. The first description is called the J-picture, whose construction is based on the black hole angular momentum. The new description is called the Q-picture, whose constructions originate from the nut charge of the black hole. Similar to the previous cases [Ghezelbash A M, Kamali V and Setare M R 2010 Phys. Rev. D 82 124051; Setare M R and Kamali V 2010 JHEP 10 074], we show that this new picture for a low frequency limit of the wave equation of a massless charged scalar field in the background of a Kerr—Bolt black hole can be written as the Casimir of SL(2, R) symmetry. Our result shows that the entropy of the black hole is reproduced by the Cardy formula. In addition, the absorption cross section is consistent with the finite temperature absorption cross section for a two-dimensional CFT. (general)

  19. Requirements engineering-based conceptual modeling

    OpenAIRE

    Insfrán, E.; O. Pastor; Wieringa, R.J.

    2002-01-01

    The software production process involves a set of phases where a clear relationship and smooth transitions between them should be introduced. In this paper, a requirements engineering-based conceptual modelling approach is introduced as a way to improve the quality of the software production process. The aim of this approach is to provide a set of techniques and methods to capture software requirements and to provide a way to move from requirements to a conceptual schema in a traceable way. T...

  20. High strength bolt failure analysis and integrity assessment. Lessons learned

    International Nuclear Information System (INIS)

    Isolated failures have occurred in high strength bolting used in pressurized water reactor (PWR) component support applications. The U.S. nuclear industry component support bolting failure experience is described in this paper, focusing on materials specified intentionally as ''ultra-high-strength'' (minimum specified yield strength greater than 1034 MPa). The analysis and investigation of fabrication-induced problems with a bolt made from Carpenter Technology Alloy ''Custom 455'', (ASTM A 564 XM-16) a proprietary materials, are detailed, and the measures taken to assure integrity of these bolts during operation are discussed. Lessons learned to preclude future problems are presented as conclusions

  1. Velocity dispersions in a cluster of stars: How fast could Usain Bolt have run?

    CERN Document Server

    Eriksen, H K; Langangen, O; Wehus, I K

    2008-01-01

    Since that very memorable day at the Beijing 2008 Olympics, a big question on every sports commentator's mind has been "What would the 100 meter dash world record have been, had Usain Bolt not celebrated at the end of his race?" Glen Mills, Bolt's coach suggested at a recent press conference that the time could have been 9.52 seconds or better. We revisit this question by measuring Bolt's position as a function of time using footage of the run, and then extrapolate into the last two seconds based on two different assumptions. First, we conservatively assume that Bolt could have maintained Richard Thompson's, the runner-up, acceleration during the end of the race. Second, based on the race development prior to the celebration, we assume that he could also have kept an acceleration of 0.5 m/s^2 higher than Thompson. In these two cases, we find that the new world record would have been 9.61 +/- 0.04 and 9.55 +/- 0.04 seconds, respectively, where the uncertainties denote 95% statistical errors.

  2. Design versus manufacturing data base management requirements

    Science.gov (United States)

    Mckenna, E. G.

    1984-01-01

    Data base management systems are valuable manufacturing and design tools as these disciplines are exceptionally information intensive, requiring precise organization and control of data processing and utilization. One such data base manager is the IPAD* system, which was originally developed to support the design process but was expanded to incorporate the additional needs of manufacturing. To set the stage, an overview of the design and manufacturing process is presented. The different functions of computers in these processes are then discussed. Finally, the design and manufacturing requirements for a data base manager are compared and contrasted.

  3. A marketing plan for Lightning Bolt

    OpenAIRE

    Silveira, Filipa Borges

    2013-01-01

    This project had as main goal to improve the perception of male surfers about the surf brand Lightning Bolt. It was proposed the creation of a collection of wetsuits as well as the “A Pure Source” Project to show the commitment of the brand with the surf community. To promote both several promotional activities are suggested such as the use of magazines, radio, banners and social media. To complement the distribution chain of the brand, a concept store and a mobile store are also recommended....

  4. Impact extractive fracture of jointed steel plates of a bolted joint

    Directory of Open Access Journals (Sweden)

    Ambarita H.

    2012-08-01

    Full Text Available This study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of a bolted joint used in a car body. For the accurate prediction of crash characteristics of car bodies by computer-aided engineering (CAE, it is also necessary to examine the behavior and fracture of jointed steel plates subjected to impact loads. Although the actual impact fracture of jointed steel plates of a bolted joint used in cars is complicated, for simplifying the problem it might be classified into the shear fracture and the extractive fracture of jointed steel plates. Attention is given to the extractive fracture of jointed steel plates in this study. The extractive behavior and fracture of three kinds of steel plates used for cars are examined in experiments and numerical simulations. The impact extraction test of steel plates jointed by a bolt is performed using the one-bar method, together with the static test. In order to understand the mechanism of extractive fracture process of jointed steel plates, numerical simulations by a FEM code LS-DYNA are also carried out. The obtained results suggest that a stress-based fracture criterion may be developed for the impact extractive fracture of jointed steel plates of a bolted joint used in a car body.

  5. Numerical simulation of creep characteristics of soft roadway with bolt-grouting support

    Institute of Scientific and Technical Information of China (English)

    王连国; 李海亮; 张健

    2008-01-01

    Based on the engineering background of a soft rock roadway in Qinan Coal Mine 82 Area,Huaibei Mining Group,three creep models with different support patterns in soft rock roadway were established by using geotechnical software of FLAC2D.According to the calculation results of different models,the change law of mechanical properties with the time of bolt-grouting support structure was obtained.Furthermore,for the test bolt-grouting support roadway,the deformation law of surrounding rock got by underground industrial experiment and field observation accords with the creep law got by numerical calculation.The results of numerical calculation and field observation show that,compared with other supports,the creep of bolt-grouting support roadway enters the steady-state creep stage from tertiary creep stage ahead,the deformations of roof,floor and two sides are decreased greatly,the plastically deforming area in surrounding rock is reduced obviously,and the distribution ranges of maximum and minimum principal stress are shrank obviously.All those fully show that the bolt-grouting support has its remarkable advantages in controlling surrounding rock creep and improving the whole strength of surrounding rock and self-bearing capacity.

  6. Loosening and Sliding Behaviour of Bolt-Nut Fastener under Transverse Loading

    Directory of Open Access Journals (Sweden)

    Naruse T.

    2010-06-01

    Full Text Available The thread joint has been frequently used for the efficient productivity and maintainability as a machine element. However, many troubles such as loosening of bolted joints or fatigue failure of bolt were often experienced. Many attentions must be paid on the improvement of the strength and the reliability of the thread joints [1, 2]. It is generally said that the fastening axial force rapidly decreases by the rotation loosening of nuts if the relative slippage on the interfaces between nuts and fastened body goes beyond a certain critical limit [3]. This critical relative slippage (Scr that prescribes the upper limit for preventing the loosening behaviour has been estimated according to the theoretically obtained equation considering the bending deformation of bolt and the geometrical constraint condition. In this paper, firstly we present the equation for estimating the Scr based on the fundamental cantilever deformation model. Then we present the investigated results of the deformation behaviour of bolt-nut joint under transverse loading condition considering the reaction moment by nut (Mn. Finaly we can confirmed that these estimated results of critical relative slippage coincided well with the experimental results [4, 5].

  7. Structural analysis of closure bolts for shipping casks

    Energy Technology Data Exchange (ETDEWEB)

    Mok, G.C.; Fischer, L.E.

    1993-04-01

    This paper identifies the active forces and moments in a closure bolt of a shipping cask. It examines the interactions of these forces/moments and suggest simplified methods for their analysis. The paper also evaluates the role that the forces and moments play in the structure integrity of the closure bolt and recommends stress limits and desirable practices to ensure its integrity.

  8. Accuracy of tunnelated vs. bolt-connected external ventricular drains

    DEFF Research Database (Denmark)

    Bergdal, Ove; Springborg, Jacob Bertram; Holst, Anders Vedel;

    2013-01-01

    40%. As an alternative to the tunnelated EVD technique we often use a bolt-connected EVD. The aim of the present study was to investigate whether the use of bolt-connected EVDs would lead to higher accuracy, fewer passes and reoperations due to poor placement compared to tunnelated EVDs....

  9. The effects of bolted joints on dynamic response of structures

    International Nuclear Information System (INIS)

    Joint is an universal fastening technology for structural members; in particular bolted joints are extensively used in mechanical structures due to their simple maintenance and low cost. However, the components of bolted joints are imperative because failure could be catastrophic and endanger lives. Hence, in this study, the effects of bolted joints on vibrating structures are investigated by determining the structural dynamic properties, such as mode shapes, damping ratios and natural frequencies, and these are compared with the monolithic structures (welding). Two approaches of experimental rigs are developed: a beam and a frame where both are subjected to dynamic loading. The analysis reveals the importance of bolted joints in increasing the damping properties and minimizing the vibration magnitude of structures, this indicates the significant influence of bolted joints on the dynamic behaviour of assembled structures. The outcome of this study provides a good model for predicting the experimental variable response in different types of structural joints

  10. Application of shape memory alloys in bolted flanged connections

    International Nuclear Information System (INIS)

    The Shape Memory Effect (SME) and super elasticity of the Shape Memory Alloys (SMA) can make up the clamping force decreasing caused by the creep and relaxation behavior in Bolted Flanged Connections (BFC), and improve the reliability of the BFC. Advances in the research of SMA in BFC home and abroad is summarized in this paper. The application prospects of Ti-Ni-Pd, Ti-Ni-Hf, Fe-Mn-Si, Cu-Al-Ni and Ni-Al-Mn in the BFC are also discussed. It is considered that the compressive characteristics of the parent phase of SMA should be studied further for the application of SMA to BFC besides the design of sealing structure. When more basic research data is accumulated, BFC with high sealing performance for the critical engineering applications can be developed based on the comprehensive consideration of the stability and reliability of the clamping force. (authors)

  11. Bolted flanged connections with longitudinal bending moments: Experimental results

    International Nuclear Information System (INIS)

    Flanges in piping systems and on tall vertical pressure vessels such as columns or fractionators, are often subjected to external, longitudinal bending moments of considerable magnitude. In piping systems, such bending moments are usually caused by thermal expansion. On pressure vessel flanges, external bending moments are often the result of wind or seismic loadings. In the ASME Code, only Section III, the Nuclear Power Plant Code, Subsections NB, NC, and ND, contain design rules for external bending moments on flanges. In Subsections NB, NC, and ND, an empirical formula is given, expressing a longitudinal bending moment in bolted flanged connections in terms of an equivalent internal pressure to be added to the design pressure of the flange. Other sections of the ASME Code, in particular Section VIII, Divisions 1 and 2, also the ASME-ANSI Piping Codes, do not contain rules for such external, longitudinal bending moments. In previous papers by the same authors, it was shown that a single empirical expression to convert external bending moments to intemal pressure, cannot include the differences between the geometries of flanges of various sizes. An attempt was also made to analyse the stresses in the flange-bolt assembly due to extemal bending moments and to compare flange thicknesses thus obtained with thicknesses required using the equivalent design pressure, specified in Subsections NB, NC, and ND. The present paper reports the findings of a series of experiments on a pair of 100 mm, Class 10 (4 inch, Class 150) pipe flanges which were subjected to various combinations of intemal pressure and extemal longitudinal bending. Measured values are compared with a proposed analytic design method and with results using the empirical formula of the ASME Code, Section III

  12. Tool-based requirement traceability between requirement and design artifacts

    CERN Document Server

    Turban, Bernhard

    2013-01-01

    Processes for developing safety-critical systems impose special demands on ensuring requirements traceability. Achieving valuable traceability information, however, is especially difficult concerning the transition from requirements to design. Bernhard Turban analyzes systems and software engineering theories cross-cutting the issue (embedded systems development, systems engineering, software engineering, requirements engineering and management, design theory and processes for safety-critical systems). As a solution, the author proposes a new tool approach to support designers in their thinkin

  13. Twofold hidden conformal symmetry of Kerr-Bolt black holes

    Institute of Scientific and Technical Information of China (English)

    M.R. Setare; V. Kamali

    2012-01-01

    Previously we have shown that a four-dimensional Kerr-Bolt black hole in non-extremal and also in extremal cases could be described by a holographic two-dimensional (2D) conformal field theory (CFT) [Ghezelbash A M,Kamali V and Setare M R 2010 Phys.Rev.D 82 124051; Setare M R and Kamali V 2010 JHEP 10 074].Motivated by recent work [Chen C M,Huang Y M,Sun J R,Wu M F and Zou S J 2010 Phys.Rev.D 82 066004],we show that there is another holographic description for these black holes.The first description is called the J-picture,whose construction is based on the black hole angular momentum.The new description is called the Q-picture,whose constructions originate from the nut charge of the black hole.Similar to the previous cases [Ghezelbash A M,Kamali V and Setare M R 2010 Phys.Rev.D 82 124051; Setare M R and Kamali V 2010 JHEP 10 074],we show that this new picture for a low frequency limit of the wave equation of a massless charged scalar field in the background of a Kerr-Bolt black hole can be written as the Casimir of SL(2,R) symmetry.Our result shows that the entropy of the black hole is reproduced by the Cardy formula.In addition,the absorption cross section is consistent with the finite temperature absorption cross section for a two-dimensional CFT.

  14. Fretting fatigue mechanism of bearing cap bolted joints

    Science.gov (United States)

    Li, Xin; Zuo, Zhengxing; Qin, Wenjie

    2014-05-01

    Fretting fatigue is a common type of failure of the bearing cap bolted joints. This paper proposes a methodology to analyze the fretting fatigue mechanism of the bearing cap bolted joint. A biaxially loading system was designed to simulate fretting fatigue failure under typical engine working condition. Meanwhile, a submodel was developed in the finite element calculation to analyze the contact status and stress distribution of the structural models. The test result shows that long inclined cracks (about 650 μm long, orientation at 17°-34°) initiate at the middle region of the contact interface. As the increase of the bolt pretension load (from 6000 N to 10 000 N), the crack initial location is getting away from the bolt screw, and the fretting fatigue lives is increasing (from 7.8 × 105 to 6.0 × 106). With the fatigue phenomenon and the stress field analysis result, it concludes that the crack initiation is governed by the maximum shear stress; the bolt pretension load and the additional rotate torque caused by the bearing load are the two main factors which affect the fretting fatigue mechanism of the bearing cap bolted joints. It is beneficial to fretting fatigue lives of the bearing cap joints by increasing the bolt pretension load and restraining the oscillation of the bearing cap.

  15. Factors Influencing the Quality of Encapsulation in Rock Bolting

    Science.gov (United States)

    Aziz, Naj; Craig, Peter; Mirzaghorbanali, Ali; Nemcik, Jan

    2016-08-01

    Bolt installation quality is influenced by various factors, some are well known and others are less recognised. A programme of field and laboratory studies was undertaken to examine various factors of relevance to the load transfer mechanism between the bolt, resin and rock to ensure test methods truly represent field performance. Short encapsulation tests were undertaken as part of the Australian Coal Association Research Program (ACARP) funded project (C21011) with the ultimate aim of developing standard test methods for assessing bolt encapsulation with chemical resin anchor installations. The field study consisted of a series of Short Encapsulation Pull Tests (SEPT) carried out in three mines with different geological conditions to determine the most representative and practical method of SEPT. Additional field work included installation of bolts into threaded steel tubes for subsequent removal and laboratory evaluation. A series of pull tests was carried out by installing bolts in overhead rig mounted sandstone block, cast in concrete with controlled encapsulation length. Factors of importance considered included; borehole diameter, resin annulus thickness, installation time (including bolt spin to the back and "spin at back"), the effect of gloving and hole over drill. It was found that the borehole diameter had a detrimental effect on the encapsulation bonding strength. Bolt installation time of approximately 10 s constituted an acceptable time for effective bolt installation and within the resin manufacturers recommended time of 14 s. Maintaining constant length of encapsulation was paramount for obtaining consistency and repeatability of the test results. Finally, a numerical simulation study was carried out to assess the capabilities of FLAC 2D software in simulating the pull testing of rock bolts.

  16. Epigenomics and bolting tolerance in sugar beet genotypes.

    Science.gov (United States)

    Hébrard, Claire; Peterson, Daniel G; Willems, Glenda; Delaunay, Alain; Jesson, Béline; Lefèbvre, Marc; Barnes, Steve; Maury, Stéphane

    2016-01-01

    In sugar beet (Beta vulgaris altissima), bolting tolerance is an essential agronomic trait reflecting the bolting response of genotypes after vernalization. Genes involved in induction of sugar beet bolting have now been identified, and evidence suggests that epigenetic factors are involved in their control. Indeed, the time course and amplitude of DNA methylation variations in the shoot apical meristem have been shown to be critical in inducing sugar beet bolting, and a few functional targets of DNA methylation during vernalization have been identified. However, molecular mechanisms controlling bolting tolerance levels among genotypes are still poorly understood. Here, gene expression and DNA methylation profiles were compared in shoot apical meristems of three bolting-resistant and three bolting-sensitive genotypes after vernalization. Using Cot fractionation followed by 454 sequencing of the isolated low-copy DNA, 6231 contigs were obtained that were used along with public sugar beet DNA sequences to design custom Agilent microarrays for expression (56k) and methylation (244k) analyses. A total of 169 differentially expressed genes and 111 differentially methylated regions were identified between resistant and sensitive vernalized genotypes. Fourteen sequences were both differentially expressed and differentially methylated, with a negative correlation between their methylation and expression levels. Genes involved in cold perception, phytohormone signalling, and flowering induction were over-represented and collectively represent an integrative gene network from environmental perception to bolting induction. Altogether, the data suggest that the genotype-dependent control of DNA methylation and expression of an integrative gene network participate in bolting tolerance in sugar beet, opening up perspectives for crop improvement. PMID:26463996

  17. Explosive Bolt Dual-Initiated from One Side

    Science.gov (United States)

    Snow, Eric

    2011-01-01

    An explosive bolt has been developed that has a one-sided dual initiation train all the way down to the pyro charge for high reliability, while still allowing the other side of the bolt to remain in place after actuation to act as a thermal seal in an extremely high-temperature environment. This lightweight separation device separates at a single fracture plane, and has as much redundancy/reliability as possible. The initiation train comes into the explosive bolt from one side.

  18. Study on full-length recoverable resin-metal bolts

    Institute of Scientific and Technical Information of China (English)

    孙玉宁; 康全玉

    2003-01-01

    The paper introduces a kind of full-length recoverable resin-metal bolts, expounds its structural principle and stress features, and gives some instances in laboratory tests and underground tests. The results show that full-length recoverable resin-metal bolts can be used for supporting the walls of class Ⅰ~Ⅲ mining gateways, that the anchoring force is 50 kN or so, and that the recoverability rate is more than 80%, thus the supporting effect is better than that of split-set bolts.

  19. An Experimental Method for Measuring the Clamping Force in Double Lap Simple Bolted and Hybrid (Bolted-Bonded) Joints

    OpenAIRE

    Goldarag, Firooz Esmaeili; Barzegar, Sajjad; Babaei, Alireza

    2015-01-01

    In this research, an experimental method for measuring the clamping force as a result of tightening torque in double lap simple bolted and hybrid (bolted-bonded) joints is proposed. Two types of joints, i.e. double lap simple and hybrid (bolted-bonded) joints were prepared for testing. In order to measure the clamping force or pretension resulting from the tightening torque at different applied torques, for both types of joints, a special experimental method was designed using a steel bush th...

  20. Test and application of hydraulic expansion bolts in a roadway under goaf with ultra-close separation

    Institute of Scientific and Technical Information of China (English)

    Wang Xiangyu; Bai Jianbiao; Guo Guanlong; Yu Yang

    2014-01-01

    The roof of a roadway under goaf with ultra-close separation consists of thin rock strata and rocks caving in upper goaf. Influenced by the mining of the upper coal seam, the roof is loose and broken, and its integ-rity is poor. Resin anchored bolts cannot provide an effective anchoring force in such roof conditions. By conducting free expansion tests and field pull-out tests on a hydraulic expansion bolt, this study has ana-lyzed the influencing factors and laws of radial expansion and anchoring force changes in the rod body. This has revealed the anchoring mechanism of such bolts, and has obtained reasonable water injection pressures and suitable drilling diameters (which are 20–25 MPa and 32–35 mm respectively) for the hydraulic expansion bolt (u28 mm) used in these tests. Based on pull-out tests at different interlayer spacing, the applicability of hydraulic expansion bolts had been verified for controlling the roof of road-ways under goaf with ultra-close distance. Combined with the deformation and failure characteristics of the test roadway roof, this paper proposes a united roof-control technology based on the use of hydraulic expansion bolts and advancing intubation for the roof. Engineering practice indicated that the roof of the test roadway did not generate leaking and caving phenomenon, and the amount of roof deformation was controlled to within 150 mm. Maintenance of the roadway roof has been improved significantly, which ensures safe mining in coal seams with ultra-close separation.

  1. Beam to Column Timber Joints with Pretensioned Bolts

    Directory of Open Access Journals (Sweden)

    Hayashikawa T.

    2011-01-01

    Full Text Available The effects of pretension in bolts on hysteretic response of timber joints exposed to a bending had been reported by the authors, but the cyclic tests were carried out at small displacement level which might not be applicable for earthquake-resistance design. In this study, similar cyclic tests but at large displacement levels were conducted. Beam to column timber joints with steel side plates were fabricated and continuously loaded until failure. At connection, the bolts were pretension in four different magnitudes: 0 kN, 5 kN, 10 kN and 15 kN. The results showed that frictional action between the steel side plates and wood member as a result of bolt pretensioning significantly increased the (frictional hysteretic damping and the equivalent viscous damping ratio. It is obvious from the test results that the pretension force in bolts has no influence on the maximum joint resistance but decreases the joint rotational deformation.

  2. What Makes Usain Bolt Unique as a Sprinter?

    Science.gov (United States)

    Shinabargar, A. J.; Hellrich, Matt; Baker, Blane

    2010-09-01

    For both casual and avid fans alike, Olympic and other sporting events can provide a wealth of data for simple physics analyses. One of the most impressive performances in recent Olympic history is that of Usain Bolt in the track-and-field sprinting events during the 2008 Summer Games. Over a seven-day span, Bolt set world records in the 100-m and 200-m individual sprints and in the 4 × 100-m sprint relay. In addition, Bolt left us all wondering what record time he might have run had he not eased into the finish line in the 100-m dash. Naturally, one question many fans and observers immediately ask is: What makes Usain Bolt unique as a sprinter?

  3. Eddy-Current Detection of Weak Bolt Heads

    Science.gov (United States)

    Messina, C. P.

    1987-01-01

    Electronic test identifies flawed units passing hardness tests. Eddy-current test detects weakness in head-to-shank junctions of 1/4-28 cup-washer lock bolts. Developed for alloy A286 steel bolts in Space Shuttle main engine fuel turbo-pump. Test examines full volume of head, including head-to-shank transition and nondestructively screens out potentially defective units. Test adapts to any other alloys.

  4. What Makes Usain Bolt Unique as a Sprinter?

    Science.gov (United States)

    Shinabargar, A. J.; Hellrich, Matt; Baker, Blane

    2010-01-01

    For both casual and avid fans alike, Olympic and other sporting events can provide a wealth of data for simple physics analyses. One of the most impressive performances in recent Olympic history is that of Usain Bolt in the track-and-field sprinting events during the 2008 Summer Games. Over a seven-day span, Bolt set world records in the 100-m and…

  5. A novel method for detecting second harmonic ultrasonic components generated from fastened bolts

    Science.gov (United States)

    Fukuda, Makoto; Imano, Kazuhiko

    2012-09-01

    This study examines the use of ultrasonic second harmonic components in the quality control of bolt-fastened structures. An improved method for detecting the second harmonic components, from a bolt fastened with a nut, using the transmission method is constructed. A hexagon head iron bolt (12-mm diameter and 25-mm long) was used in the experiments. The bolt was fastened using a digital torque wrench. The second harmonic component increased by approximately 20 dB before and after the bolt was fastened. The sources of second harmonic components were contact acoustic nonlinearity in the screw thread interfaces of the bolt-nut and were the plastic deformation in the bolt with fastening bolt. This result was improved by approximately 10 dB compared with previous our method. Consequently, usefulness of the novel method for detecting second harmonic ultrasonic components generated from fastened bolt was confirmed.

  6. Developing a highly reliable cae analysis model of the mechanisms that cause bolt loosening in automobiles

    Directory of Open Access Journals (Sweden)

    Ken Hashimoto

    2014-10-01

    Full Text Available In this study, we developed a highly reliable CAE analysis model of the mechanisms that cause loosening of bolt fasteners, which has been a bottleneck in automobile development and design, using a technical element model for highly accurate CAE that we had previously developed, and verified its validity. Specifically, drawing on knowledge gained from our clarification of the mechanisms that cause loosening of bolt fasteners using actual machine tests, we conducted an accelerated bench test consisting of a threedimensional vibration load test of the loosening of bolt fasteners used in mounts and rear suspension arms, where interviews with personnel at an automaker indicated loosening was most pronounced, and reproduced actual machine tests with CAE analysis based on a technical element model for highly accurate CAE analysis. Based on these results, we were able to reproduce dynamic behavior in which larger screw pitches (lead angles lead to greater non-uniformity of surface pressure, particularly around the nut seating surface, causing loosening to occur in areas with the lowest surface pressure. Furthermore, we implemented highly accurate CAE analysis with no error (gap compared to actual machine tests.

  7. Identification of bolting-related microRNAs and their targets reveals complex miRNA-mediated flowering-time regulatory networks in radish (Raphanus sativus L.).

    Science.gov (United States)

    Nie, Shanshan; Xu, Liang; Wang, Yan; Huang, Danqiong; Muleke, Everlyne M; Sun, Xiaochuan; Wang, Ronghua; Xie, Yang; Gong, Yiqin; Liu, Liwang

    2015-01-01

    MicroRNAs (miRNAs) play vital regulatory roles in plant growth and development. The phase transition from vegetative growth to flowering is crucial in the life cycle of plants. To date, miRNA-mediated flowering regulatory networks remain largely unexplored in radish. In this study, two small RNA libraries from radish leaves at vegetative and reproductive stages were constructed and sequenced by Solexa sequencing. A total of 94 known miRNAs representing 21 conserved and 13 non-conserved miRNA families, and 44 potential novel miRNAs, were identified from the two libraries. In addition, 42 known and 17 novel miRNAs were significantly differentially expressed and identified as bolting-related miRNAs. RT-qPCR analysis revealed that some miRNAs exhibited tissue- or developmental stage-specific expression patterns. Moreover, 154 target transcripts were identified for 50 bolting-related miRNAs, which were predominately involved in plant development, signal transduction and transcriptional regulation. Based on the characterization of bolting-related miRNAs and their target genes, a putative schematic model of miRNA-mediated bolting and flowering regulatory network was proposed. These results could provide insights into bolting and flowering regulatory networks in radish, and facilitate dissecting the molecular mechanisms underlying bolting and flowering time regulation in vegetable crops. PMID:26369897

  8. Guideline for bolted joint design and analysis : version 1.0.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Kevin H.; Morrow, Charles W.; Durbin, Samuel; Baca, Allen

    2008-01-01

    This document provides general guidance for the design and analysis of bolted joint connections. An overview of the current methods used to analyze bolted joint connections is given. Several methods for the design and analysis of bolted joint connections are presented. Guidance is provided for general bolted joint design, computation of preload uncertainty and preload loss, and the calculation of the bolted joint factor of safety. Axial loads, shear loads, thermal loads, and thread tear out are used in factor of safety calculations. Additionally, limited guidance is provided for fatigue considerations. An overview of an associated Mathcad{copyright} Worksheet containing all bolted joint design formulae presented is also provided.

  9. Effects of Anchor Bolts Failures in Steam Explosion Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Hyun; Chang, Yoon-Suk [Kyung Hee University, Yongin (Korea, Republic of); Song, Sungchu; Cho, Yong-Jin [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-05-15

    Steam explosion may occur in a nuclear power plant by molten core-coolant interactions when the external reactor vessel cooling strategy is failed. This phenomenon can threat the integrity of reactor cavity, penetration piping and support structures. Even though extensive researches have been performed to predict influences of the steam explosion, due to complexity of physical phenomena and environmental thermal hydraulic conditions, it is remained as one of possible hazards. A steam explosion can cause intensive and rapid heat transfer, and lead to the formation of pressure waves and production of missiles that may endanger surrounding reactor cavity wall and associate components due to resulting dynamic effects. The goal of this research is to examine structural integrity of RPV (Reactor Pressure Vessel) support structures and anchor bolts under typical ex-vessel steam explosion conditions through FE analyses. Particularly, influence due to the failure of anchor bolts connecting RPV and support structures was evaluated. In this paper, influence of RPV and support structure due to the anchor bolt failure were evaluated under typical steam explosion conditions and the following conclusions were derived. The highest maximum stresses were calculated at the support structures under the steam explosion condition with the SVF and anchor bolts non-failure. The all stress values did not exceed their yield strengths. The displacements were high under anchor bolt failure conditions. However, the vertical movements of major components were small comparing to the overall dimensions of them.

  10. A Requirements Analysis Model Based on QFD

    Institute of Scientific and Technical Information of China (English)

    TANG Zhi-wei; Nelson K.H.Tang

    2004-01-01

    The enterprise resource planning (ERP) system has emerged to offer an integrated IT solution and more and more enterprises are increasing by adopting this system and regarding it as an important innovation. However, there is already evidence of high failure risks in ERP project implementation, one major reason is poor analysis of the requirements for system implementation. In this paper, the importance of requirements analysis for ERP project implementation is highlighted, and a requirements analysis model by applying quality function deployment (QFD) is presented, which will support to conduct requirements analysis for ERP project.

  11. Application of ultrasonic phased array technique for inspection of stud bolts in nuclear reactor vessel

    International Nuclear Information System (INIS)

    The stud bolt is one of crucial parts for safety of reactor vessels in nuclear power plants. Cracks initiation and propagation were reported in stud bolts using closure of reactor vessel and head. Stud bolts are inspected by ultrasonic technique during overhaul periodically for the prevention of stud bolt failure and radioactive leakage from nuclear reactor. In conventional ultrasonic testing for inspection of stud bolts, crack was detected by using shadow effect. It take too much time to inspect stud bolt by using conventional ultrasonic technique. In addition, there were numerous spurious signal reflected from every thread. In this study, the advanced ultrasonic phased array technique was introduced for inspect stud bolts. The phased array technique provide fast inspection and high detectability of defects. There are sector scanning and linear scanning method in phased array technique, and these scanning methods were applied to inspect stud bolt and detectability was investigated.

  12. The strength of Glued-in Bolts after 9 Years In Situ Loading

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Damkilde, Lars;

    1996-01-01

    An experimental determination of the remaining strength of glued-in bolts after 9 years is presented. The hollow tapered bolts served as the blade to rotor hub connection of a windmill with wooden blades. The test method is presented along with the load history of the bolts, the recorded residual...... strength, the observed fracture modes and the force displacements curves. A total of 11 bolts were pulled out between undamaged bolts. The mean strength was found to be 362 kN with a standard deviation of 37 kN. This residual strength is 95% of previously recorded data. At fracture, a displacement between...... 0.4 mm and 1.0 mm was observed. In the majority of failures the bolts were pulled out like a cork from a bottle. A FEM-analysis confirms the higher load bearing capacity of the special hollowed tapered bolts compared to solid bolts....

  13. Mechanical mechanism and support design analysis on bolt-beam-net support in soft rock roadway in Qigou Coal Mine

    Institute of Scientific and Technical Information of China (English)

    LI Tao; SHAN Ren-liang; HAN Huan-shang; YANG Wei-hong; LIU Nian

    2012-01-01

    The deformation and failure mechanical mechanism in soft rock roadway is related to the stability of supported tunnels,which is important to coal mine production and construction.By physical mechanics experiments and X-ray diffraction (XRD) tests,the engineering mechanical properties of soft rock,as well as main mineral composition of the surrounding soft rock of Qigou Coal Mine,were obtained.Based on analysis results,a method using bolt-beam-net combination to support was put forward.Mechanical analysis of the support form was done by using the calculation software FLAC3D.Results show that clay minerals of this mine are kaolinite and illite mixed layer,of which the water absorption is relatively obvious and presented mudding characteristic after absorbing water,with the plasticity index of 0.35,with small expansibility,which is weakly consolidated colloid with strong connected force in unit cell.The rock blocks have the characteristics of moisture absorption softening,and the deformation mechanical mechanism of which is with the coexistence of molecular expansive mechanism,colloid expansive mechanism,and weak layer trend type.The calculation results show that the bolt-beam-net support structure makes the bolt,beam,and roof deform compatibly.The beams make the force in the bolt relatively homogeneous,which restricts the displacement of the tunnel roof as well.Finally,using in situ monitoring,the numerical results were verified.

  14. TENSILE STRESS RELAXATION OF TURBINE BOLT STEELS AT HIGH TEMPERATURE

    Institute of Scientific and Technical Information of China (English)

    G.Q. Jia; H.W. Shen; Y.M. Zhu

    2004-01-01

    Stress relaxation behavior of two turbine bolt steels was evaluated by the manualcontrolled tensile stress relaxation test (TSRT) at high temperature. First, feasibility and the procedure of the manual-controlled tensile stress relaxation test (TSRT) is discussed and carried out on a general creep testing machine. And then, the experimental results from such type of test were compared to the existing data provided by certain Laboratory U.K. Overall good agreement between the results of manualcontrolled TSRT method and the existing data provides confidence in the use of the proposed method in practice. Finally, the experimental results of turbine bolt steels from TSRT were compared with that of bending test. It is observed that great difference exists between the results from two different type stress relaxation tests. It is therefore suggested that the results from TSRT method be adopted in turbine bolt design in engineering.

  15. Development of plastic media blasting device for stud bolt

    International Nuclear Information System (INIS)

    Plastic media blasting is a mechanical cleaning method for removing paint, rust and/or anti-galling material etc on the surface of metal without damaging the metal surface. The method is suitable for cleaning the surface of reusable elements and parts such as bolts and nuts. Anti-galling material such as molybdenum disulfide is applied to fastening stud bolts used for the steam turbine rotor casing. It is necessary to remove this material when new anti-galling material is to be applied. Genden Engineering Services and Construction Co., and Morikawa Industries Corp., have developed a plastic media blasting device to clean the surface of stud bolt screw threads installed in the facility such as lower casing of the turbine. This paper reports the outline of the results. (author)

  16. Analysis Of Comparative Strength Model Connection Bolts And Weld To The Plate Materials ST. 42

    OpenAIRE

    Saripuddin. M; Hammada Abbas

    2015-01-01

    The research objective to be achieved is determine the ratio of tensile strength connections of weld combination (longitudinal and transversal) with a tensile strength of connection models with 2 bolts, 3 bolts and 4 bolts. The method used is to form specimens of weld connections (longitudinal and transverse) and the model of connections (2, 3 and 4) bolts, and testing of tensile strength using a tensile test machine to produce maximum load value, the maximum tension and strain. T...

  17. 基于ANSYS Workbench有螺栓预紧力的冲压法兰的有限元模态分析%FEM modal analysis for pressed flanges preload by bolt based on ANSYS workbench

    Institute of Scientific and Technical Information of China (English)

    闵加丰; 朱海清

    2012-01-01

    冲压松套钢制管法兰(简称冲压法兰)是一种新型的非标管法兰,具有结构独特、加工工艺简单、材料消耗小等显著特点.由于缺乏相应国家标准,限制了冲压法兰的推广使用.针对冲压法兰在振动设备上使用时容易产生共振或疲劳的问题进行研究,运用Pro/E建立冲压法兰的有限元模型,通过Pro/E与ANSYSWorkbench之间的无缝连接导入,借助ANSYS Workbench有限元软件对受螺栓预紧力的冲压法兰进行受力分析,在此基础上对其进行模态分析,得到10阶固有频率、振型和应变云图.%Pressed flanges (which is short for pressed loose steel pipe flanges) is a new type of non-standard. The unique structure of the flanges can greatly gave materials with simple processing technology. As the lack of corresponding national standards, the wide application of pressed flanges has been limited. The resonance and fatigue problems of pressed flange on the vibrating machine have been studied. The solid modal of pressed flanges has been built with Pro/E software, which leads in to ANSYS Workbench by seamless connection. The stress analysis of pressed flanges preload by bolt has been completed with help of ANSYS Workbench. Then modal analysis has been executed to obtain 10 ranks frequency, vibration models and stress chart.

  18. Cable bolt bearing capacity - an in situ parametric study

    Czech Academy of Sciences Publication Activity Database

    Souček, Kamil; Waclawik, Petr; Koníček, Petr; Ptáček, Jiří; Hastíková, Alice; Kukutsch, Radovan

    Montreal, Quebec: ISRM, 2015. ISBN 978-1-926872-25-4. [International Symposium on Rock Mechanics /13./. Montreal, Quebec (CA), 10.05.2015-13.05.2015] R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406; GA MV VG20102014034 Institutional support: RVO:68145535 Keywords : cable bolt * Cable-Resin-Rock system (CRR system) * bolt borehole ratio * system stiffness * bearing capacity Subject RIV: JQ - Machines ; Tools http://www.isrm2015.com/

  19. STRESS-STRAIN FINITE ELEMENT ANALYSIS AND FATIGUE LIFE PREDICTION FOR BOLTED CONNECTIONS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A cyclic plasticity model is used into finite element (FE) method to obtain the details of elastic-plastic stress-strain in the bolts under cyclic axial loading. Two criteria in multiaxial fatigue are employed to predict fatigue lives of bolts. The predicted fatigue lives are in favorable agreement with the experimental results for machined bolts.

  20. Characterization of an Unusual Cytoplasmic Chimera Detected in Bolting Garlic (Allium sativum L.) Clones

    Science.gov (United States)

    Production of a visible flower stalk or bolting has been used as a major trait to categorize garlic clones. Analysis of mitochondrial genome variation with PCR revealed differences between bolting and non-bolting clones of garlic. Screening 333 garlic accessions from diverse geographic origins rev...

  1. Ricci flows connecting Taub-Bolt and Taub-NUT metrics

    International Nuclear Information System (INIS)

    We use the Ricci flow with surgery to study four-dimensional SU(2) x U(1)-symmetric metrics on a manifold with fixed boundary given by a squashed 3-sphere. Depending on the initial metric we show that the flow converges to either the Taub-Bolt or the Taub-NUT metric, the latter case potentially requiring surgery at some point in the evolution. The Ricci flow allows us to explore the Euclidean action landscape within this symmetry class. This work extends the recent work of Headrick and Wiseman (2006 Class. Quantum Grav. 23 6683) to more interesting topologies

  2. Apparatus For Eddy-Current Inspection Of Bolts

    Science.gov (United States)

    Amos, Jay M.

    1994-01-01

    Eddy-current apparatus for inspection of bolts, studs, and other threaded fasteners detects flaws in threads, shanks, and head fillets. With help of apparatus, technician quickly inspects fasteners of various dimensions. Accommodates fasteners with diameters from 0.190 in. to 1 in. and with lengths up to 5 in. Basic design modified to accommodate fasteners of other sizes.

  3. Modal Experiments and Finite Element Analysis of the Bolted Structure Considering Interface Stiffness and Prtension

    Institute of Scientific and Technical Information of China (English)

    WEI Li-dui; DUAN Shu-lin; WU Ji; WU Qi-li; XING Hui

    2012-01-01

    It is particularly important to evaluate natural frequencies and natural modes of the structure of bolted joints to avoid the failures of the structure due to the resonance. The vibration characteristics of bolted structures are closely connected to surface roughness of contact interfaces, the magnitude of pretension of the bolts and the number of clamping bolts. In this paper, the effect of the factors above on the natural frequencies of bolted structures is sys- tematically investigated by experiments. Then, the finite element method is applied to analyze the effect. Finally, the numerical method is validated by experimental measurements of the natural frequencies.

  4. Controllable theory and applications for the wall bolting reinforcement in the roadway of seam

    Institute of Scientific and Technical Information of China (English)

    TAN Yun-liang; ZHANG Li-jun; XIAO Ya-xun

    2007-01-01

    By using the Radar penetrating technology and numerical simulations, the fractured zone could be easily determined. Both wall fractured zone and mining action of coal seam roadway were considered, and the bolt reinforcing criteria for wall including low limit condition and up limit condition were put up, which supply a basis for the bolt reinforcement design. For a particular engineering, there existed a bolt reinforcing controllable range which can be determined by the method put up in this paper. For the out of controllable range of bolt reinforcement in engineering, it is necessary to seek for other kind reinforcing technology, because the bolt reinforcing technology is not omnipotent.

  5. Numerical analysis of bolted connections in cold-formed steel members

    Directory of Open Access Journals (Sweden)

    Jorge Munaiar Neto

    2006-02-01

    Full Text Available This paper presents three-dimensional numerical models of bolted connections of cold-formed steel members. The purpose of three-dimensional numerical models is to evaluate the strength and the behavior of these connections. The computer code ANSYS v. 6.0, based on Finite Element Method, was used to analyze the numerical models response. In order to evaluate the efficiency and reliability of the constructed models, the numerical results were compared with experimental results obtained from experimental assays carried out in Structures Laboratory of EESC/USP. In this sense, the numerical results presented satisfactory agreement when compared with experimental results.

  6. Chocolate Bars Based on Human Nutritional Requirements

    OpenAIRE

    Robson, Anthony

    2013-01-01

    International audience Key Points * The nutritional value of chocolate bars should be based on the nutritional value of the low energy dense late Paleolithic human diet to help reduce mental ill health, obesity, and other postprandial insults. * Current chocolate bars have a high energy density (>2 kcal/g). * Cocoa can be sweetened by the addition of calorie-free Purefruit™ (Tate & Lyle) monk fruit ( Siraitia grosvenorii ) extract. PUREFRUIT™ is approximately 200 times sweeter than sugar a...

  7. The Use of the Direct Optimized Probabilistic Calculation Method in Design of Bolt Reinforcement for Underground and Mining Workings

    Directory of Open Access Journals (Sweden)

    Martin Krejsa

    2013-01-01

    Full Text Available The load-carrying system of each construction should fulfill several conditions which represent reliable criteria in the assessment procedure. It is the theory of structural reliability which determines probability of keeping required properties of constructions. Using this theory, it is possible to apply probabilistic computations based on the probability theory and mathematic statistics. Development of those methods has become more and more popular; it is used, in particular, in designs of load-carrying structures with the required level or reliability when at least some input variables in the design are random. The objective of this paper is to indicate the current scope which might be covered by the new method—Direct Optimized Probabilistic Calculation (DOProC in assessments of reliability of load-carrying structures. DOProC uses a purely numerical approach without any simulation techniques. This provides more accurate solutions to probabilistic tasks, and, in some cases, such approach results in considerably faster completion of computations. DOProC can be used to solve efficiently a number of probabilistic computations. A very good sphere of application for DOProC is the assessment of the bolt reinforcement in the underground and mining workings. For the purposes above, a special software application—“Anchor”—has been developed.

  8. A clamping force measurement system for monitoring the condition of bolted joints on railway track joints and points

    International Nuclear Information System (INIS)

    Many industrial structures associated with railway infrastructures rely on a large number of bolted joint connections to ensure safe and reliable operation of the track and trackside furniture. Significant sums of money are spent annually to repair the damage caused by bolt failures and to maintain the integrity of bolted structures. In the UK, Network Rail (the organization responsible for rail network maintenance and safety) conducts corrective and preventive maintenance manually on 26,000 sets of points (each having approximately 30 bolted joints per set), in order to ensure operational success and safety for the travelling public. Such manual maintenance is costly, disruptive, unreliable and prone to human error. The aim of this work is to provide a means of automatically measuring the clamping force of each individual bolted joint, by means of an instrumented washer. This paper describes the development of a sensor means to be used in the washer, which satisfies the following criteria. 1. Sense changes in the clamping force of the joint and report this fact. 2. Provide compatibility with the large dynamic range of clamping force. 3. Satisfy the limitations in terms of physical size. 4. Provide the means to electronically interface with the washer. 5. Provide a means of powering the washer in situ. 6. Provide a solution at an acceptable cost. Specifically the paper focuses on requirements 1, 2 and 3 and presents the results that support further development of the proposed design and the realization of a pre-prototype system. In the paper, various options for the force sensing element (strain gage, capacitor, piezo-resistive) have been compared, using design optimization techniques. As a result of the evaluation, piezo-resistive sensors in concert with a proprietary force attenuation method, have been found to offer the best performance and cost trade-off The performance of the novel clamping force sensor has been evaluated experimentally and the results show

  9. A clamping force measurement system for monitoring the condition of bolted joints on railway track joints and points

    Science.gov (United States)

    Tesfa, B.; Horler, G.; Thobiani, F. Al; Gu, F.; Ball, A. D.

    2012-05-01

    Many industrial structures associated with railway infrastructures rely on a large number of bolted joint connections to ensure safe and reliable operation of the track and trackside furniture. Significant sums of money are spent annually to repair the damage caused by bolt failures and to maintain the integrity of bolted structures. In the UK, Network Rail (the organization responsible for rail network maintenance and safety) conducts corrective and preventive maintenance manually on 26,000 sets of points (each having approximately 30 bolted joints per set), in order to ensure operational success and safety for the travelling public. Such manual maintenance is costly, disruptive, unreliable and prone to human error. The aim of this work is to provide a means of automatically measuring the clamping force of each individual bolted joint, by means of an instrumented washer. This paper describes the development of a sensor means to be used in the washer, which satisfies the following criteria. Sense changes in the clamping force of the joint and report this fact. Provide compatibility with the large dynamic range of clamping force. Satisfy the limitations in terms of physical size. Provide the means to electronically interface with the washer. Provide a means of powering the washer in situ. Provide a solution at an acceptable cost. Specifically the paper focuses on requirements 1, 2 and 3 and presents the results that support further development of the proposed design and the realization of a pre-prototype system. In the paper, various options for the force sensing element (strain gage, capacitor, piezo-resistive) have been compared, using design optimization techniques. As a result of the evaluation, piezo-resistive sensors in concert with a proprietary force attenuation method, have been found to offer the best performance and cost trade-off The performance of the novel clamping force sensor has been evaluated experimentally and the results show that a smart washer

  10. Study on the Axial force and Assembly Torque value of Bolted Joint

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Il; Kim, Nak Jeom; Choi, Sang Hoon; Kim, Kyung Sub [Korea Plant Service and Enginccring Co., Seongnam (Korea, Republic of)

    2009-10-15

    When jointing high tension bolt, in order the nut rotary timely operates force we as the torque (Torque moment). The size of the torque is proportionate in axial force of bolt and diameter of bolt. This time the relationship with proportional torque coefficient in afterwards is expressed. T = k {center_dot} d {center_dot} N/1000 (1) Where, T : Jointed torque (Nm) (Nut rotate moment) k : Torque coefficient (Friction coefficient) d : Bolt diameter (mm) N : Bolt axial force (kN) When jointing a bolt with torque formula, design target axial force value according to it calculates a torque value. This time there is not a possibility of knowing the friction coefficient (Torque coefficient k) which is accurate. This coefficient to decide experimentally and influence bolt diameter, bolt material, tightening speed etc. According to type of lubricant which but, is used mostly it changes. It differs the lubricant of Wolsung 4 unit steam generator manway stud bolt jointing at the time of bolt from the present paper axial force it is a result which researches the result which it examines.

  11. Finite Element Modeling and Modal Analysis of Complicated Structure with Bolted Joints

    Institute of Scientific and Technical Information of China (English)

    PU Da-yu; LIAO Ri-dong; ZUO Zheng-xing; FENG Hui-hua

    2009-01-01

    A contact bolt model is proposed as a new modeling technique to investigate the complex structure with bolted joints for modal analysis and compared with the coupled bolt model, and the test results are given. Among these models, the coupled bolt model provides the best accurate responses compared with the experimental results. The contact bolt model shows the best effectiveness and usefulness in view of operational time. The bolt models proposed in this study are adopted for a dynamic characteristic analysis of a large diesel engine consisting of several parts which are connected by many bolts. The dynamic behavior of the entire engine structure was investigated by experiment. The coupled bolt model and the contact bolt model were applied to model the assembly of engine with high preload. The experimental results are in good agreement with the finite element method (FEM) results. Compared with the other models, the contact bolt model presented in this paper is more effective and useful in view of operational time and experience of analysts.

  12. Rotor characteristics experiments with cooling pipe/fender bolt-groups, HTR-500

    International Nuclear Information System (INIS)

    For the design of composite liners for prestressed concrete pressure vessels of high temperature reactors, the force-displacement relationship of rotor elements is required. The rotor elements link the liner with the vessel concrete and transfer loads between liner and concrete. The liner is mainly stressed only at the sheet level due to concrete upsetting because of external load, including creeping due to prestress, internal pressure and temperature, shrinkage and temperature difference between liner and concrete. In the region of planned peripheral disturbances (penetrations, sheet/transfers, etc.), and at places with unintentional imperfections (dents, points of impact with slightly different sheet thicknesses), the liner sheet may be displaced against the concrete. Such displacements lead to a shear load on fender bolts and cooling pipes. The strains develop slowly. They can also be cyclical owing to internal pressure and temperature changes, the amplitudes being low, however. In addition, tensile stress may be applied to the fender bolt rotors by the driving effect of the shear-stressed cooling pipes, by the liner bending strain at the edges of dented fields, or by external loads. (orig.)

  13. Desarrollo de Acotación Funcional de Bridas con Barrenos de Sujeción Development of Stack-up Tolerances for Bolted Flange Pairs

    Directory of Open Access Journals (Sweden)

    Eduardo Aguilera

    2006-01-01

    Full Text Available En este trabajo se presenta un método para establecer las tolerancias adecuadas para la fabricación y ensamble de dos bridas unidas por tornillos. Se llevó a cabo una solución cuidadosa de tolerancias dimensionales lineales y angulares para la ubicación de los agujeros considerando errores en su manufactura, así como variaciones en el diámetro de los tornillos usados en el ensamble. El trabajo se basa en análisis de tolerancias multidimensionales, cálculos de acotación funcional e intercambiabilidad total. También se toma en cuenta la forma específica del conjunto, para el cual se aplica un método estadístico que se verifica con el método de Monte Carlo. El procedimiento presentado en este artículo representa una posibilidad relativamente fácil de obtener buenos ensambles para conjuntos de bridas en casos reales de diseño y del taller de fabricación.This study presents a method for establishing adequate tolerances for the manufacture and assembly of flange pairs joined by bolts. A precise solution was made, considering the linear and angular dimensional tolerances required for the location of the flange assembly holes, considering errors in fabrication as well as variations in the diameters of the bolts used for assembly. The study is based on the analysis of multidimensional tolerances, calculations of stack-up tolerance and total interchangeability. Also taken into account was the specific form of the assembly, for which a statistical method was applied which was verified by the Monte Carlo method. The procedure presented in this article represents a relatively simple method for obtaining good flange assemblies based on actual design cases and their fabrication shops.

  14. Ballistics Analysis of Orion Crew Module Separation Bolt Cover

    Science.gov (United States)

    Howard, Samuel A.; Konno, Kevin E.; Carney, Kelly S.; Pereira, J. Michael

    2013-01-01

    NASA is currently developing a new crew module to replace capabilities of the retired Space Shuttles and to provide a crewed vehicle for exploring beyond low earth orbit. The crew module is a capsule-type design, which is designed to separate from the launch vehicle during launch ascent once the launch vehicle fuel is expended. The separation is achieved using pyrotechnic separation bolts, wherein a section of the bolt is propelled clear of the joint at high velocity by an explosive charge. The resulting projectile must be contained within the fairing structure by a containment plate. This paper describes an analytical effort completed to augment testing of various containment plate materials and thicknesses. The results help guide the design and have potential benefit for future similar applications.

  15. PLASMA NITRIDING FOR IMPROVING WEAR RESISTANCE OF CABLE BOLT

    OpenAIRE

    SHAOQING NIU; SHUANGSUO YANG; YI LI

    2013-01-01

    In order to improve the wear resistance of the cable bolt and increase its life-time during operation, plasma nitriding was employed to obtain a protective nitriding layer on its surface. The microstructure, phase constitution, microhardness and wear resistance of the nitriding layer were investigated. It was shown that continuous and dense nitriding layers were formed on the surface of the samples. The microhardness of the nitrided sample was enhanced by the formation of nitriding layer, whi...

  16. A Requirements Recommendation Method Based on Service Description

    Science.gov (United States)

    Ning, Da; Peng, Rong

    The development of Service oriented architecture (SOA) has brought new opportunities to requirements engineering. How to utilize existing services to guide the requestors to express their requirements accurately and completely becomes a new hotspot. In this paper, a requirements recommendation method based on service description was proposed. It can find web services corresponding to user's initial requirements, establish the association relationship between user's requirements and service functions, and in turn, recommend the associated service's functions to the requestor and assist him to express requirements accurately and completely. The effectiveness of this method is evaluated and demonstrated by a case-study in travel planning system.

  17. Structured Language Requirement Elicitation Using Case Base Reasoning

    OpenAIRE

    Marryam Murtaza; Jamal Hussain Shah; Aisha Azeem; Wasif Nisar; Maria Masood

    2013-01-01

    Requirement elicitation is very difficult process in highly challenging and business based software as well as in real time software. Common problems associated with these types of software are rapidly changing the requirements and understanding the language of the layman person. In this study, a framework for requirement elicitation by using knowledge based system is proposed, which is very helpful for knowledge documentation, intelligent decision support, self-learning and more specifically...

  18. Experimental study of friction in aluminium bolted joints

    Science.gov (United States)

    Croccolo, D.; de Agostinis, M.; Vincenzi, N.

    2010-06-01

    This study aims at developing an experimental tool useful to define accurately the friction coefficients in bolted joints and, therefore, at relating precisely the tightening torque to the bolt preloading force in some special components used in front motorbike suspensions. The components under investigation are some clamped joints made of aluminium alloy. The preloading force is achieved by applying a torque wrench to the bolt head. Some specific specimens have been appropriately designed and realized in order to study the tribological aspects of the tightening phase. Experimental tests have been performed by applying the Design of Experiment (DOE) method in order to obtain a mathematical model for the friction coefficients. Three replicas of a full factorial DOE at two levels for each variable have been carried out. The levels include cast versus forged aluminium alloy, anodized versus spray-painted surface, lubricated versus unlubricated screw, and first tightening (fresh unspoiled surfaces) versus sixth tightening (spoiled surfaces). The study considers M8x1.25 8.8 galvanized screws.

  19. AN EXPERIMENTAL STUDY ON THE RELAXATION OF BOLTS

    Directory of Open Access Journals (Sweden)

    Muhammad Abid

    2015-05-01

    Full Text Available Loss of pre-load with time, commonly known as ‘Relaxation’ is an established phenomena. Behaviour of a bolted joint depends upon the pre-load in the bolts in use, not the pre-load introduced by the mechanic. Loss of pre-load is expected due to the many factors such as embedment relaxation, gasket creep, elastic interactions, and vibration loosening or stress relaxation. In a gasketed joint, due to the gasket flexibility, relaxation is always substantial during preliminary passes, as 80 to 100% loss is not uncommon in almost all the bolts, resulting in a dynamic behaviour. Pre-load in a gasketed joint is stabilized and retained to certain extent in the final passes only. In a non-gasketed joint, due to no gasket and no rotation its static behaviour is concluded. This paper highlights the factors affecting the amount of relaxation with time and presents important considerations that can reduce this. Both the short and long term relaxations are recorded and a ‘best fit’ model for relaxation behaviour is derived.

  20. Experimental study of friction in aluminium bolted joints

    Directory of Open Access Journals (Sweden)

    Vincenzi N.

    2010-06-01

    Full Text Available This study aims at developing an experimental tool useful to define accurately the friction coefficients in bolted joints and, therefore, at relating precisely the tightening torque to the bolt preloading force in some special components used in front motorbike suspensions. The components under investigation are some clamped joints made of aluminium alloy. The preloading force is achieved by applying a torque wrench to the bolt head. Some specific specimens have been appropriately designed and realized in order to study the tribological aspects of the tightening phase. Experimental tests have been performed by applying the Design of Experiment (DOE method in order to obtain a mathematical model for the friction coefficients. Three replicas of a full factorial DOE at two levels for each variable have been carried out. The levels include cast versus forged aluminium alloy, anodized versus spray-painted surface, lubricated versus unlubricated screw, and first tightening (fresh unspoiled surfaces versus sixth tightening (spoiled surfaces. The study considers M8x1.25 8.8 galvanized screws.

  1. Expression of NO scavenging hemoglobin is involved in the timing of bolting in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Hebelstrup, Kim Henrik; Jensen, Erik Østergaard

    2008-01-01

    -symbiotic hemoglobin gene, GLB2, in Arabidopsis thaliana. Lines with GLB1 silencing had a significant delay of bolting and after bolting, shoots reverted to the rosette vegetative phase by formation of aerial rosettes at lateral meristems. Lines with overexpression of GLB1 or GLB2 bolted earlier than wild type plants....... By germinating the lines in a medium containing the nitric oxide (NO) donor, sodium nitroprusside (SNP), it was demonstrated that both GLB1 and GLB2 promote bolting by antagonizing the effect of NO, suggesting that non-symbiotic plant hemoglobin controls bolting by scavenging the floral transition...... with an optimum at low concentrations. It was observed that overexpression of either GLB1 or GLB2 shifts the optimum for NO growth stimulation to a higher concentration. In conclusion, we have found that expression of NO scavenging plant hemoglobin is involved in the control of bolting in Arabidopsis....

  2. Introducing aggregate into grouting material and its influence on load transfer of the rock bolting system

    Institute of Scientific and Technical Information of China (English)

    Cao Chen; Ren Ting; Chris Cook

    2014-01-01

    A fully grouted bolt provides greater shear load capacity for transmitting the load from the rock to the bolt, and vice versa. When grout fills irregularities between the bolt and the rock, a keying effect is cre-ated to transfer the load to the bolt via shear resistance at the interface and within the grout. Previous research has revealed that the mechanical properties of the grout had a great impact on the load transfer capacity of the rock bolting system. This paper presents a method to enhance the rock bolting strength by introducing metal granules into the grouting material. Experimental results suggest that both the average peak load of pullout tests and the total energy absorption of the system will increase if some metal gran-ules are mixed into the resin.

  3. Structured Language Requirement Elicitation Using Case Base Reasoning

    Directory of Open Access Journals (Sweden)

    Marryam Murtaza

    2013-12-01

    Full Text Available Requirement elicitation is very difficult process in highly challenging and business based software as well as in real time software. Common problems associated with these types of software are rapidly changing the requirements and understanding the language of the layman person. In this study, a framework for requirement elicitation by using knowledge based system is proposed, which is very helpful for knowledge documentation, intelligent decision support, self-learning and more specifically it is very helpful for case based reasoning and explanation. Basically in this method requirements are gathered from Artificial Intelligence (AI expert system from various sources e.g., via interviews, scenarios or use cases. Then, these are converted into structured natural language using ontology and this new problem/case is put forward to Case Based Reasoning (CBR. CBR based on its previous information having similar requirements combines with new case and suggests a proposed solution. Based on this solution a prototype is developed and delivered to customer. The use of case-based reasoning in requirements elicitation process has greatly reduced the burden and saved time of requirement analyst and results in an effective solution for handling complex or vague requirements during the elicitation process.

  4. Shape memory alloy-based moment connections with superior self-centering properties

    Science.gov (United States)

    Farmani, Mohammad Amin; Ghassemieh, Mehdi

    2016-07-01

    Superelastic shape memory alloys (SMAs) have the potential to create a spontaneous recentering mechanism on the connections of a structural system under seismic actions, which results in mitigation of the damage in the main structural members. In this article, innovative types of steel beam-to-column moment connections incorporating SMA bolts and plates are introduced and studied through a numerical approach. First, SMA bolted end-plate connection model is produced and analyzed by means of the finite element method to validate the numerical analysis against the prior experimental results. Then, the performance of eleven different end-plate moment connection models subjected to cyclic loading is investigated. By selecting the lower values for the moment capacity based on bolts strength in comparison to the flexural resistance of the beam, the plastic hinge is transferred from the beam section to the beam–column interface. Hence, employing superelastic materials at the connection interface could be potentially effective in providing the desired self-centering effect in the connection. To this end, the impact of utilizing superelastic SMA bolts and end-plates instead of using the conventional structural steel on the overall cyclic response of the connections is evaluated in this study. Results show that extended end-plate connections equipped with SMA bolts and end-plates, if properly proportioned and detailed, not only exhibit a clear reduction in the residual drifts after a seismic event, but also can meet the ductility requirements with good energy dissipation and sufficient stiffness.

  5. Data Warehouse Requirements Analysis Framework: Business-Object Based Approach

    Directory of Open Access Journals (Sweden)

    Anirban Sarkar

    2012-01-01

    Full Text Available Detailed requirements analysis plays a key role towards the design of successful Data Warehouse (DW system. The requirements analysis specifications are used as the prime input for the construction of conceptual level multidimensional data model. This paper has proposed a Business Object based requirements analysis framework for DW system which is supported with abstraction mechanism and reuse capability. It also facilitate the stepwise mapping of requirements descriptions into high level design components of graph semantic based conceptual level object oriented multidimensional data model. The proposed framework starts with the identification of the analytical requirements using business process driven approach and finally refine the requirements in further detail to map into the conceptual level DW design model using either Demand-driven of Mixed-driven approach for DW requirements analysi

  6. Influence of Thread Root Radius on Maximum Local Stresses at Large Diameter Bolts under Axial Loading

    Directory of Open Access Journals (Sweden)

    Cojocaru Vasile

    2014-06-01

    Full Text Available In the thread root area of the threaded bolts submitted to axial loading occur local stresses, higher that nominal stresses calculated for the bolts. These local stresses can generate failure and can reduce the fatigue life of the parts. The paper is focused on the study of the influence of the thread root radius on the maximum local stresses. A large diameter trapezoidal bolt was subjected to a static analysis (axial loading using finite element simulation.

  7. The face bending behaviour of blind-bolted connections to concrete-filled hollow sections

    OpenAIRE

    Elamin, Ahmed Mohamed Elamin Ahmed

    2014-01-01

    Structural Hollow Sections have superior structural performance over open sections and are currently available as circular, elliptical or rectangular sections. However, the practical use of these sections is limited due to complexities involved in their connections. The lack of access to the interior of the section makes it almost impossible to use standard bolted connections. The so-called Blind Bolts are therefore used as fasteners to alleviate these complexities by allowing for bolted rath...

  8. Verifying real-time systems against scenario-based requirements

    DEFF Research Database (Denmark)

    Larsen, Kim Guldstrand; Li, Shuhao; Nielsen, Brian;

    2009-01-01

    We propose an approach to automatic verification of real-time systems against scenario-based requirements. A real-time system is modeled as a network of Timed Automata (TA), and a scenario-based requirement is specified as a Live Sequence Chart (LSC). We define a trace-based semantics for a kerne...... problem. We show how this is accomplished in the context of the Uppaal model checker....

  9. A real-time visual inspection method of fastening bolts in freight car operation

    Science.gov (United States)

    Nan, Guo; Yao, JunEn

    2015-10-01

    A real-time inspection of the key components is necessary for ensuring safe operation of freight car. While traditional inspection depends on the trained human inspectors, which is time-consuming and lower efficient. With the development of machine vision, vision-based inspection methods get more railway on-spot applications. The cross rod end fastening bolts are important components on both sides of the train body that fixing locking plates together with the freight car main structure. In our experiment, we get the images containing fastening bolt components, and accurately locate the locking plate position using a linear Support Vector Machine (SVM) locating model trained with Histograms of Oriented Gradients (HOG) features. Then we extract the straight line segment using the Line Segment Detector (LSD) and encoding them in a range, which constitute a straight line segment dataset. Lastly we determine the locking plate's working state by the linear pattern. The experiment result shows that the localization accurate rate is over 99%, the fault detection rate is over 95%, and the module implementation time is 2f/s. The overall performance can completely meet the practical railway safety assurance application.

  10. Bolt Pull-Out Tests of Anchorage Body under Different Loading Rates

    Directory of Open Access Journals (Sweden)

    Tong-bin Zhao

    2015-01-01

    Full Text Available Based on the force analysis and mechanical transmission mechanism of grouting bolts, the self-developed test apparatus for interfacial mechanics is used to study the distribution rule of axial force and interfacial stress of bolts in anchorage body. At the same time, pull-out tests of anchorage body are simulated with the particle flow code software PFC2D, and stress distribution and failure patters are researched under different loading rates. The results show that the distribution of axial force and interfacial shear stress is nonuniform along the anchorage section: axial force decreases, shear force increases first and then decreases, and the maximum value of both of them is closed to the pull-out side; with the increase of loading rates, both of axial force and interfacial shear stress show a trend of increase in the upper anchorage section but changes are not obvious in the lower anchorage section, which causes serious stress concentration; failure strength of pull-out and loading rates show a linear correlation; according to loading rates’ impact on the anchoring effect, the loading rates’ scope can be divided into soft scope (v100 mm/s.

  11. Estimation of the Axial Stress in High-Tension Bolt by Acoustoelastic Method

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Hae Hwa; Lee, Tae Hoon; Jhang, Kyung Young [Hanyang University, Seoul (Korea, Republic of); Kim, Noh Yu [Korea University of Technology and Education, Cheonan (Korea, Republic of)

    2006-10-15

    The evaluation of clamping condition has been regarded as the main issue in the safety-maintenance of the clamped high-tension bolts. For this, this paper proposes a method to estimate the axial stress by measuring the Tofu (Time-Of-Flight) of ultrasonic wave, which is based on the acetylsalicylate or the dependency of sound speed on the stress. In this method, however, the variation of sound speed within the range of stress induced under the field condition is very small, and thus the accuracy of the Tofu measurement is important. We adopted the phase detection method using tone-burst ultrasonic wave to measure the precise Tofu. In order to verify the usefulness of the proposed method experiments are carried out and the results were compared with the stress measured by the strain gage. The results show good agreement with each other, and from these we can conclude that the proposed method is highly useful fnr the evaluation of clamping condition in the clamped high-tension bolts

  12. Effects of Rock Bolting on Stress Distribution around Tunnel Using the Elastoplastic Model

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To ensure the stability of a tunnel during construction, rock bolts are usually installed, which affects the stress distribution around the tunnel.Therefore, it is necessary to study the effects of rock bolting on the stress distribution around the tunnel.In this article, the effects of rock bolting on the stress distribution around the tunnel, including the position and orientation of bolts, the overburden depths, and the bolt lengths, are simulated using the ANSYS software with an elastoplastic model.The effect of multiple bolts of 2 m and 1 m lengths on the stress distribution in the roof and on the lateral sides of a tunnel and at different overburden depths is considered.An important finding is that the tensile stress region that is very dangerous for rock in the bottom of the tunnel grows rapidly with increasing overburden depths when rock bolts are installed only in the roof or on the lateral sides of a tunnel.The determination of the length of the rock bolt used around a tunnel is dependent on the loads and the integrity of the rock mass around the tunnel.In addition, rock bolting around the tunnel can obviously reduce the coefficients and the size of the region of stress concentration, especially when installed in high-stress areas.This fact is very important and essential for the design of tunnels and ensures engineering safety in tunnel engineering.

  13. Review of Bolt Preload and Torque for Assembling Threaded Fasteners in Nuclear Power Plant

    International Nuclear Information System (INIS)

    There are numerous threaded fasteners such as bolts, studs, nuts, cap screws and anchor bolts used in nuclear power plants(NPPs). The major applications of threaded fasteners are reactor coolant pressure boundary components, their internals and supports. With the increase of commercial operation period of NPPs, the incidents caused by degradation of threaded fasteners have been occurred. A large number of reported incidents are involved in the pressure boundary and major component supports. The degradation and failure of threaded fasteners is affected by material, preload and torque value at assembly, bolting practice, etc. It is very important to select appropriate bolt preload and decide assembly torque value because torque control using a torque wrench is the most common method in a power plant to assemble a bolted flange connection. Many researches have been studied to define the proper bolt preload and desired torque value with regard to the integrity of bolted connections including pressure boundary joints by EPRI and other plant industry. But in domestic NPPs, considerably few works are done on the bolted joint assembly in spite of increasing events related with threaded faster. Therefore we investigated degradation or failure of the threaded fasteners used in NPPs, also examined the codes, standards and technical trends concerning bolt preload and assembly torque in NPPs. It is the purpose of this study to provide proper technical information for assuring integrity of the threaded fasteners

  14. Numerical Studies on Time-Varying Stiffness of Disk-Drum Type Rotor with Bolt Loosening

    Science.gov (United States)

    Qin, Zhaoye; Chu, Fulei

    2015-07-01

    Disk-drum type rotors are widely used in industry for their high stiffness and low weight properties. In disk-drum type rotors, the adjacent disks and drums are commonly connected by bolted joints. Those rotating joint interfaces are subjected to numerous combinations of loads during normal operation, where loosening of the connecting bolts might occur. The bolt loosening will change the local stiffness of the rotor, which in turn affect the rotor dynamics and even result in structural failures. In this paper, the local stiffness of a disk- drum rotor with bolt loosening is investigated numerically. A three-dimensional (3D) finite element (FE) model for the bolted disk-drum joint is established in ANSYS, where the bolt loosening is simulated by reducing the preloads of certain bolts, and removing those bolts as the limiting case. Simulations are performed on the FE model to evaluate the joint behaviour under static loads. Periodic variations of the joint deflections with respect to the rotation angle of the shaft are obtained, which implies the appearance of the time-varying local stiffness in the rotor system. The studies in this paper help accurate prediction of the rotor dynamics and early detection of bolt loosening.

  15. THE PRESENT SITUATION AND DEVELOPMENT OF THE BOLTING AND SHOTCRETING TECHNIQUE IN ROCK TUNNELING

    Institute of Scientific and Technical Information of China (English)

    DUANZhenxi

    1995-01-01

    Application of bolting and shotcreting used in Chinese coal mine underground engineering has been more than 40 years. By the end of 1993. total roadway length adopted bolting and shotcreting was over 21000km. Now, This paper describes developing and achievement of bolting and shotcreting briefly in the recent years. Meanwhile the paper puts forward solving and improving method for problems which exists in present design and construction. Final, combined with feature of coal mine, the paper puts forward some proposals about developing of bolting and shotcreting,dynamic management of both designs and construction, engineering measure and stability judgement as well.

  16. Strength evaluation of aluminium alloy bolt by nano-indentation hardness test

    International Nuclear Information System (INIS)

    A high strength aluminium alloy bolt (A7050, T7 temper treatment) has been developed by the authors. The bolt has a small grain size in the whole area of the bolt because of the large equivalent strain followed by thermo-mechanical treatment. As the bolt made of A7050 has a risk of stress corrosion cracking, to improve the stress corrosion cracking resistance, each grain should be strengthened inside. It has been confirmed that the nano-indentation at each grain inside increased with the increase of the equivalent strain by thermo-mechanical treatment processing (Authors)

  17. Theoretical and experimental research on characteristics of lateral vibration for a pre-stress bolt supporting system

    Institute of Scientific and Technical Information of China (English)

    LI Qing-feng; ZHU Chuan-qu; DUAN Yu

    2009-01-01

    According to the structure and stress trait of bearing bolts,a lateral-vibration mechanics model was established for them,and the relation between lateral-vibration fre-quency and axial load was analyzed; then,lateral-vibration trait of bearing bolts was stud-ied through laboratory simulation test.The results indicate that vibration frequency of bolt support system increases as well as axial force,the detection on axial load of bolts can be made by generating lateral vibration of bearing bolts.Theoretical and experimental re-search results show that frequency method is effective for detecting the axial force of bolt support system.

  18. Knowledge-based support system for requirement elaboration in design

    International Nuclear Information System (INIS)

    Design requirements are the seeds of every design activity, but elicitation and formalization of them are not easy tasks. This paper proposes a method to support designers in such requirement elaboration process with a computer. In this method the cognitive work space of designers is modeled by abstraction and structural hierarchies, and supporting functions of knowledge-based requirement elaboration, requirement classification and assessment of contentment status of requirements are provided on this framework. A prototype system was developed and tested using fast breeder reactor design. (author)

  19. Synthesizing Behavioral Model of Event-Based Requirements

    Directory of Open Access Journals (Sweden)

    Seyyed M. Babamir

    2008-01-01

    Full Text Available Problem Statement: in the software engineering field, satisfaction of user's requirements by software has been a matter of concern. Therefore, monitoring software behavior against user's high-level requirements has already received a considerable and significant attention. However, the gap between low-level software behavior and high-level requirements has put an obstacle in the way of monitoring. Approach: to overcome the obstacle, we presented a method to synthesize a behavioral model of the event-based requirements in three steps: (1 eliciting event-based requirements; (2 specifying the requirements in event-based formulae and (3 mapping the formulae into a behavioral model. Results: to show effectiveness of the method, it was applied to requirements of a safety critical system, called Railroad Crossing Control (RCC one and a behavioral model was synthesized. The model was used to synthesize monitor of the RCC system. The monitor is responsible for surveillance of software behavior for preventing the collision between the train and some car at the junction of rail and road.Conclusions: we proposed a systematic method started from users' requirements elicitation and concluded with its behavioral specification. Focus of the method was on event-based real-time requirements which were stated by scenarios in a sequence of real-time interactions.

  20. Metallurgical examinations update of baffle bolts removed from operating French PWR. Microstructural investigations of a baffle to former bolt located on a high level of the internal structures

    International Nuclear Information System (INIS)

    This paper presents the microstructural investigations conducted on a cracked baffle to former bolt extracted from an upper former level of the internal structures of a French Pressurized Water Reactor (PWR). Extensive microstructural investigations using Light Microscopy, Scanning Electron Microscopy and Transmission Electron Microscopy (TEM) have been conducted to understand the degradation mechanisms of this bolt. TEM investigations have revealed neutron irradiation damage in the microstructure of the bolt such as Frank loops and cavities and/or bubbles. The number of features per unit volume as a function of diameter was determined in the head and in the shank of the bolt. The obtained results are relatively similar to those obtained for other damaged bolts extracted from PWR-type reactors and irradiated in similar conditions (dose and temperature). The irradiation damage has induced an evolution of the mechanical properties (hardening of the material), as revealed by the hardness measurements along the bolt, with a higher average value in the head (400 HV), compared to the shank (15 mm under the head), about 340 HV. The metallurgical investigations have confirmed that this bolt was damaged by Irradiation Assisted Stress Corrosion Cracking (IASCC)

  1. Isolation and identification of an anti-bolting compound, hexadecatrienoic acid monoglyceride, responsible for inhibition of bolting and maintenance of the leaf rosette in radish plants.

    Science.gov (United States)

    Yoshida, Yuko; Takada, Noboru; Koda, Yasunori

    2010-08-01

    Generally, the bolting (stem elongation from rosette plants) of winter annuals is believed to be induced by an increase in the levels of gibberellin that occurs after a certain period of chilling (vernalization), and a deficiency of gibberellin allows the plant to maintain a rosette style. Lack of direct evidence proving the above assumption in radish plants (Raphanus sativus L.) encouraged us to assume the presence of an anti-bolting compound actively maintaining the rosette habit through inhibition of bolting. Anti-bolting activity was detected in an extract of rosette shoots of radish plants by an assay using seedlings cultured in vitro. The causal compound that strongly inhibited bolting was isolated and identified as alpha-(7Z,10Z,13Z)-hexadecatrienoic acid monoglyceride (16:3 monoglyceride). This compound did not inhibit leaf production at the apical meristem, indicating that it merely inhibits growth at the internode. The compound disappeared completely after vernalization, and bolting occurred thereafter. The results suggest that the release from inhibition by 16:3 monoglyceride induces the initiation of bolting. The possible mechanism by which the compound exerts the activity is discussed. PMID:20601431

  2. Classification of Product Requirements Based on Product Environment

    OpenAIRE

    Chen, Zhen Yu; Zeng, Yong

    2006-01-01

    Abstract Effective management of product requirements is critical for designers to deliver a quality design solution in a reasonable range of cost and time. The management depends on a well-defined classification and a flexible representation of product requirements. This article proposes two classification criteria in terms of different partitions of product environment based on a formal structure of produ...

  3. Knowledge-based requirements analysis for automating software development

    Science.gov (United States)

    Markosian, Lawrence Z.

    1988-01-01

    We present a new software development paradigm that automates the derivation of implementations from requirements. In this paradigm, informally-stated requirements are expressed in a domain-specific requirements specification language. This language is machine-understable and requirements expressed in it are captured in a knowledge base. Once the requirements are captured, more detailed specifications and eventually implementations are derived by the system using transformational synthesis. A key characteristic of the process is that the required human intervention is in the form of providing problem- and domain-specific engineering knowledge, not in writing detailed implementations. We describe a prototype system that applies the paradigm in the realm of communication engineering: the prototype automatically generates implementations of buffers following analysis of the requirements on each buffer.

  4. Proposing an Evidence-Based Strategy for Software Requirements Engineering.

    Science.gov (United States)

    Lindoerfer, Doris; Mansmann, Ulrich

    2016-01-01

    This paper discusses an evidence-based approach to software requirements engineering. The approach is called evidence-based, since it uses publications on the specific problem as a surrogate for stakeholder interests, to formulate risks and testing experiences. This complements the idea that agile software development models are more relevant, in which requirements and solutions evolve through collaboration between self-organizing cross-functional teams. The strategy is exemplified and applied to the development of a Software Requirements list used to develop software systems for patient registries. PMID:27577464

  5. INJECTION MOLDING AND STRUCTURAL ANALYSIS IN METAL TO PLASTIC CONVERSION OF BOLTED FLANGE JOINT BY CAE

    Directory of Open Access Journals (Sweden)

    Marian Blaško

    2014-12-01

    Full Text Available Many metal parts in various applications are being replaced by plastic parts. There are several reasons for that depending on actual application - minimize part cost, enhance corrosion resistance, integrating more components into one part etc. Most important steps of metal to plastic conversion are material selection and design of plastic part. Plastic part has to withstand the same load as metal part. To fulfill this requirement fiber reinforced engineering plastics are often used. Also it is convenient to substitute heavy wall sections with ribbed structure to increase load-carrying ability of part and decrease cycle time, eliminate voids, sink marks etc. Mechanical properties of such part could be highly affected by fiber orientation. Results of fiber orientation from injection molding filling analysis can be used in stress analysis for better prediction of part response to mechanical load. Such coupled analysis is performed here in this case study on bolted flange joint.

  6. Stress evaluation of baffle former bolt for IASCC failure prediction

    International Nuclear Information System (INIS)

    Baffle structure in PWRs Reactor is quite important assembly for the core safety, and Baffle Former Bolts (BFBs) are fastener members for maintaining Baffle structure. It has been reported worldwide that some of BFBs were cracked due to IASCC (Irradiation Assisted Stress Corrosion Cracking) because BFBs are located at core region under severe environments, high neutron flux, high temperature and high stress. According to the material studies of IASCC on austenitic stainless steel, a crack initiation of IASCC is strongly related with the stress and the neutron fluence. For this reason, it is very important for IASCC failure prediction to simulate the stress of BFBs. However, the stress of BFBs are considered to be influenced by several factors and to be changed complexly as operational time increases, by irradiation creep of Bolt itself, swelling of Baffle structure, and so on. Therefore, it is difficult to estimate the stress histories of BFBs (Bolt stress as a function of operational time) precisely. Then, the author has developed the calculation method of the stress histories of BFBs considering irradiation effects (swelling and irradiation creep). In this method, the stress histories of BFBs are calculated by combining two kinds of FE models, Global model (modeled whole Baffle structure which consists of Baffle plates, Former plates and Core Barrel) and Local model (modeled around BFB finely). The whole Baffle structure deformation changes as a function of heat, swelling and irradiated creep are calculated by Global model, and the stress histories of BFBs are calculated by Local model using the outputs (deformations on driving nodes) of Global model. In the FE analysis of Local model, the stress of BFBs are calculated considering irradiation effects and elastic-plastic characteristics depending on neutron fluence, so this method enables to calculate precisely the stress of extreme small area of BFBs surface. This paper shows the outline of the calculation method

  7. Improvement activities for the maintenance of Baffle Former Bolts

    International Nuclear Information System (INIS)

    Baffle Former Bolts (BFBs) in PWR nuclear plant have the possibility to be cracked due to Irradiation Assisted Stress Corrosion Cracking (IASCC). The maintenance guideline for BFBs had been established from Thermal and Nuclear Power Engineering Society in 2000, and BFBs have been maintained in accordance with this maintenance rules. Recently, the new edition of this guideline has been published in order to reflect latest IASCC data and more precise stress evaluation of BFB into maintenance rules. The summary of the revised contents and these improvement activities are introduced in this paper. (author)

  8. Lightning Bolt: an ecology of imagens, noises and extremes sounds

    Directory of Open Access Journals (Sweden)

    Fabrício Lopes da Silveira

    2011-12-01

    Full Text Available The article is focused exclusively on the music video “Dracula Mountain”, by north American noise-rock band Lightning Bolt. The aim is, in fact, sufficiently restricted: to describe the video and call it in question, considering it as a counterpoint to the band sonority and musical performance. At the end, we state that the video is both a symptom and a product of a very particular and contemporary media ecology, in which musical and audiovisual products and genres, as well as musical and audiovisual consumption habits are rebuilt and (repotentialized, sometimes inverted.

  9. Hydraulic nuts (HydraNuts) for critical bolted joints

    International Nuclear Information System (INIS)

    HydraNuts replace the original nut and torquing equipment, combining the two functions into one system. Designed for simple installation and operation. HydraNuts are fitted to the stud bolts. Once all HydraNuts are fitted to the application, flexible hydraulic hoses are connected, forming a closed loop hydraulic harness, allowing simultaneous pressurization of all HydraNuts. Hydraulic pressure is obtained by the use of a pumping unit and the resultant load generated is transferred to the studs and flange closure is obtained. Locking rings are rotated into place, supporting the tensioned load mechanically after hydraulic pressure is released. The hose harness is removed. (author)

  10. Resolution of Generic Safety Issue 29: Bolting degradation or failure in nuclear power plants

    International Nuclear Information System (INIS)

    This report describes the US Nuclear Regulatory Commission's (NRC's) Generic Safety Issue 29, ''Bolting Degradation or Failure in Nuclear Power Plants,'' including the bases for establishing the issue and its historical highlights. The report also describes the activities of the Atomic Industrial Forum (AIF) relevant to this issue, including its cooperation with the Materials Properties Council (MPC) to organize a task group to help resolve the issue. The Electric Power Research Institute, supported by the AIF/MPC task group, prepared and issued a two-volume document that provides, in part, the technical basis for resolving Generic Safety Issue 29. This report presents the NRC's review and evaluation of the two-volume document and NRC's conclusion that this document, in conjunction with other information from both industry and NRC, provides the bases for resolving this issue

  11. Verifying real-time systems against scenario-based requirements

    OpenAIRE

    Larsen K.G.; Li S; Nielsen B; Pusinskas S.

    2009-01-01

    We propose an approach to automatic verification of real-time systems against scenario-based requirements. A real-time system is modeled as a network of Timed Automata (TA), and a scenario-based requirement is specified as a Live Sequence Chart (LSC). We define a trace-based semantics for a kernel subset of the LSC language. By equivalently translating an LSC chart into an observer TA and then non-intrusively composing this observer with the original system model, the problem of verifying a r...

  12. Device for distance welding of bolts with a remote controlled gun

    International Nuclear Information System (INIS)

    The welding gun includes two grounded contacts, on each side of the bolt to weld. They are mounted on springs for a better electric contact with the surface to be welded to the bolts. Remote control of the welding unit is provided for working where there is a radiation risk

  13. Enhancement of crack detection in stud bolts of nuclear reactor by ultrasonic technique

    International Nuclear Information System (INIS)

    The stud bolt is one of crucial parts for safety of reactor vessels in nuclear power plants. Crack initiation and propagation were reported in stud bolts using closure of reactor vessel and head. Stud bolts are inspected by ultrasonic technique during overhaul periodically for the prevention of stud bolt failure and radioactive leakage from nuclear reactor. In conventional ultrasonic testing for inspection of stud bolts, crack was detected by using shadow effect. It takes too much time to inspect stud bolt by using conventional ultrasonic technique. In addition, there were numerous spurious signals reflected from every oblique surfaces of thread. In this study, the signal processing technique for enhancing conventional ultrasonic technique and the advanced ultrasonic phased array technique were introduced for inspect stud bolts. The signal processing technique provides removing spurious signal reflected from every oblique surfaces of thread and enhances detectability of defects. The phased array technique provides fast inspection and can be applied for structure of complex shape. There are sector scanning and linear scanning methods in phased array technique, and these scanning methods were applied to inspect stud bolt and detectability was investigated. (author)

  14. Monitoring bolt torque levels through signal processing of full-field ultrasonic data

    Science.gov (United States)

    Haynes, Colin; Yeager, Michael; Todd, Michael; Lee, Jung-Ryul

    2014-03-01

    Using full-field ultrasonic guided wave data can provide a wealth of information on the state of a structure through a detailed characterization of its wave propagation properties. However, the need for appropriate feature selection and quantified metrics for making rigorous assessments of the structural state is in no way lessened by the density of information. In this study, a simple steel bolted connection with two bolts is monitored for bolt loosening. The full-field data were acquired using a scanning-laser-generated ultrasound system with a single surface-mounted sensor. Such laser systems have many advantages that make them attractive for nondestructive evaluation, including their high-speed, high spatial resolution, and the ability to scan large areas of in-service structures. In order to characterize the relationship between bolt torque and the resulting wavefield in this specimen, the bolt torque in each of the bolts is independently varied from fully tightened to fully loosened in several steps. First, qualitative observations about the changes in the wavefield are presented. Next, an approach to quantifying the wave transmission through the bolted joint is discussed. Finally, a method of monitoring the bolt torque using the ultrasonic data is demonstrated.

  15. Failure Analysis of Bolts%螺钉失效分析

    Institute of Scientific and Technical Information of China (English)

    吴伟

    2001-01-01

    对断裂螺钉的断口观察,分析了螺钉的装配情况,找出了断裂原因。%On the basis of observation of the ruptured section of a bolt, the author analyzes the assembled condition of the bolt. As a result, the rupture reason is found out.

  16. The Nuts and Bolts of Michaelis-Menten Enzyme Kinetics: Suggestions and Clarifications

    Science.gov (United States)

    Silverstein, Todd

    2011-01-01

    Matthew Junker's recent article describes a useful and effective enzyme kinetics application and analogy in which students simulate enzyme activity by unscrewing nut-bolt "substrate molecules", thus, converting them into separate nuts and bolts "products". A number of suggestions and corrections are presented that improve the clarity and accuracy…

  17. Fasteners 1 dimensional standards for bolts, screws and studs national standards

    CERN Document Server

    2011-01-01

    This 7th edition of DIN Handbook 10 contains 90 currently valid German national standards (DIN Standards) dealing with the dimensions of bolts, screws and studs. In this updated compilation four standards are new: DIN 787 T-head bolts; DIN 1445 Clevis pins with head and threaded portion; DIN 5903-1 Fish bolts - Part 1: With round head and oval neck; DIN 5903-2 Fish bolts - Part 2: With square head. 27 standards have been revised for this edition. DIN Handbook 10 is the companion volume to DIN Handbook 362 "Fasteners 6 - Dimensional standards for bolts and screws - European Standards", which reflects the state of the art in Europe. Together, DIN Handbooks 10 and 362 provide the user with a comprehensive overview of standards in the fasteners sector.

  18. Effects of sowing time on bolting and returning green in welsh onion

    Institute of Scientific and Technical Information of China (English)

    JI Jiaojiao; LIU Jing; XING Xiaoxue; JIANG Xinmei

    2007-01-01

    Qiyechangbai and Hadacongl were used to study the relationship of the leaf age of overwinter to bolting and returning green by the difference of sowing time. The results showed that the earlier the seeds were sown, the older leaf age of overwinter was, the higher the rates of returning green and bolting rate were, the earlier the bolting time was. The leaf age of overwinter of Qiyechangbai sown August 31 to September 14 was 2.1-3.1 leaves and the rate of returning green was 86.5%-92.1%, while the leaf age of overwinter of Hadacongl sown September 7 to September 14 was 2.3-2.7 leaves and the rate of returning green was 88.5%-93.8%, both varieties didn't bolt. In addition, in the same sowing time, the bolting rate of Hadacong1 was higher than that of Qiyechangbai slightly.

  19. A critical flaw size approach for predicting the strength of bolted glass connections

    DEFF Research Database (Denmark)

    Watson, James; Nielsen, Jens Henrik; Overend, Mauro

    2013-01-01

    The use of bolted connections in glass installations is common place in contemporary architecture. However, it is difficult to predict the load bearing capacity of these connections accurately due to the several factors that influence the strength of glass in the region of the bolt hole, namely......: the complex stress state, the inherent strength of glass and the magnitude of residual thermal stresses. This paper proposes a critical flaw size approach for bolted connections. The approach uses a numerical tempering model and nonlinear finite element analysis to determine the sizes of the critical...... flaws around the bolt hole, from destructive tests on bolted glass components subjected to in-plane loading. The critical flaw sizes determined by this approach agree with the flaw sizes obtained from optical microscopy. These flaw sizes are subsequently used to plot lifetime prediction curves for the...

  20. Experimental and Numerical Investigation of an End Plate Connection with Using Long Shank SMA Bolts

    Institute of Scientific and Technical Information of China (English)

    Hongwei Ma; Yongbing Zhu; Michael CH Yam; Yang Wang

    2015-01-01

    Superelastic shape memory alloys ( SMAs ) have the ability to recover their original shape after experiencing large strains. End⁃plate connection with using superelastic long shank SMA bolts is proposed in this paper. By using strong beam⁃weak bolt cluster design methodology and special configurations to strength beam ends, a superelastic hinge is expected to form in column flange. To validate the mechanical behavior of the proposed beam⁃to⁃column connection, both quasi⁃static tests and numerical analysis are conducted with cyclic transverse loads applied on the beam ends. The results indicate the connection deformations concentrate on the long shank SMA bolts upon loading and the bolt cluster rotates around the axis near beam flange. By using the super elastic effect, the SMA bolts recover most elongations and the connection recovers to its original shape after experiencing 0�02 rad interstorey drift angle. The connection shows obvious self⁃centering properties.

  1. Requirements Engineering Model: Role Based Goal Oriented Model

    OpenAIRE

    Sandfreni; Surendro Ir. Kridanto

    2016-01-01

    Requirements engineering approach through intentional perspective is one of the arguments that appear in the field of requirement engineering. That approach can explain the characteristics of the behavior of an actor. The usage Goal Based Workflow and KAOS method in iStar modeling might help the system analyst to gain knowledge about the internal process inside each of actor sequentially, such that the whole sequential activity to achieve the goal are exposed clearly in those actor’s internal...

  2. Performance of bolted closure joint elastomers under cask aging conditions

    Energy Technology Data Exchange (ETDEWEB)

    Verst, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Sindelar, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Skidmore, E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Daugherty, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-07-23

    The bolted closure joint of a bare spent fuel cask is susceptible to age-related degradation and potential loss of confinement function under long-term storage conditions. Elastomeric seals, a component of the joint typically used to facilitate leak testing of the primary seal that includes the metallic seal and bolting, is susceptible to degradation over time by several mechanisms, principally via thermo-oxidation, stress-relaxation, and radiolytic degradation under time and temperature condition. Irradiation and thermal exposure testing and evaluation of an ethylene-propylene diene monomer (EPDM) elastomeric seal material similar to that used in the CASTOR® V/21 cask for a matrix of temperature and radiation exposure conditions relevant to the cask extended storage conditions, and development of semiempirical predictive models for loss of sealing force is in progress. A special insert was developed to allow Compressive Stress Relaxation (CSR) measurements before and after the irradiation and/or thermal exposure without unloading the elastomer. A condition of the loss of sealing force for the onset of leakage was suggested. The experimentation and modeling being performed could enable acquisition of extensive coupled aging data as well as an estimation of the timeframe when loss of sealing function under aging (temperature/radiation) conditions may occur.

  3. Modeling and simulation of Polymer Composite laminate bolted Joint

    Directory of Open Access Journals (Sweden)

    B. Sutharson

    2013-10-01

    Full Text Available Environmental awareness today motivates the researchers, worldwide on the studies of natural fiber reinforced polymer composite and cost effective option to synthetic fiber reinforced composites. This work is concerned with the modeling and simulation of bearing properties of hybrid fiber polymer composite mechanical joint using Artificial Neural Network (ANN. In general it was found that increase in bearing capacity was always with increasing the e/d and w/d ratio. However, the extent of increase/decrease depends on the type of stacking sequence. There was increase in strength with rise in natural fiber loading. In this study, an artificial neural network is developed to predict the response of bolt-loaded fiber reinforced polymer composite plates. To predict the behavior of the laminate failure, a multilayered feed-forward neural network trained with the back-propagation algorithm is constructed. The ANN was trained and verified using experimental data. Comparisons of ANN results with desired values showed that there is a good agreement between input and output variables of the experimental data. The results indicate that ANN was illustrated to be a valid useful and powerful tool for the prediction of bearing properties predictions of bolted joints in composite laminates.

  4. Babcock ampersand Wilcox experience with alloy A-286 reactor vessel internal bolting

    International Nuclear Information System (INIS)

    Multiple reactor vessel internal bolt failures were discovered during the 1981 and 1982 in service inspections performed at three PWR nuclear power plants. All the failures were limited to bolts that fastened the lower portion of the reactor vessel internal thermal shield to the lower grid assembly. Subsequent examinations during 1982, 1983 and 1984 revealed bolt failures at four additional plants. These failures included bolts that fastened the core barrel to the core support shield and lower grid assembly. Additional failures were also discovered in the bolts used to join the surveillance specimen holder tube to the thermal shield. All the affected fasteners were fabricated from Alloy A-286 (ASTM A453 Grade 660) material. Alloy A-286 is a high strength precipitation hardened austenitic stainless steel containing a nominal Cr and Ni content of 15% and 25%, respectively. As a result of these bolt failures, the Babcock ampersand Wilcox Co., under the direction of the B ampersand W Owners Group, performed extensive evaluations of Alloy A-286 reactor vessel internal fasteners. The principal conclusions obtained from this investigation are given below. 1. Internals bolting failures have been observed at nominal peak calculated stress levels of greater than or equal to 690 MPa (100 ksi). The number of failures generally increases with increasing stress. Variations in this correlation are postulated to be the result of scatter in the calculated peak stress data. 2. A variety of material conditions including the use of highly cold worked barstock in the fabrication of some of the bolts, degree of annealing and hot forging may have contributed to the bolt failures. 3. No specific upset environmental conditions were found that could be judged to be a leading cause of the bolt failures. 4 refs., 2 tabs

  5. A practical approach to object based requirements analysis

    Science.gov (United States)

    Drew, Daniel W.; Bishop, Michael

    1988-01-01

    Presented here is an approach developed at the Unisys Houston Operation Division, which supports the early identification of objects. This domain oriented analysis and development concept is based on entity relationship modeling and object data flow diagrams. These modeling techniques, based on the GOOD methodology developed at the Goddard Space Flight Center, support the translation of requirements into objects which represent the real-world problem domain. The goal is to establish a solid foundation of understanding before design begins, thereby giving greater assurance that the system will do what is desired by the customer. The transition from requirements to object oriented design is also promoted by having requirements described in terms of objects. Presented is a five step process by which objects are identified from the requirements to create a problem definition model. This process involves establishing a base line requirements list from which an object data flow diagram can be created. Entity-relationship modeling is used to facilitate the identification of objects from the requirements. An example is given of how semantic modeling may be used to improve the entity-relationship model and a brief discussion on how this approach might be used in a large scale development effort.

  6. 1300 MPa High Strength Steel for Bolt with Superior Delayed Fracture Resistance

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By the increase in Mo content, the addition of microalloying elements V and Nb and by reducing the contents of Mn, P and S based on the composition of steel 42CrMo, we have developed a 1300 MPa-grade high strength steel (ADF1) for bolts. The sustained load bending test, sustained load tensile test and stress corrosion cracking test have been carried out to evaluate the delayed fracture resistance of steel ADF1 and commercial steel 42CrMo. The results showed that steel ADF1 has superior delayed fracture resistance to that of 42CrMo steel. It's concluded that the superior delayed fracture resistance of ADF1 is mainly due to the increase of tempering temperature, fine homogeneously distributed MC carbide and fine prior austenite grain size.

  7. NVC Based Model for Selecting Effective Requirement Elicitation Technique

    Directory of Open Access Journals (Sweden)

    Md. Rizwan Beg

    2012-10-01

    Full Text Available Requirement Engineering process starts from gathering of requirements i.e.; requirements elicitation. Requirementselicitation (RE is the base building block for a software project and has very high impact onsubsequent design and builds phases as well. Accurately capturing system requirements is the major factorin the failure of most of software projects. Due to the criticality and impact of this phase, it is very importantto perform the requirements elicitation in no less than a perfect manner. One of the most difficult jobsfor elicitor is to select appropriate technique for eliciting the requirement. Interviewing and Interactingstakeholder during Elicitation process is a communication intensive activity involves Verbal and Nonverbalcommunication (NVC. Elicitor should give emphasis to Non-verbal communication along with verbalcommunication so that requirements recorded more efficiently and effectively. In this paper we proposea model in which stakeholders are classified by observing non-verbal communication and use it as a basefor elicitation technique selection. We also propose an efficient plan for requirements elicitation which intendsto overcome on the constraints, faced by elicitor.

  8. NRC Information No. 88-42: Circuit breaker failures due to loose charging spring motor mounting bolts

    International Nuclear Information System (INIS)

    There are two emergency diesel generators (EDGs) at North Anna Unit 2 (H and J). On May 19, 1988, following completion of scheduled preventive maintenance, the ''J'' EDG failed to pick up and carry the required load during preoperational testing. The licensee then shut down the ''J'' EDG and performed unplanned corrective maintenance. The licensee's technical specifications require that the operable EDG be tested within 24 hours if the inoperable EDG is inoperable due to any cause other than preplanned preventive maintenance or testing; thus, because of the unplanned maintenance on the ''J'' EDG the licensee tested the ''H'' EDG. During this test, the ''J'' EDG output circuit breaker (ITE Type 5HK) failed to close. The licensee's investigation determined that the ''H'' EDG output breaker closing spring had not been charged because the charging spring motor mounting bolts had become loose, allowing the motor to become detached from the frame. A similar occurrence was previously reported by Philadelphia Electric Company (the Limerick Units 1 and 2 licensee) on August 27, 1984. During an EDG preoperational test, the charging spring motor of a BBC Brown Boveri, Inc. 5HK breaker failed to perform its intended function. The licensee determined that three out of four horizontal charging spring motor mounting bolts had loosened, allowing the charging spring motor to rotate. Loose charging spring motor mounting bolts may be a generic concern. Because of changes in corporate name, mergers etc., circuit breakers similar to those discussed may indicate manufacture by ITE, ITE Imperial, Gould, Brown Boveri, or a combination thereof

  9. Failure behavior for composite single-bolted joints in double shear tension

    Science.gov (United States)

    Tang, Zhanwen; Liu, Hanyang; Yang, Zhiyong; Shi, Hanqiao; Sun, Baogang

    2016-05-01

    In order to improve the reliability and load carrying capacity of composite laminates structures which were lap jointed by bolt, in this paper, the failure strength and failure mode of laminated composite pinned-joints is investigated. To determine the effects of joint geometry and stacking sequence on the bearing strength and damage mode, the multi-scale numerical model combining with the Generalized Method of Cells (GMC) and considering the failure and the damage of constituent materials was created based on the ABAQUS and its user subroutine (USDFLD). A three-dimensional finite element technique was used for the stress analysis. Based on the three-dimensional state of stress of each element, different failure modes were detected by the failure theories of constituent materials, all of which are applied at the fiber, matrix and fiber-matrix interface constituent level. Numerical simulations have been carried out by which edge distance-to-hole diameter ratio, and plate width-to-hole diameter ratio are varied, The composite laminated plates are stacked with the following four different orientations: [+45/-45]2s, [90/+45/-45]s, and [0/90/0]s, the results show that failure mode and bearing strength are closely related to by stacking sequence of plates and geometrical parameters. Finally, the ultimate strength and failure modes of composite bolted joints in static tension double-shear loading conditions are predicted by using the progressive damage method established and the effects of layup and dimension of laminates on the properties of the connection structure were researched in this paper. An excellent agreement is found between data obtained from this study and the experiment.

  10. ICON-BASED LANGAUGE: AUXILIARY COMMUNICATION FOR REQUIREMENTS ENGINEERING

    Directory of Open Access Journals (Sweden)

    SUKANYA KHANOM

    2013-05-01

    Full Text Available In requirements engineering, numerous modelling approaches have been addressed to support communication and shared understanding, for instance, UML (use case diagram and GORE (goal graph. Most of them use abstract geometrical shapes as fundamental elements. The RE stakeholders, therefore, need to master the prerequisite skill to understand this complex set of abstraction. Recently, there has been an increasing need for a simple and an easy-to-learn modelling technique. We propose an icon-based language as an alternative to REmodelling. Unlike other RE notations, icon-based language is devised principally from a set of icons. Our approach can be derived by identifying RE world, defining icon world and combining these two worlds. This development yields the demand to have a modelling language that unifies requirements activities. The result can be used to overcome the communication barriers between technical and non-technical stakeholders, and to have icon attributes that can be attached to individual requirement.

  11. Fusing Quantitative Requirements Analysis with Model-based Systems Engineering

    Science.gov (United States)

    Cornford, Steven L.; Feather, Martin S.; Heron, Vance A.; Jenkins, J. Steven

    2006-01-01

    A vision is presented for fusing quantitative requirements analysis with model-based systems engineering. This vision draws upon and combines emergent themes in the engineering milieu. "Requirements engineering" provides means to explicitly represent requirements (both functional and non-functional) as constraints and preferences on acceptable solutions, and emphasizes early-lifecycle review, analysis and verification of design and development plans. "Design by shopping" emphasizes revealing the space of options available from which to choose (without presuming that all selection criteria have previously been elicited), and provides means to make understandable the range of choices and their ramifications. "Model-based engineering" emphasizes the goal of utilizing a formal representation of all aspects of system design, from development through operations, and provides powerful tool suites that support the practical application of these principles. A first step prototype towards this vision is described, embodying the key capabilities. Illustrations, implications, further challenges and opportunities are outlined.

  12. Innovative Product Design Based on Customer Requirement Weight Calculation Model

    Institute of Scientific and Technical Information of China (English)

    Chen-Guang Guo; Yong-Xian Liu; Shou-Ming Hou; Wei Wang

    2010-01-01

    In the processes of product innovation and design, it is important for the designers to find and capture customer's focus through customer requirement weight calculation and ranking. Based on the fuzzy set theory and Euclidean space distance, this paper puts forward a method for customer requirement weight calculation called Euclidean space distances weighting ranking method. This method is used in the fuzzy analytic hierarchy process that satisfies the additive consistent fuzzy matrix. A model for the weight calculation steps is constructed;meanwhile, a product innovation design module on the basis of the customer requirement weight calculation model is developed. Finally, combined with the instance of titanium sponge production, the customer requirement weight calculation model is validated. By the innovation design module, the structure of the titanium sponge reactor has been improved and made innovative.

  13. Building a Narrative Based Requirements Engineering Mediation Model

    Science.gov (United States)

    Ma, Nan; Hall, Tracy; Barker, Trevor

    This paper presents a narrative-based Requirements Engineering (RE) mediation model to help RE practitioners to effectively identify, define, and resolve conflicts of interest, goals, and requirements. Within the SPI community, there is a common belief that social, human, and organizational issues significantly impact on the effectiveness of software process improvement in general and the requirements engineering process in particularl. Conflicts among different stakeholders are an important human and social issue that need more research attention in the SPI and RE community. By drawing on the conflict resolution literature and IS literature, we argue that conflict resolution in RE is a mediated process, in which a requirements engineer can act as a mediator among different stakeholders. To address socio-psychological aspects of conflict in RE and SPI, Winslade and Monk (2000)'s narrative mediation model is introduced, justified, and translated into the context of RE.

  14. Flow-Based Specification of Time Design Requirements

    Directory of Open Access Journals (Sweden)

    Sabah Al-Fedaghi

    2015-08-01

    Full Text Available This paper focuses on design requirements in real-time systems where information is processed to produce a response within a specified time. Nowadays, computer control applications embedded in chips have grown in significance in many aspects of human life. These systems need a high level of reliability to gain the trust of users. Ensuring correctness in the early stages of the design process is especially a major challenge in these systems. Faulty requirements lead to errors in the final product that have to be fixed later, often at a high cost. A crucial step in this process is modeling the intended system. This paper explores the potential of flow-based modeling in expressing design requirements in real-time systems that include time constraints and synchronization. The main emphasized problem is how to represent time. The objective is to assist real-time system requirement engineers, in an early state of the development, to express the timing behavior of the developed system. Several known examples are modeled and the results point to the viability of the flow-based representation in comparison with such time specifications as state-based and line-based modeling.

  15. Numerical simulation of attenuation and group velocity of guided ultrasonic wave in grouted rock bolts

    Science.gov (United States)

    Cui, Y.; Zou, D. H.

    2006-08-01

    In this paper, the guided ultrasonic wave propagating in grouted rock bolts was simulated with finite element method. An 800 mm partially grouted cylindrical rock bolt model was created. Dynamic input signals with frequency from 25 to 100 kHz were used to excite ultrasonic wave. The simulated waveform, group velocity and amplitude ratio matched well with the experimental results. This model made it possible to study the behaviour of the guided waves in the grouted bolt along its central axis. Analysis of the simulated results showed that the group velocity in grouted rock bolts is constant along the grouted length, and the boundary effect on the group velocity is negligible. This paper also presents methods to determine the attenuation coefficient from simulation and to determine the boundary effect on attenuation at the bolt ends. The analysis showed that the attenuation of the guided wave propagating inside the grouted bolts is similar to the theoretical solution in steel bar with infinite length. After correction for the boundary effects the grout length of a grouted rock bolt can be determined using the measured attenuation, with sufficient accuracy.

  16. Corrosion and stress corrosion cracking of bolting materials in light water reactors

    International Nuclear Information System (INIS)

    The primary coolant of a pressurized water reactor contains dissolved boric acid added as a soluble neutron absorber. Corrosion and stress corrosion cracking of bolts on pumps and on primary system manways have occurred where gaskets leak this boric acid onto the low alloy steel bolting material. Laboratory experiments have shown that the concentration of the boric acid to a moist paste at approximately the boiling point of water can produce corrosion rates of the order of several tenths of an inch per year on bolting and piping materials, which values are consistent with service experience. Frequently molybdenum disulfide is used as a lubricant for tightening bolts on massive flanges. Laboratory experience has shown that when the primary coolant leaks through a gasket the molybdenum disulfide can react with the leaking steam to produce hydrogen sulfide and subsequent stress corrosion cracking of the bolts. Additionally, contaminants concentrating over significant time periods have caused stress corrosion cracking failures of reactor coolant pump internals. Failure analysis of cracked bolts from service and the results of laboratory tests that demonstrate these mechanisms of bolt cracking are presented

  17. 连杆螺栓的强度分析%Strength Analysis for Connecting Rod Bolt

    Institute of Scientific and Technical Information of China (English)

    李笑岩; 付冰洋; 张建云; 张士永

    2016-01-01

    对连杆螺栓受力进行了研究,利用ANSYS对螺栓进行静力学分析,得出螺栓的应力分布状况。对连杆螺栓断裂事故进行了分析,得出可能造成螺栓断裂的原因;利用Miner疲劳损伤理论和ANSYS软件,分别对连杆螺栓进行疲劳寿命计算,预估螺栓的使用寿命。%The force of the connecting rod bolts is researched in the paper. Using ANSYS software, static analysis of connecting rod bolts is calculated. And the stress distribution of connecting rod bolts is got from ANSYS. The accident that the connecting rod bolts broken is analyzed and the reason for the bolt fracture is obtained. Using Miner Fatigue Damage Theory and ANSYS software, the fa-tigue life of connecting rod bolt is calculated and the using life of bolt is estimated.

  18. A Study on the Fracture Control of Rock Bolts in High Ground Pressure Roadways of Deep Mines

    Directory of Open Access Journals (Sweden)

    Wen Jinglin

    2015-01-01

    Full Text Available According to the frequent fractures of rock bolts in high ground pressure roadways of deep mines, this paper analyzes the mechanism of fractures and concludes that high ground pressure and material de-fects are main reasons for the fracture of rock bolts. The basic idea of fracture control of rock bolts in high ground pressure roadways of deep mines is to increase the yield load and the limit load of rock bolt materials and reduce the actual load of rock bolts. There are four ways of controlling rock bolt fracture: increasing the rock bolt diameter, strengthening bolt materials, weakening support rigidity and the implementation of double supporting. With the roadway support of the 2302 working face of a coal mine as the project background, this paper carries out a study on the effect of two schemes, increasing the rock bolt diameter and the double supporting technique through methods of theoretical analysis, numerical simulation and so on. It determines the most reasonable diam-eter of rock bolts and the best delay distance of secondary support. Practices indicate that rock bolt fracture can be effectively controlled through the double supporting technique, which strengthens the roof and two sides through the first supporting technique and strengthens side angles through the secondary supporting technique.

  19. Stress state and caving danger of the roof in bolt supporting roadway

    Institute of Scientific and Technical Information of China (English)

    LIU Shao-wei; XU Li-li

    2006-01-01

    The start point of this text is the bottleneck problem of bolt supporting coal entry that is security problem of bolt supporting roof,we divide one entry into some sections with different stress, simulate stress field of wall rock and rockbolt solidified at different sections used umbrella disperse soft UDEC(universal distinct element code), we educe that the stress level of wallrock and bolt solidified is higher in roof fall risk section, and roof rockbolt load can reflect this rule clearly, that offer an important guideline in monitoring entry roof fall risk.

  20. Research on coal roadway truss and numerical simulation of bolting support effect

    Institute of Scientific and Technical Information of China (English)

    NING Jian-guo; ZHANG Xin-guo; GAO Ming-tao

    2007-01-01

    According to the research results in world, the paper comprehensively analyzed and gave a demonstration of mechanism of single-truss and its stressing advantage. Comparison and analysis effect were given to single-truss and bolting supporting. By the way of element simulation. The paper shows that single truss supporting have better effect to bolting supporting to improving the stress condition of surrounding rocks, controlling the surrounding rocks plastic failure development zone and deformation effect of surrounding rocks, which provided the elementary theory basis to the research, experiment and expanding the single-truss bolting technology in colliery.

  1. FRAMEWORK-BASED DATA REQUIREMENTS FOR IT TOP MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Virpi Hotti

    2014-09-01

    Full Text Available There are several challenges on the adoptions of the frameworks (e.g., standards. If the main target is semantic interoperability, then data should be taken into consideration. The main aim of this paper is to identify some mechanisms that take closer to the semantic interoperability. Therefore, the framework-based lessons for top management are based on the asset management standard (ISO 55001:2014 where data are one type of assets and enterprise architecture metamodel (TOGAF content metamodel. The results establish that none of the asset management requirements for top management mentions data and the attributes of the data entity do not support the semantics interoperability.

  2. Simulation-based assessment in anesthesiology: requirements for practical implementation.

    Science.gov (United States)

    Boulet, John R; Murray, David J

    2010-04-01

    Simulations have taken a central role in the education and assessment of medical students, residents, and practicing physicians. The introduction of simulation-based assessments in anesthesiology, especially those used to establish various competencies, has demanded fairly rigorous studies concerning the psychometric properties of the scores. Most important, major efforts have been directed at identifying, and addressing, potential threats to the validity of simulation-based assessment scores. As a result, organizations that wish to incorporate simulation-based assessments into their evaluation practices can access information regarding effective test development practices, the selection of appropriate metrics, the minimization of measurement errors, and test score validation processes. The purpose of this article is to provide a broad overview of the use of simulation for measuring physician skills and competencies. For simulations used in anesthesiology, studies that describe advances in scenario development, the development of scoring rubrics, and the validation of assessment results are synthesized. Based on the summary of relevant research, psychometric requirements for practical implementation of simulation-based assessments in anesthesiology are forwarded. As technology expands, and simulation-based education and evaluation takes on a larger role in patient safety initiatives, the groundbreaking work conducted to date can serve as a model for those individuals and organizations that are responsible for developing, scoring, or validating simulation-based education and assessment programs in anesthesiology. PMID:20234313

  3. A Reduced Order Model of Force Displacement Curves for the Failure of Mechanical Bolts in Tension.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Keegan J. [Univ. of Illinois, Urbana-Champaign, IL (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brake, Matthew Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    Assembled mechanical systems often contain a large number of bolted connections. These bolted connections (joints) are integral aspects of the load path for structural dynamics, and, consequently, are paramount for calculating a structure's stiffness and energy dissipation prop- erties. However, analysts have not found the optimal method to model appropriately these bolted joints. The complexity of the screw geometry causes issues when generating a mesh of the model. This report will explore different approaches to model a screw-substrate connec- tion. Model parameters such as mesh continuity, node alignment, wedge angles, and thread to body element size ratios are examined. The results of this study will give analysts a better understanding of the influences of these parameters and will aide in finding the optimal method to model bolted connections.

  4. Fewer complications with bolt-connected than tunneled external ventricular drainage

    DEFF Research Database (Denmark)

    Jensen, Torben Slott; Carlsen, Jakob Gram; Sørensen, Jens Christian;

    2016-01-01

    BACKGROUND: Ventriculostomy/external ventricular drain (EVD) is a common neurosurgical procedure. Various techniques are used to fixate the drain and the objective of this study was, in a retrospective setting, to compare the incidence of complications when using bolt-connected EVD (BC-EVD) versus...... tunneled EVD (T-EVD). METHODS: All patients subjected to an EVD performed through a new burr hole from 2009 through 2010 at two Depts. of Neurosurgery in Denmark (Odense and Aarhus) were retrospectively identified. Patient files were evaluated for EVD fixation technique (tunneled or bolt-connected EVD) and...... %), compared to the bolt-connected EVD group (6.5 %). There was no significant difference in infection rates. CONCLUSIONS: Tunneled EVD has a relatively high frequency of complications leading to reinsertion. The use of Bolt-connected EVD technique can lower this frequency significantly. The number needed to...

  5. The research of the stud bolt bore checking equipment of the nuclear reactor pressure vessel

    International Nuclear Information System (INIS)

    This article introduces a kind of new equipment that can work under the environment of high radiation and can-automaticly check the main stud bolt bore. The technical parameters and key techniques of the checking equipment are presented. (authors)

  6. On the performance of Usain Bolt in the 100 metre sprint

    CERN Document Server

    Gómez, J J Hernández; Gómez, R W

    2013-01-01

    A theoretical model of the performance of the 100 m world record sprint of Usain Bolt during the 2009 World Championships at Berlin is developed, assuming a drag force proportional to $v$ and to $v^2$. The resulting equation of motion is solved and fitted to the experimental data obtained from the International Amateur of Athletics Federations that recorded Bolt's position with a LAVEG (laser velocity guard) device. It is worth to note that our model works only for short sprints.

  7. Experimental analysis of thread movement in bolted connections due to vibrations

    Science.gov (United States)

    Ramsey, G. ED; Jenkins, Robert C.

    1995-01-01

    This is the final report of research project NAS8-39131 #33 sponsored by NASA's George C. Marshall Space Flight Center (MSFC) and carried out by the Civil Engineering Department of Auburn University (Auburn, Alabama) and personnel of MSFC. The objective of this study was to identify the main design parameters contributing to the loosening of bolts due to vibration and to identify their relative importance and degree of contribution to bolt loosening. Vibration testing was conducted on a shaketable with a controlled-random input in the dynamic testing laboratory of the Structural Test Division of MSFC. Test specimens which contained one test bolt were vibrated for a fixed amount of time and a percentage of pre-load loss was measured. Each specimen tested implemented some combination of eleven design parameters as dictated by the design of experiment methodology employed. The eleven design parameters were: bolt size (diameter), lubrication on bolt, hole tolerance, initial pre-load, nut locking device, grip length, thread pitch, lubrication between mating materials, class of fit, joint configuration, and mass of configuration. These parameters were chosen for this experiment because they are believed to be the design parameters having the greatest impact on bolt loosening. Two values of each design parameter were used and each combination of parameters tested was subjected to two different directions of vibration and two different g-levels of vibration. One replication was made for each test to gain some indication of experimental error and repeatability and to give some degree of statistical credibility to the data, resulting in a total of 96 tests being performed. The results of the investigation indicated that nut locking devices, joint configuration, fastener size, and mass of configuration were significant in bolt loosening due to vibration. The results of this test can be utilized to further research the complex problem of bolt loosening due to vibration.

  8. Asymptotic Analysis of the Load Transfer on Double-Lap Bolted Joints

    OpenAIRE

    KRATOCHVIL, Jan

    2012-01-01

    In this thesis, the complex potential method along with the method of compound asymptotic expansions is applied to the analysis of selected problems of plane elasticity related to double-lap bolted joints. The contribution to the thesis lies in the construction of several closed-form approximations of solutions to the considered problems. After a brief introduction of the basic theoretical concepts in Chapter 2, a mathematical model of a double-lap bolted joint is presented in Chapter 3....

  9. Bolting sequence for attaching the container to the strong-back for 241SY101

    International Nuclear Information System (INIS)

    This bolting sequence is for attaching the container to the strong-back for Tank 241-SY-101. This supporting document includes information for the proper bolting sequence for attaching the container to the strong-back is found in supporting document WHC-SD-WM-DA-165 (WHC 1994a) and is in accordance with Standard Arch-Civil Design Criteria, Design Loads for Facilities (SDC 4.1) Safety Class 3

  10. Magnetic resonance imaging and computer tomography of brain lesions in water buffaloes and cattle stunned with handguns or captive bolts.

    Science.gov (United States)

    Schwenk, Barbara K; Lechner, Isabel; Ross, Steffen G; Gascho, Dominic; Kneubuehl, Beat P; Glardon, Matthieu; Stoffel, Michael H

    2016-03-01

    Owing to the demand for genuine mozzarella, some 330 water buffaloes are being slaughtered every year in Switzerland albeit a stunning procedure meeting animal welfare and occupational safety requirements remains to be established. To provide a basis for improvements, we sized anatomical specifics in water buffaloes and cattle and we assessed brain lesions after stunning with captive bolts or handguns by diagnostic imaging. In water buffaloes and cattle, the median distance from the frontal skin surface to the inner bone table was 74.0mm (56.0-100.0mm) vs 36.6mm (29.3-44.3mm) and from skin to the thalamus 144.8mm (117.1-172.0mm) vs 102.0 (101.0-121.0mm), respectively. Consequently, customary captive bolt stunners may be inadequate. Free bullets are potentially suitable for stunning buffaloes but involve occupational safety hazards. The results of the present study shall be used to develop a device allowing effective and safe stunning of water buffaloes. PMID:26610289

  11. A new approach for field instrumentation in grouted rock bolt monitoring using guided ultrasonic waves

    Science.gov (United States)

    Zou, D. H.; Cui, Y.

    2011-11-01

    A rock bolt installed in the field for ground support has only one short exposed end on the rock surface. This condition has posed challenges in field instrumentation. In this paper, a new approach for field monitoring of grouted rock bolts using guided ultrasonic waves is proposed with the receiving transducer on the grout surface near the exposed end of the bolt. The effects of the receiver location are studied with numerical modeling. A location correction factor is introduced to correlate the amplitude ratio along the bolt and that on the grout surface. Experiments are conducted to verify the modeling results. This research indicates that it is practically possible to receive meaningful signals with the receiver on the grout surface and that with the recorded data the attenuation and wave velocity of guided waves in grouted rock bolts can be determined with reasonable accuracy. The proper receiver location is found to be 27 to 32 mm from the bolt center for the test condition.

  12. Ultimate strength of single shear bolted connections with cold-formed ferritic stainless steel

    Institute of Scientific and Technical Information of China (English)

    Jin-seong LIM; Tae-soo KIM; Seung-hun KIM

    2013-01-01

    This paper is focused on the structural behavior of the single shear bolted connections with thin-walled ferritic stainless steel.The purpose of this study is to investigate the ultimate behaviors,such as ultimate strength and fracture mode of the single shear bolted connections of thin-walled ferritic stainless steel (low cost steel) rather than austenitic stainless steel (high cost steel).Bolt arrangement and end distance parallel to the direction of applied load are considered as main variables of the test specimens for bolted connections.Specimens have a constant dimension of edge distance perpendicular to the loading direction,bolt diameter,pitch,and gauge.A monotonic tensile test for specimens has been carried out and some bolted connections with long end distance showed curling (out of plane deformation) occurrence which led to strength reduction.The ultimate behaviors such as fracture mode,ultimate strength are compared with those predicted by current design codes.Further,conditions of curling occurrence and the strength reduction due to curling are investigated and modified strength equations are suggested considering the curling effect.

  13. Nonlinear Bending Stiffness of Plates Clamped by Bolted Joints under Bending Moment

    Science.gov (United States)

    Naruse, Tomohiro; Shibutani, Yoji

    Equivalent stiffness of plates clamped by bolted joints for designing should be evaluated according to not only the strength of bolted joints but also the deformation and vibration characteristics of the structures. When the applied external axial load or the bending moment is sufficiently small, the contact surfaces of the bolted joint are stuck together, and thus both the bolt and the clamped plates deform linearly. Although the sophisticated VDI 2230 code gives the appropriate stiffness of clamped plates for the infinitesimal deformation, the stiffness may vary nonlinearly with increasing the loading because of changing the contact state. Therefore, the present paper focuses on the nonlinear behaviour of the bending stiffness of clamped plates by using Finite Element (FE) analyses, taking the contact condition on bearing surfaces and between the plates into account. The FE models of the plates with thicknesses of 3.2, 4.5, 6.0 and 9.0 mm tightened with M8, 10, 12 and 16 bolts were constructed. The relation between bending moment and bending compliance of clamped plates is found to be categorized into three regions, namely, (i) constant compliance with fully stuck contact surfaces, (ii) transition showing the nonlinear compliance, and (iii) constant compliance with one-side contact surfaces. The mechanical models for these three regions are proposed and compared with FEM solutions. The prediction on the bounds of three regions is in a fairly good agreement except the case with smaller bolts and thicker plates.

  14. Requirements for energy based constitutive modeling in tire mechanics

    Science.gov (United States)

    Luchini, John R.; Peters, Jim M.; Mars, Will V.

    1995-01-01

    The history, requirements, and theoretical basis of a new energy based constitutive model for (rubber) material elasticity, hysteresis, and failure are presented. Energy based elasticity is handled by many constitutive models, both in one dimension and in three dimensions. Conversion of mechanical energy to heat can be modeled with viscoelasticity or as structural hysteresis. We are seeking unification of elasticity, hysteresis, and failure mechanisms such as fatigue and wear. An energy state characterization for failure criteria of (rubber) materials may provide this unification and also help explain the interaction of temperature effects with failure mechanisms which are described as creation of growth of internal crack surface. Improved structural modeling of tires with FEM should result from such a unified constitutive theory. The theory will also guide experimental work and should enable better interpretation of the results of computational stress analyses.

  15. Requirements for energy based constitutive modeling in tire mechanics

    Science.gov (United States)

    Luchini, John R.; Peters, Jim M.; Mars, Will V.

    1995-08-01

    The history, requirements, and theoretical basis of a new energy based constitutive model for (rubber) material elasticity, hysteresis, and failure are presented. Energy based elasticity is handled by many constitutive models, both in one dimension and in three dimensions. Conversion of mechanical energy to heat can be modeled with viscoelasticity or as structural hysteresis. We are seeking unification of elasticity, hysteresis, and failure mechanisms such as fatigue and wear. An energy state characterization for failure criteria of (rubber) materials may provide this unification and also help explain the interaction of temperature effects with failure mechanisms which are described as creation of growth of internal crack surface. Improved structural modeling of tires with FEM should result from such a unified constitutive theory. The theory will also guide experimental work and should enable better interpretation of the results of computational stress analyses.

  16. Modelling requirements for future assessments based on FEP analysis

    International Nuclear Information System (INIS)

    This report forms part of a suite of documents describing the Nirex model development programme. The programme is designed to provide a clear audit trail from the identification of significant features, events and processes (FEPs) to the models and modelling processes employed within a detailed safety assessment. A scenario approach to performance assessment has been adopted. It is proposed that potential evolutions of a deep geological radioactive waste repository can be represented by a base scenario and a number of variant scenarios. The base scenario is chosen to be broad-ranging and to represent the natural evolution of the repository system and its surrounding environment. The base scenario is defined to include all those FEPs that are certain to occur and those which are judged likely to occur for a significant period of the assessment timescale. The structuring of FEPs on a Master Directed Diagram (MDD) provides a systematic framework for identifying those FEPs that form part of the natural evolution of the system and those, which may define alternative potential evolutions of the repository system. In order to construct a description of the base scenario, FEPs have been grouped into a series of conceptual models. Conceptual models are groups of FEPs, identified from the MDD, representing a specific component or process within the disposal system. It has been found appropriate to define conceptual models in terms of the three main components of the disposal system: the repository engineered system, the surrounding geosphere and the biosphere. For each of these components, conceptual models provide a description of the relevant subsystem in terms of its initial characteristics, subsequent evolution and the processes affecting radionuclide transport for the groundwater and gas pathways. The aim of this document is to present the methodology that has been developed for deriving modelling requirements and to illustrate the application of the methodology by

  17. Lubrication properties of silver-palladium alloy prepared by ion plating method for high temperature stud bolt

    Institute of Scientific and Technical Information of China (English)

    Jung-Dae KWON; Sunghun LEE; Koo-Hyun LEE; Jong-Joo RHA; Kee-Seok NAN; Se-Hun KWON

    2011-01-01

    As a solid lubricant, silver-palladium (Ag-Pd) alloy coating was investigated for the application to high temperature studbolt. A glue layer nickel (Ni) film was deposited on the surface of the hex bolt sample and then Ag-Pd alloy coating was performed on it using ion plating method. The friction coefficient of Ag-Pd alloy film coated bolt was lower than that of N-5000 oil coated bolt by the result of axial force measurement. The cyclic test of heat treatment was conducted to evaluate the durability of Ag-Pd alloy film coated bolt. In a cycle, sample was assembled into the block using torque wrench, followed by heating and disassembling. It was not successful to disassemble the N-5000 oil coated bolt from the block after only one cycle. However, the Ag-Pd alloy film coated bolt was able to be disassembled softly till 12 cycles.

  18. Assessing the effects of insufficient rebar and missing grout in grouted rock bolts using guided ultrasonic waves

    Science.gov (United States)

    Cui, Y.; Zou, D. H.

    2012-04-01

    One of the challenges in field monitoring of grouted rock bolts, which normally have a short exposed end, is to detect the defects of the bolt or grout. In this paper, grouted rock bolts are studied using guided ultrasonic waves. Numerical modeling for grouted rock bolts is performed to assess the effects of insufficient rebar and missing grout. The numerical results are verified with laboratory tests on rock bolt samples. With introduction of correction factors at the reflection end, the results indicate that it is practically possible to identify insufficient rebar and grout defects with guided ultrasonic signals received at the exposed end. It also indicates that with the attenuation and wave velocity of guided waves, defective rock bolts with insufficient rebar length or missing grout in the ground can be detected with reasonable accuracy.

  19. On the applicability of high strength self-tapping aluminium bolts in magnesium nut materials for automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Gerstmayr, G.; Leitner, H.; Eichlseder, W. [Mechanical Engineering, University of Leoben (Austria); Mori, G. [CD-Laboratory of Localized Corrosion - General, Analytical and Physical Chemistry, University of Leoben (Austria)

    2010-05-15

    High strength aluminium bolts made of AW 6056 T6, AW 7075 T6 and T79 have been investigated regarding the applicability in magnesium nut materials for automotive applications. With respect to galvanic corrosion all combinations of aluminium bolts with magnesium parts show superior corrosion properties when compared to galvanised steel bolts connected to magnesium. With respect to stress corrosion cracking (SCC) no aluminium bolt in contact with magnesium failed due to SCC. This is because of cathodic protection of aluminium alloy through magnesium. Even peak-tempered highest strengthened T6 7xxx aluminium bolts can be used for automotive applications when compressive residual stresses are present in the thread root of the bolts. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  20. Improving boiler foundation bolt installation technology%提高锅炉地脚螺栓安装工艺

    Institute of Scientific and Technical Information of China (English)

    李晓峰

    2014-01-01

    阐述了锅炉地脚螺栓安装前的准备工作,通过对螺栓安装施工工艺流程的介绍,分析了提高螺栓与螺栓支架安装精度的方法,并对检验螺栓安装质量的技术要点作了研究,以确保锅炉地脚螺栓安装的正确无误。%The paper illustrates boiler foundation bolt installation preparations. Through introducing bolt installation technology procedures, it analyzes methods of improving bolt and bolt support installation accuracy, and studies technological points of examining bolt installation quality, with a view to guarantee boiler foundation bolt installation correct.

  1. European development Rock bolting; Desarrollo Europeo del Bulonaje

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    The project European Development Rockbolting which was developed during the period 1994-1997 and carried out within the OCICARBON Action Program (OCICARBON-ITGE agreement dated September 1, 1994, Code C-13-438) as well as within the framework of the Coal Technical research Program of the D. G. XVII of the EEC, n 7220/AB/143. The project has had the following external partners: DMT (Germany), BCC (UK) and CDF (France), and the collaboration of INERIS (France), RMT (UK) and GEOCONTROL S. A. (Spain). The objective of the investigation was to improve the techniques and design currently used in the application of rockbolts for supporting of both infrastructure and beds in the European coal mining. The most important result, besides that derived from the sharing of experiences and knowledge, was the technological design of a supporting system, which was carried out by each partner for the various proposed exploitations. The Spanish part carried out the works of designing and estimation of the bolting system corresponding to the exploitations of: -Carbones de Pedraforca SA. Saldes mine. -U. E. Provence. Pit Y. Morandat.

  2. Forces in bolted joints: analysis methods and test results utilized for nuclear core applications (LWBR Development Program)

    International Nuclear Information System (INIS)

    Analytical methods and test data employed in the core design of bolted joints for the LWBR core are presented. The effects of external working loads, thermal expansion, and material stress relaxation are considered in the formulation developed to analyze joint performance. Extensions of these methods are also provided for bolted joints having both axial and bending flexibilities, and for the effect of plastic deformation on internal forces developed in a bolted joint. Design applications are illustrated by examples

  3. Cortisol Hormone Concentration and Meat Quality of Beef Cattle Stunned by Captive Bolt Stun Gun before Slaughtering

    Directory of Open Access Journals (Sweden)

    K. Maghfiroh

    2014-12-01

    Full Text Available This study was aimed to describe cortisol hormone concentration and meat quality which were produced in beef cattle stunned with captive bolt stun gun before slaughtering. Blood and meat samples were taken from Brahman cross steers (n= 11 in two abattoirs located in West Java and Banten. Blood samples were collected immediately after slaughtering. Cortisol hormone concentration in the serum was measured by using radioimmunoassay (RIA. The descriptive, correlation, and regression analyses were used to interprete data. Meat quality assessment was based on pH, cooking loss, and complete drainage of blood. The average of cortisol hormone concentration was 26.59 ng/mL. Meat pH at 1 h postmortem and 24 h postmortem were 6.65 and 6.21, respectively. Meat cooking loss was 26.77%. Blood drainage in meat samples of each cattle showed complete drainage. There was a significant correlation (P<0.05 between cortisol concentrations and pH at 1 hour postmortem as well as cortisol concentration and cooking loss. There was no significant correlation between pH at 24 h postmortem and cooking loss. Cattle was stunned with a captive bolt stun gun before slaughtering produced meat with complete blood drainage but had high cortisol hormone concentration and pH ultimate.

  4. A closed-loop based framework for design requirement management

    DEFF Research Database (Denmark)

    Zhang, Zhinan; Li, Xuemeng; Liu, Zelin

    2014-01-01

    Requirement management plays a crucial role in determining a successful engineering design project. The focus of current requirement research is on the development of requirement elicitation, analysis and formalization methods and tools. Moreover, the existing requirement research often pays...... attention to the fuzzy front end of product design process. In fact, there exists more needs for requirement knowledge at each stage of a product lifecycle and requirement also has its own lifecycle. However, the research in the field of engineering design lack of a framework to support requirement...... management from product lifecycle, and requirement and requirement management lifecycle views. This paper highlights the importance of requirement lifecycle management and aims at closing the requirement information loop in product lifecycle. Then, it addresses the requirement management in engineering...

  5. A closed-loop based framework for design requirement management

    OpenAIRE

    Zhang, Zhinan; Li, Xuemeng; Liu, Zelin

    2014-01-01

    Requirement management plays a crucial role in determining a successful engineering design project. The focus of current requirement research is on the development of requirement elicitation, analysis and formalization methods and tools. Moreover, the existing requirement research often pays attention to the fuzzy front end of product design process. In fact, there exists more needs for requirement knowledge at each stage of a product lifecycle and requirement also has its own lifecycle. Howe...

  6. Space station data system analysis/architecture study. Task 1: Functional requirements definition, DR-5. Appendix: Requirements data base

    Science.gov (United States)

    1985-01-01

    Appendix A contains data that characterize the system functions in sufficient depth as to determine the requirements for the Space Station Data System (SSDS). This data is in the form of: (1) top down traceability report; (2) bottom up traceability report; (3) requirements data sheets; and (4) cross index of requirements paragraphs of the source documents and the requirements numbers. A data base users guide is included that interested parties can use to access the requirements data base and get up to date information about the functions.

  7. Modeling and Composing Scenario-Based Requirements with Aspects

    Science.gov (United States)

    Araujo, Joao; Whittle, Jon; Ki, Dae-Kyoo

    2004-01-01

    There has been significant recent interest, within the Aspect-Oriented Software Development (AOSD) community, in representing crosscutting concerns at various stages of the software lifecycle. However, most of these efforts have concentrated on the design and implementation phases. We focus in this paper on representing aspects during use case modeling. In particular, we focus on scenario-based requirements and show how to compose aspectual and non-aspectual scenarios so that they can be simulated as a whole. Non-aspectual scenarios are modeled as UML sequence diagram. Aspectual scenarios are modeled as Interaction Pattern Specifications (IPS). In order to simulate them, the scenarios are transformed into a set of executable state machines using an existing state machine synthesis algorithm. Previous work composed aspectual and non-aspectual scenarios at the sequence diagram level. In this paper, the composition is done at the state machine level.

  8. [Calculating method for crop water requirement based on air temperature].

    Science.gov (United States)

    Tao, Guo-Tong; Wang, Jing-Lei; Nan, Ji-Qin; Gao, Yang; Chen, Zhi-Fang; Song, Ni

    2014-07-01

    The importance of accurately estimating crop water requirement for irrigation forecast and agricultural water management has been widely recognized. Although it has been broadly adopted to determine crop evapotranspiration (ETc) via meteorological data and crop coefficient, most of the data in whether forecast are qualitative rather than quantitative except air temperature. Therefore, in this study, how to estimate ETc precisely only using air temperature data in forecast was explored, the accuracy of estimation based on different time scales was also investigated, which was believed to be beneficial to local irrigation forecast as well as optimal management of water and soil resources. Three parameters of Hargreaves equation and two parameters of McClound equation were corrected by using meteorological data of Xinxiang from 1970 to 2010, and Hargreaves equation was selected to calculate reference evapotranspiration (ET0) during the growth period of winter wheat. A model of calculating crop water requirement was developed to predict ETc at time scales of 1, 3, and 7 d intervals through combining Hargreaves equation and crop coefficient model based on air temperature. Results showed that the correlation coefficients between measured and predicted values of ETc reached 0.883 (1 d), 0.933 (3 d), and 0.959 (7 d), respectively. The consistency indexes were 0.94, 0.95 and 0.97, respectively, which showed that forecast error decreased with the increasing time scales. Forecasted accuracy with an error less than 1 mm x d(-1) was more than 80%, and that less than 2 mm x d(-1) was greater than 90%. This study provided sound basis for irrigation forecast and agricultural management in irrigated areas since the forecasted accuracy at each time scale was relatively high. PMID:25345053

  9. International Space Station Powered Bolt Nut Anomaly and Failure Analysis Summary

    Science.gov (United States)

    Sievers, Daniel E.; Warden, Harry K.

    2010-01-01

    A key mechanism used in the on-orbit assembly of the International Space Station (ISS) pressurized elements is the Common Berthing Mechanism. The mechanism that effects the structural connection of the Common Berthing Mechanism halves is the Powered Bolt Assembly. There are sixteen Powered Bolt Assemblies per Common Berthing Mechanism. The Common Berthing Mechanism has a bolt which engages a self aligning Powered Bolt Nut (PBN) on the mating interface (Figure 1). The Powered Bolt Assemblies are preloaded to approximately 84.5 kN (19000 lb) prior to pressurization of the CBM. The PBNs mentioned below, manufactured in 2009, will be used on ISS future missions. An on orbit functional failure of this hardware would be unacceptable and in some instances catastrophic due to the failure of modules to mate and seal the atmosphere, risking loss of crew and ISS functions. The manufacturing processes that create the PBNs need to be strictly controlled. Functional (torque vs. tension) acceptance test failures will be the result of processes not being strictly followed. Without the proper knowledge of thread tolerances, fabrication techniques, and dry film lubricant application processes, PBNs will be, and have been manufactured improperly. The knowledge gained from acceptance test failures and the resolution of those failures, thread fabrication techniques and thread dry film lubrication processes can be applied to many aerospace mechanisms to enhance their performance. Test data and manufactured PBN thread geometry will be discussed for both failed and successfully accepted PBNs.

  10. Effect of Fully Grouted Passive Bolts on Joint Shear Strength Parameters in a Blocky Mass

    Science.gov (United States)

    Srivastava, Lok Priya; Singh, Mahendra

    2015-05-01

    The present paper discusses an experimental study on shear strength response of unreinforced and reinforced block masses to find out the effect of fully grouted passive bolts on the shear strength parameters of joints in a mass. Direct shear tests were conducted on specimens of large-sized blocky masses, each with a dimension of 750 × 750 × 900 mm. Each blocky mass was assembled by piling elemental blocks of size 150 × 150 × 150 mm. For the reinforced condition, the mass was reinforced with three, five, and nine bolts perpendicular to the shear plane. The tests were conducted at different normal stress levels ranging from 0 to 2 MPa, which are common in rock slopes. Results from the tests show that passive bolts enhance the joint shear strength parameters. The strength enhancement is mainly due to improved interlocking and therefore, enhanced cohesion. The value of enhanced cohesion depends on the bolt area, the ratio of bolt spacing to block size and the strength of the intact material for a given set of steel and grout. A correlation has been established to find out enhanced cohesion for the given joints in the mass.

  11. Grout quality and its impact on guided ultrasonic waves in grouted rock bolts

    Science.gov (United States)

    Zou, D. H. Steve; Cheng, Jiulong; Yue, Renjie; Sun, Xiaoyun

    2010-10-01

    Rock bolts are widely used in mining and geotechnical engineering as ground anchorage. The supporting capacity of grouted rock bolts depends greatly on the grout quality in rocks. Measurement of the grout quality in the field is an outstanding issue. In an effort to develop a non-destructive method for estimating the grout quality of grouted rock bolts, the characteristics of guided ultrasonic waves are investigated in this paper. Particular attention is paid to the effects of grout quality on group wave velocity and attenuation. Issues associated to grout quality and bolt failure are also discussed. To simulate the in-situ condition, several specimens were prepared using 20 mm diameter rebar. Each specimen was grouted in a 200 mm diameter concrete cylinder, which was designed with different compressive strength. A large number of tests were conducted on these specimens using ultrasonic waves with frequencies from 10 to 100 kHz. The effects of air content and compressive strength of the grout on attenuation and group velocity of ultrasonic waves in the grouted rock bolts were studied. The results showed large influence from the grout strength and air content and demonstrated the potential for using ultrasonic waves to test grout quality.

  12. Parameter analysis of anchor bolt support for large-span and jointed rock mass

    Institute of Scientific and Technical Information of China (English)

    LI Xi-bing; ZHOU Zi-long; LI Qi-yue; HU Liu-qing

    2005-01-01

    In order to obtain the optimal parameters of anchor bolt supporting system for large-span and jointed rock mass in Kaiyang Phosphor Mine, it is expensive and unavailable with the method of in-situ experiments. This paper describes a numerical modeling with discrete element method for the supporting effects of different type of anchor bolts. The anchor bolts with variant length of 0.5 m, 0.8 m, 1.0 m, diameter of 10 mm, 15 mm, 20 mm, setting spacing of 3.0 m, 2.5 m, 2.0 m, and setting angle of 10°, 20°, 30°, are simulated respectively. The results show that there exist optimal parameters of anchor bolt support for large-span and jointed rock mass. For the bolt support of the concerning, the optimal length is 2.5-3.5 m, the diameter is 25-35 mm, the spacing is 0.5-0.6 m, and the setting angle is 105°.

  13. Proteomic and gene expression analyses during bolting-related leaf color change in Brassica rapa.

    Science.gov (United States)

    Zhang, Y W; Guo, M H; Tang, X B; Jin, D; Fang, Z Y

    2016-01-01

    Bolting and flowering are key processes during the growth and development of Chinese cabbage (Brassica rapa L. ssp pekinensis). Understanding the molecular mechanisms underlying bolting and flowering is of significance for improving production of the vegetable. A leaf-color change from bright green to gray-green has been observed following differentiation of the flowering stem and before bolting in the vegetable, and is considered to be a signal for bolting. Proteomics in meristem tissues of an inbred line (C30) were analyzed by two-dimensional electrophoresis during the transition period. We found that some proteins were specifically expressed while others were differentially expressed. Among these, 17 proteins were specifically expressed before the color change, 18 were specifically expressed after the color change, 21 were downregulated during the color change, and 29 were upregulated. Mass spectrometric analysis (MALDI-TOF-TOF/MS) was used to analyze 17 protein spots, and four proteins (subunit E1 of vacuolar-type H+ transporter ATPase, the large subunit of Rubicon, S-adenosylmethionine synthetase, and tubulin α-2) were identified. qPCR analysis was conducted to quantify the expression of genes encoding these proteins during the transitional period. The expression of BrVHA-E1, BrSAMS, BrrbcL, and BrTUA6 was significantly different before and after the leaf-color change, suggesting that these genes might be involved in regulating flower differentiation and bolting. PMID:27525926

  14. Submillimeter bolt location in car bodywork for production line quality inspection

    Science.gov (United States)

    Altamirano-Robles, Leopoldo; Arias-Estrada, Miguel; Alviso-Quibrera, Samuel; Lopez-Lopez, Aurelio

    2000-03-01

    In the automotive industry, a vehicle begins with the construction of the vehicle floor. Later on, several robots weld a series of bolts to this floor which are used to fix other parts. Due to several problems, like welding tools wearing, robot miscalibration or momentary low power supply, among others, some bolts are incorrectly positioned or are not present at all, bringing problems and delays in the next work cells. Therefore, it is of importance to verify the quality of welded parts before the following assembly steps. A computer vision system is proposed in order to locate autonomously the presence and quality of the bolts. The system should carry on the inspection in real time at the car assembly line under the following conditions: without touching the bodywork, with a precision in the submillimeter range and in few seconds. In this paper we present a basic computer vision system for bolt location in the submillimeter range. We analyze three arrangements of the system components (camera and illumination sources) that produce different results in the localization. Results are presented and compared for the three approaches obtained under laboratory conditions. The algorithms were tested in the assembling line. Variations up to one millimeter in the welded position of the bolts were observed.

  15. A User Requirements Analysis Approach Based on Business Processes

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yue-bin; HAN Wen-xiu

    2001-01-01

    Requirements analysis is the most important phase of information system development.Existing requirements analysis techniques concern little or no about features of different business processes.This paper presents a user requirements analysis approach which focuses business processes on the early stage of requirements analysis. It also gives an example of the using of this approach in the analysis of an enterprise information system.

  16. Argumentation-based security requirements elicitation: the next round

    NARCIS (Netherlands)

    Ionita, Dan; Bullee, Jan-Willem; Wieringa, Roel

    2014-01-01

    Information Security Risk Assessment can be viewed as part of requirements engineering because it is used to translate security goals into security requirements, where security requirements are the desired system properties that mitigate threats to security goals. To improve the defensibility of the

  17. Assessment of Performance-based Requirements for Structural Design

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2005-01-01

    and for a detailed assessment of the requirements. The design requirements to be used for a factory producing elements for industrial housing for unknown costumers are discussed, and a fully developed fire is recommended as a common requirement for domestic houses, hotels, offices, schools and...

  18. A History-based Estimation for LHCb job requirements

    Science.gov (United States)

    Rauschmayr, Nathalie

    2015-12-01

    The main goal of a Workload Management System (WMS) is to find and allocate resources for the given tasks. The more and better job information the WMS receives, the easier will be to accomplish its task, which directly translates into higher utilization of resources. Traditionally, the information associated with each job, like expected runtime, is defined beforehand by the Production Manager in best case and fixed arbitrary values by default. In the case of LHCb's Workload Management System no mechanisms are provided which automate the estimation of job requirements. As a result, much more CPU time is normally requested than actually needed. Particularly, in the context of multicore jobs this presents a major problem, since single- and multicore jobs shall share the same resources. Consequently, grid sites need to rely on estimations given by the VOs in order to not decrease the utilization of their worker nodes when making multicore job slots available. The main reason for going to multicore jobs is the reduction of the overall memory footprint. Therefore, it also needs to be studied how memory consumption of jobs can be estimated. A detailed workload analysis of past LHCb jobs is presented. It includes a study of job features and their correlation with runtime and memory consumption. Following the features, a supervised learning algorithm is developed based on a history based prediction. The aim is to learn over time how jobs’ runtime and memory evolve influenced due to changes in experiment conditions and software versions. It will be shown that estimation can be notably improved if experiment conditions are taken into account.

  19. Ultraprecision XY stage using a hybrid bolt-clamped Langevin-type ultrasonic linear motor for continuous motion

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong-Jin; Lee, Sun-Kyu, E-mail: skyee@gist.ac.kr [School of Mechatronics, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2015-01-15

    This paper presents a design and control system for an XY stage driven by an ultrasonic linear motor. In this study, a hybrid bolt-clamped Langevin-type ultrasonic linear motor was manufactured and then operated at the resonance frequency of the third longitudinal and the sixth lateral modes. These two modes were matched through the preload adjustment and precisely tuned by the frequency matching method based on the impedance matching method with consideration of the different moving weights. The XY stage was evaluated in terms of position and circular motion. To achieve both fine and stable motion, the controller consisted of a nominal characteristics trajectory following (NCTF) control for continuous motion, dead zone compensation, and a switching controller based on the different NCTFs for the macro- and micro-dynamics regimes. The experimental results showed that the developed stage enables positioning and continuous motion with nanometer-level accuracy.

  20. 应力波干涉配合螺接%Stress wave intervening concerted bolt connection

    Institute of Scientific and Technical Information of China (English)

    杨亚文; 李淑萍; 段宝

    2001-01-01

    This paper introduces the importance of fatigue life to the quality of products and the effect of intervening parametre on fatigue life. The method is also proposed on making thread-hole and bolt in interving concerted process, bolt connection as well. In the meantime a new connection method called stress wave bolt connection is introduced.%主要介绍了疲劳寿命对产品质量的重要性,干涉量对疲劳寿命的影响。干涉配合螺接过程中螺孔和螺栓的加工方法以及螺栓的安装方法。另外,还介绍了一种新的干涉配合螺接方法——应力波螺接。

  1. An analysis of bolt strength carrier rail foundation of gamma irradiator for sterilization of agricultural products

    International Nuclear Information System (INIS)

    It has been designed foundation bolts to fasten the rail carrier at closed loop circuit in the sterilization and non sterilization room, in which the circuit length is about 100 meter. The rail will be used as a circuit by 19 carriers in which each carrier has weight about 19000 kg. The 19000 kg load will be in motion or stand still, hung up for 24 working hours, and produce same vibrations. Therefore an analysis for the strength of the bolt foundation should be carried out for the sake of safety of related instruments, agricultural products, and the operator in duty. From the calculation shows that the bolt of M16x2 with effective length 455 mm can be used, and the vibration can be attenuated using style -31.4847 kg of force, so that the vibration will stop at the time the carrier moving. (author)

  2. Process and device for the handling of large size gudgeon bolts

    International Nuclear Information System (INIS)

    This invention concerns the handling of large size long pieces and particularly gudgeon bolts employed for securing the closures of nuclear reactor vessels. This device enables the gudgeon to be moved vertically and pivoted into a horizontal position and vice versa. It includes a pivoting arm that can tilt about a fixed axis and used to guide a mobile trolley that can move along this arm and fitted with supports for the lower part of the gudgeon bolt. At least one cable includes one end fixed to the mobile trolley, the other end cooperating with a fixed winch. The preferably single cable passes over a loose pulley integral with the arm. In this manner, by actuating the winch and simply acting on this cable, it is possible to obtain the vertical displacement of the gudgeon bolt and its pivoting into the horizontal position and vice versa at one and the same time

  3. Stress corrosion cracking of HP turbine using bolts of 900 MW CP1 units

    International Nuclear Information System (INIS)

    Failures or cracks of HP turbine casing bolts of the 900 MW PWR units are due to stress corrosion in humid steam and in presence of chlorinated solvents used during maintenance operations or before the mounting of bolts. This phenomenon does not concern only the steel used (35 NCD6 or 28 CDV 5-08), for the phenomenon has been reproduced in laboratory on other steel qualities, more particularly the Z 12 CNDV 12-2 steel. This steel would present a better resistance to this type of corrosion at temperatures lower than 2500C. Action have been undertaken to avoid these problems: systematic control at each casing opening; cleaning of bolts and bores for turbines having presented the phenomenon; chlorinated products are prohibited; change of the joint which ensures tightness, utilization of the Z 12 CNDV 12-2 steel quality and, study of the increase of screwing to keep the joint tight

  4. Numerical Computation of Stress Intensity Factors for Bolt-hole Corner Crack in Mechanical Joints

    Institute of Scientific and Technical Information of China (English)

    Wang Liqing; Gai Bingzheng

    2008-01-01

    The three-dimensional finite element method is used to solve the problem of the quarter-elliptical comer crack of the bolt-hole in mechanical joints being subjected to remote tension. The square-root stress singularity around the corner crack front is simulated using the collapsed 20-node quarter point singular elements. The contact interaction between the bolt and the hole boundary is considered in the finite element analysis. The stress intensity factors (SIFs) along the crack front are evaluated by using the displacement correlation technique. The effects of the amount of clearance between the hole and the bolt on the SIFs are investigated. The numerical results indicate that the SIF for mode I decrease with the decreases in clearance, and in the cases of clearance being present, the corner crack is in a mix-mode, even if mode I loading is dominant.

  5. Investigation of corrosion and stress corrosion cracking in bolting materials on light water reactors

    International Nuclear Information System (INIS)

    Laboratory experiments performed at BNL have shown that the concentration of boric acid to a moist paste at approximately the boiling point of water can produce corrosion rates of the order of several tenths of an inch per year on bolting and piping materials, which values are consistent with service experience. Other failure evaluation experience has shown that primary coolant/lubricant interaction may lead to stress corrosion cracking (SCC) of steam generator manway studs. An investigation was also performed on eleven lubricants and their effects on A193 B7 and A540 B24 bolting materials. H2S generation by the lubricants, coefficient of friction results and transgranular SCC of the bolting materials in steam are discussed. 13 refs

  6. Software Requirement Analysis Enhancements by Prioritizing Requirement Attributes Using Rank Based Agents

    OpenAIRE

    Ashok Kumar; Vinay Goyal

    2011-01-01

    This paper proposes a new technique in the domain of Agent oriented software engineering. Agents work in autonomous environments and can respond to agent triggers. Agents can be very useful in requirement analysis phase of software development process, where they can react towards the requirement triggers and result in aligned notations to identify the best possible design solution from existing designs. Agent helps in design generation process, which includes the use of Artificial intelligen...

  7. Ultrasonic Inspection of Cracks in Stud Bolts of Reactor Vessels in Nuclear Power Plants by Signal Processing of Differential Operation

    International Nuclear Information System (INIS)

    The stud bolt is one of crucial parts for safe operation of reactor vessels in nuclear power plants, Crack initiation and propagation were reported in stud bolts that arc used for closure of reactor vessel and head, Stud bolts are inspected by ultrasonic technique during overhaul periodically for the prevention of stud bolt failure which could induce radioactive leakage from nuclear reactor, In conventional ultrasonic testing for inspection of stud bolts, cracks are detected by using shadow effect It takes too much time to inspect stud bolts by using conventional ultrasonic technique. In addition, there were numerous spurious signals reflected from every oblique surfaces of thread, In this study, the signal processing technique for enhancing conventional ultrasonic technique was introduced for inspecting stud bolts. The signal processing technique provides removing spurious signal reflected from every oblique surfaces of thread and enhances detectability of defects. Detectability for small crack was enhanced by using this signal processing in ultrasonic inspection of stud bolts in Nuclear Power Plants

  8. Ultrasonic Inspection of Cracks in Stud Bolts of Reactor Vessels in Nuclear Power Plants by Signal Processing of Differential Operation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sang Woo [Northwestern University, Evanston (United States); Lee, Joon Hyun; Oh, Won Deok [Pusan National University, Busan (Korea, Republic of)

    2005-12-15

    The stud bolt is one of crucial parts for safe operation of reactor vessels in nuclear power plants, Crack initiation and propagation were reported in stud bolts that arc used for closure of reactor vessel and head, Stud bolts are inspected by ultrasonic technique during overhaul periodically for the prevention of stud bolt failure which could induce radioactive leakage from nuclear reactor, In conventional ultrasonic testing for inspection of stud bolts, cracks are detected by using shadow effect It takes too much time to inspect stud bolts by using conventional ultrasonic technique. In addition, there were numerous spurious signals reflected from every oblique surfaces of thread, In this study, the signal processing technique for enhancing conventional ultrasonic technique was introduced for inspecting stud bolts. The signal processing technique provides removing spurious signal reflected from every oblique surfaces of thread and enhances detectability of defects. Detectability for small crack was enhanced by using this signal processing in ultrasonic inspection of stud bolts in Nuclear Power Plants

  9. An Approach for Performance Based Glove Mobility Requirements

    Science.gov (United States)

    Aitchison, Lindsay; Benson, Elizabeth; England, Scott

    2016-01-01

    occupational therapy arenas to develop a protocol that assesses gloved range of motion, strength, dexterity, tactility, and fit in comparative quantitative terms and also provides qualitative insight to direct hardware design iterations. The protocol was evaluated using five experienced test subjects wearing the EMU pressurized to 4.3psid with three different glove configurations. The results of the testing are presented to illustrate where the protocol is and is not valid for benchmark comparisons. The process for requirements development based upon the results is also presented along with suggested performance values for the High Performance EVA Gloves currently in development.

  10. Experimental Study on a New Bolt Connection Used in Multistory Fabricated Steel Structure%多层预拼装钢结构系统特殊连接螺栓性能试验研究

    Institute of Scientific and Technical Information of China (English)

    丁娟; 张其林; 张齐; 陈国栋; 杨彬

    2014-01-01

    A new kind of bolt connection consisted of self-tapping steel plate and high strength bolt will be used in a multistory fabricated steel structure system.But there are no regulations on such kind of bolted con-nection.Therefore,extensive experimental research on bolted connection was taken.The objective of the re-search was to determine the ductility and resistance of such connection.Different failure modes of bolted con-nections could be observed in the test.The ultimate bearing capacity was compared with that predicted by the current connection provisions specified in Chinese steel design standards.Besides a pretension experience was put,which demonstrates that this new kind of connection can satisfy the requirement of Chinese steel design code on pretension.%某新型多层预拼装钢结构系统采用了钢板自攻螺纹螺栓连接形式,非现行规范中的连接类型,需完成相关试验进行论证。针对工程常用6种规格高强螺栓自攻螺纹连接进行了单向拉伸试验,研究了两种破坏模式,并将极限承载力与规范要求承载力设计值与预紧力进行比对,并且对 M20(8.8S)螺栓进行预紧力时变效应测试,研究表明,此种连接类型在使用过程中可以保持一定的预紧力水平。

  11. A Modified Desirability-Based Prioritization Technique For Software Requirements

    Directory of Open Access Journals (Sweden)

    Carlos E. Otero

    2012-03-01

    Full Text Available This paper presents a methodology for requirement prioritization. The approach provides a flexible and realistic approach that considers all attributes of particular requirements and fuses them into a unified metric, representative of all quality criteria identified for a specific software project. The derived quality measurement can be used as the main metric for requirements prioritization. The methodology addresses flaws from previous work and provides mechanisms for improving its suitability for practical applications.

  12. Towards a Formalized Ontology-Based Requirements Model

    Institute of Scientific and Technical Information of China (English)

    JIANG Dan-dong; ZHANG Shen-sheng; WANG Ying-lin

    2005-01-01

    The goal of this paper is to take a further step towards an ontological approach for representing requirements information. The motivation for ontologies was discussed. The definitions of ontology and requirements ontology were given. Then, it presented a collection of informal terms, including four subject areas. It also discussed the formalization process of ontology. The underlying meta-ontology was determined, and the formalized requirements ontology was analyzed. This formal ontology is built to serve as a basis for requirements model. Finally, the implementation of software system was given.

  13. Pneumatically-powered hand tool used for cutting bolts during bone-fixing in surgery

    OpenAIRE

    Cool, J.C.; Rijnsaardt K.A.

    1996-01-01

    Abstract of NL 1000849 (C2) The tool has at least one pneumatic motor (1a, 1b), transmission (2) and regulator. The motor(s) can be of the piston and cylinder type producing reciprocating motion or of the rotary type. The tool is powered by a commercially-available gas cylinder containing 16g of CO2 at a pressure of 56 bar. Illustrated is a surgical implement to crop bone-fixing bolts. The bolt end is inserted in the hole (7) to enter the eccentric bore (9) of the inner rod (8). The rod rotat...

  14. The Extended Thermodynamic Phase Structure of Taub-NUT and Taub-Bolt

    CERN Document Server

    Johnson, Clifford V

    2014-01-01

    We study aspects of the extended gravitational thermodynamics for the Taub-NUT and Taub-Bolt geometries in four dimensional locally anti-de Sitter spacetime, where the cosmological constant is treated as a dynamical pressure. Attention is paid to the phase structure in the (p,T) plane, which has a line of first order phase transitions extending from the origin. We argue for a dynamical interpretation of the unstable physics in the negative specific heat region. A deformation corresponding to a dyonic Taub-NUT/Bolt system is also explored, and the effect of the deformation on the phase diagram is characterised.

  15. Ultrasonic measurement on RPV stud-bolt loading under hot transient of Qinshan NPP

    International Nuclear Information System (INIS)

    It is a continuation of research work for sealing analysis and tests on the PRV of PWR. It expounds that the key of solving thermal transient sealing problem lies in giving the thermal increment of stud-bolt fatigue life and transient loading spectrum for vessel analysis. The authors recounted the fundamental works and main results of ultrasonic measurement on RPV stud-bolt loading on the reactor of Qinshan Nuclear Power Plant. The measuring capability exceeds 1 m length and 300 degree C temperature. Therefore, it is possible to be used in the field of NPP

  16. Response of garlic (Allium sativum L.) bolting and bulbing to temperature and photoperiod treatments.

    Science.gov (United States)

    Wu, Cuinan; Wang, Mengyi; Cheng, Zhihui; Meng, Huanwen

    2016-01-01

    This research was conducted to evaluate the effect of temperature and photoperiod treatments on the bolting and bulb formation of three local garlic cultivars (cvs) in two consecutive years. Naturally vernalized plants of cvs G107, G025 and G064 were transplanted into growth chambers and subjected to various combinations of temperature [T15/10, 15°C/10°C; T20/15, 20°C/15°C and T25/18, 25°C/18°C (day/night)] and photoperiod (L8, 8 h and L14,14 h) treatments. Plant growth, endogenous phytohormone and methyl jasmonate (MeJA) levels, along with the bolting and yield of garlic were evaluated. The experimental results from two consecutive years indicated that higher temperature (20°C or 25°C) and longer photoperiod (14 h) treatments significantly enhanced the garlic bolting, bulbing and cloving with a shorter growth period and a higher bulb weight. Moreover, the endogenous phytohormone and MeJA levels in the test plants were significantly increased by the higher temperature (25°C for the phytohormone level; 20°C for the MeJA level) and longer photoperiod [14 h, except for abscisic acid (ABA), which had the highest level at 8 h] conditions and were decreased by the lowest test temperature (15°C) and shorter photoperiod (8 h, except for ABA) conditions. This response coincided with that of the bulbing index, bolting rate, growth period and bulb weight. In addition, plants treated under the conditions of 20°C/15°C-14 h and 25°C/18°C-14 h produced the highest phytohormone levels (except for ABA) for cvs G025 and G064, respectively, and showed the best bolting and bulbing behavior. It is reasonable to assume that endogenous phytohormone (especially gibberellic acid) and MeJA levels are highly related to garlic bolting and bulbing, which might lead to the different responses of the three studied cultivars to the combination of temperature and photoperiod treatments. Furthermore, cvs G107 and G025 bolt well and have better bulb formation under 20

  17. Thermal conductance measurements of bolted copper joints for SuperCDMS

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, R. L. [Fermilab; Tatkowski, G [Fermilab; Ruschman, M. [Fermilab; Golwala, S. [Caltech; Kellaris, N. [UC, Berkeley; Daal, M. [UC, Berkeley; Hall, J. [PNL, Richland; Hoppe, E. W. [PNL, Richland

    2015-05-22

    Joint thermal conductance testing has been undertaken for bolted copper to copper connections from 60 mK to 26 K. This testing was performed to validate an initial design basis for the SuperCDMS experiment, where a dilution refrigerator will be coupled to a cryostat via multiple bolted connections. Copper used during testing was either gold plated or passivated with citric acid to prevent surface oxidation. Results obtained are well fit by a power law regression of joint thermal conductance to temperature and match well with data collected during a literature review.

  18. Degradation theories of concrete and development of a new deviatoric model in incremental tangent formulation: limit analysis applied to case of anchor bolts embedded in concrete

    International Nuclear Information System (INIS)

    This research is achieved in the general framework of the study of the concrete behaviour. It has for objective the development of a new behaviour model satisfying to the particular requirements for an industrial exploitation. After the analysis of different existent models, a first development has concerned models based on the smeared crack theory. A new formulation of the theory permitted to overcome the stress locking problem. However, the analysis showed the persistence of some limits inert to this approach in spite of this improvement. Then, an analysis of the physical mechanisms of the concrete degradation has been achieved and permitted to develop the new damage model MODEV. The general formulation of this model is based on the theory of the thermodynamics and applied to the case of the heterogeneous and brittle materials. The MODEV model considers two damage mechanisms: extension and sliding. The model considers also that the relative tangent displacement between microcracks lips is responsible of the strain irreversibility. Thus, the rate of inelastic strain becomes function of the damage and the heterogeneity index of the material. The unilateral effect is taken in account as an elastic hardening or softening process according to re-closing or reopening of cracks. The model is written within the framework of non standard generalised materials in incremental tangent formulation and implemented in the general finite element code SYMPHONIE. The validation of the model has been achieved on the basis of several tests issued from the literature. The second part of this research has concerned the development of the CHEVILAB software. This simulation tool based on the limit analysis approach permit the evaluation of the ultimate load capacity of anchors bolts. The kinematics approach of the limit analysis has been adapted to the problem of anchors while considering several specific failure mechanisms. This approach has been validated then by comparison with the

  19. 煤矿建井施工锚杆支护探析%Built on Coal Mine Well Construction Bolting

    Institute of Scientific and Technical Information of China (English)

    王丹净

    2013-01-01

    This paper built around the coal mine well construction bolting, introduced the principle of the bolt supporting role; analysis to identify bolting parameters, the existing several bolting design method for advantages and disadvantages analysis; this paper discusses how to for bolting project construction and inspection.%文章围绕煤矿建井施工锚杆支护,介绍了锚杆支护的作用原理;分析确定锚杆支护参数,对目前存在的几种锚杆支护设计方法进行优缺点分析;阐述如何进行锚杆支护工程的施工和检验。

  20. Statistical time series methods for damage diagnosis in a scale aircraft skeleton structure: loosened bolts damage scenarios

    International Nuclear Information System (INIS)

    A comparative assessment of several vibration based statistical time series methods for Structural Health Monitoring (SHM) is presented via their application to a scale aircraft skeleton laboratory structure. A brief overview of the methods, which are either scalar or vector type, non-parametric or parametric, and pertain to either the response-only or excitation-response cases, is provided. Damage diagnosis, including both the detection and identification subproblems, is tackled via scalar or vector vibration signals. The methods' effectiveness is assessed via repeated experiments under various damage scenarios, with each scenario corresponding to the loosening of one or more selected bolts. The results of the study confirm the 'global' damage detection capability and effectiveness of statistical time series methods for SHM.

  1. Beam-to-beam joints with bolted end-plate connections concerning steel platforms Angra 2 NPP

    International Nuclear Information System (INIS)

    The paper presents adopted end-plates connections as structural solution for joints in steel platforms subjected to seismic loads as well as exceptional loads due to postulated piping ruptures. The beam-to-beam bolted end-plate connections designed for Angra 2 NPP were based in allowable stresses design. Also, usual assumptions and methods in the engineering practice, concerning steel platforms for german power plants in the 80's, were considered. The adopted method is compared with the proceedings according to Eurocode 3 - Part 1-8 to verify safety margins between old and new concept. The target of this comparison is to be sure that the adopted design is enough conservative to be adopted for the next NPP - Angra 3 (similar to Angra 2), whose construction will start in 2009. (author)

  2. UML for Early Requirements Elicitation: A Regulation based Approach

    OpenAIRE

    Regev, Gil; Wegmann, Alain

    2002-01-01

    Early requirements of information systems are often understood in terms of the elicitation of stakeholders' high-level goals to be supported by the system under discussion. Stakeholders' goals are considered as the ultimate explanation of requirements. It is assumed that the notion of a high-level goal is natural and that high-level goals need no explanation with regard to their origins. We believe that these assumptions result in the definition of inadequate goals. We propose an organization...

  3. Section 3: Quality and Value-Based Requirements

    Science.gov (United States)

    Mylopoulos, John

    Traditionally, research and practice in software engineering has focused its attention on specific software qualities, such as functionality and performance. According to this perspective, a system is deemed to be of good quality if it delivers all required functionality (“fitness-for-purpose”) and its performance is above required thresholds. Increasingly, primarily in research but also in practice, other qualities are attracting attention. To facilitate evolution, maintainability and adaptability are gaining popularity. Usability, universal accessibility, innovativeness, and enjoyability are being studied as novel types of non-functional requirements that we do not know how to define, let alone accommodate, but which we realize are critical under some contingencies. The growing importance of the business context in the design of software-intensive systems has also thrust economic value, legal compliance, and potential social and ethical implications into the forefront of requirements topics. A focus on the broader user environment and experience, as well as the organizational and societal implications of system use, thus has become more central to the requirements discourse. This section includes three contributions to this broad and increasingly important topic.

  4. Safety integrity requirements for computer based I ampersand C systems

    International Nuclear Information System (INIS)

    In order to take into account increasingly demanding functional requirements, many instrumentation and control (I ampersand C) systems in nuclear power plants are implemented with computers. In order to ensure the required safety integrity of such equipment, i.e., to ensure that they satisfactorily perform the required safety functions under all stated conditions and within stated periods of time, requirements applicable to these equipment and to their life cycle need to be expressed and followed. On the other hand, the experience of the last years has led EDF (Electricite de France) and its partners to consider three classes of systems and equipment, according to their importance to safety. In the EPR project (European Pressurized water Reactor), these classes are labeled E1A, E1B and E2. The objective of this paper is to present the outline of the work currently done in the framework of the ETC-I (EPR Technical Code for I ampersand C) regarding safety integrity requirements applicable to each of the three classes. 4 refs., 2 figs

  5. Deriving future oriented research and competence requirements based on scenarios

    DEFF Research Database (Denmark)

    Sonne, Anne-Mette; Harmsen, Hanne; Jensen, Birger Boutrup

    overnight. Consequently companies need to try to be foresighted with regards to what is required to operate successfully not only today but also tomorrow and in five and ten years. Hence, companies are faced with trying to assess how to best prepare themselves for a tomorrow that they can only guess about...... scenarios for this purpose. Most scenario studies report mostly on the scenario construction, were as we want to focus on the suitability of scenario methods as a mean of deducting competence requirements and research needs. Also scenario techniques have mostly been used on either a company level or a macro......The key to a company's survival lies in its ability to adapt itself to an ever changing world. A company's knowledge and competencies must be fitted to the requirements of the environment in which it operates. However, the kind of competencies that ensures a company's survival are not acquired...

  6. Seismic Properties of Moment-resisting Timber Joints with a Combination of Bolts and Nails

    Directory of Open Access Journals (Sweden)

    Awaludin A.

    2011-01-01

    Full Text Available Improvement of cyclic or dynamic performance of timber connections has been intensively conducted since the overall response of wooden structures is merely a function of joint performance. For a bolted joint, filling the lead-hole clearance with epoxy resin or gluing high embedding-strength materials at the interface of the individual timber member are probably the most common methods. This study presents cyclic test results of moment-resisting joints with a combination of bolts and nails. The nails were placed closer to the joint centroid than the bolts, acting as additional fasteners and were expected to improve the seismic performance of the joints. Static-cyclic test results confirmed the increase of joint stiffness and moment resistance due to the additional nails. The nails contribute to the increase of hysteretic damping significantly though pinching behavior or narrowing the hysteresis loops close to zero rotation points was still observed. The results indicated that contribution of nails or bolts on moment resistance and hysteretic damping can be superimposed.

  7. The baffle-barrel-bolting analysis program: evolution and technical accomplishments

    Energy Technology Data Exchange (ETDEWEB)

    Schwirian, R.E.; Forsyth, D.R.; Snyder, M.D.; Bhandari, D.R.; Barsic, J.A.; Rabenstein, W.D. [Westinghouse Electric Company, Pittsburgh, Pennsylvania (United States)

    2001-07-01

    In Westinghouse pressurized water reactors (PWR) the reactor core is surrounded by baffle plates, which provide lateral restraint for the fuel assemblies at the core boundary. Baffle plates are attached to horizontal supports called former plates by baffle-former bolts. The formers are attached to the core barrel which also provides vertical support for the core. The B3 analysis program addresses the possibility of reduced baffle-former bolting in Westinghouse U.S. domestic plant designs with respect to the relevant design criteria. Since safety is the overriding motivation for the program, faulted events have received the most in-depth attention. This focus has been reinforced by the fact that the loads produced by the loss-of-coolant-accident (LOCA) have usually been the most limiting of all those considered. Consequently, much of the presentation below deals with the development of analysis techniques and acceptance criteria to demonstrate that LOCA-induced loads on the bolts and the fuel assemblies will be acceptable with significantly reduced baffle-former bolting. A discussion of the other faulted, normal, and upset analyses performed as part of the program will also be presented. (author)

  8. Pull-out test of stud bolts embedded in concrete under an in-plane force

    International Nuclear Information System (INIS)

    There are many steel plates with stud bolts embedded in the R C walls of a nuclear reactor building to support equipment and piping. Under a earthquake, the steel plates are submitted to an out-of-plane force due to the inertia force acting upon equipment and piping. Furthermore, the walls are submitted to an in-plane force, and cracks may occur. A large number of experimental studies have been carried out on the pull-out strength of stud bolts embedded in concrete. Few studies have been performed to understand the strength of stud bolts embedded in concrete under an in-plane force and, further, not any one on the strength for concrete under in-plane force simultaneously to stud bolts under out-of-plane force. This paper describes a test performed to understand the pull-out strength determined by this interaction of in-plane and out-of-plane forces. (author). 5 refs., 9 figs., 5 tabs

  9. Review and synthesis of stress intensity factor solutions applicable to cracks in bolts

    International Nuclear Information System (INIS)

    The available literature for stress intensity factor solutions for cracks in round bars, both threaded and unthreaded, subjected to either tension or bending, is reviewed. The results are synthesized into a form that is appropriate for the analysis of bolts and studs. (author)

  10. Residual Strength of Glued-in Bolts After 9 Years In Situ Loading

    DEFF Research Database (Denmark)

    Pedersen, Martin Bo Uhre; Clorius, Christian Odin; Damkilde, Lars;

    1996-01-01

    In 1993 one of the wooden blades of the Nibe-B windmill was struck by lightning and subsequently demounted after 9 years of use. The mishap offered a unique opportunity to investigate the residual strength of the 28 glued-in bolts used to form the blade to rotor hub connection.The test method...

  11. Mechanical tests of the bolt of the gripper latch on the control rod cluster

    International Nuclear Information System (INIS)

    Failure analysis and mechanical testing indicate that control rod drive mechanisms malfunctioning by 1995-96 is due to rupture by fatigue of a bolt inside the stationary gripper assembly. Fatigue is enhanced by free working following surface adaptation and unscrewing of the assembly. These results are taken into account for the choice of a new anti-rotation device. (authors)

  12. 77 FR 32698 - Proposed Extension of Existing Information Collection; Safety Standards for Roof Bolts in Metal...

    Science.gov (United States)

    2012-06-01

    ... for Roof Bolts in Metal and Nonmetal Mines and Underground Coal Mines AGENCY: Mine Safety and Health... underground metal, nonmetal, and coal mines or falls of highwall in surface metal and nonmetal mines, are... underground metal and nonmetal mines and underground coal mines. MSHA is particularly interested in...

  13. Improved bolt models for use in global analyses of storage and transportation casks subject to extra-regulatory loading

    International Nuclear Information System (INIS)

    Transportation and storage casks subjected to extra-regulatory loadings may experience large stresses and strains in key structural components. One of the areas susceptible to these large stresses and strains is the bolted joint retaining any closure lid on an overpack or a canister. Modeling this joint accurately is necessary in evaluating the performance of the cask under extreme loading conditions. However, developing detailed models of a bolt in a large cask finite element model can dramatically increase the computational time, making the analysis prohibitive. Sandia National Laboratories used a series of calibrated, detailed, bolt finite element sub-models to develop a modified-beam bolt-model in order to examine the response of a storage cask and closure to severe accident loadings. The initial sub-models were calibrated for tension and shear loading using test data for large diameter bolts. Next, using the calibrated test model, sub-models of the actual joints were developed to obtain force-displacement curves and failure points for the bolted joint. These functions were used to develop a modified beam element representation of the bolted joint, which could be incorporated into the larger cask finite element model. This paper will address the modeling and assumptions used for the development of the initial calibration models, the joint sub-models and the modified beam model

  14. A contribution to the selection and calculation of screws in high duty bolted joints

    International Nuclear Information System (INIS)

    The paper deals with the assessment of the correct design methodology that allows selecting the appropriate screw (in terms of reference nominal diameter) to be used in high duty bolted joints. Some Standards or Guidelines are analysed and discussed although the most complete appears the VDI-2230 (February 2003); in many cases the simplifications adopted can only be effective in presence of steel screws clamped on steel plates (often considered as rigid in comparison to the screw) and by considering coefficients of friction which vary in a narrow range (0.15–0.20). Hence, the increasing use of lightweight materials in recent years (e.g. magnesium, aluminium and titanium), as well as design optimisations, is forcing the screw designers to perform an attentive selection of the most appropriate fastening connection. For these reasons, this contribution tries to give a compressed, but comprehensive and clearly structured view about the maximum equivalent stress acting on the bolt as a function of the actual joint parameters (e.g. ratio between tensile and shear forces acting on the joint, ratio between bolt and plates stiffness, effect of coefficient of friction, static or fatigue loads). Highlights: ► The paper presents an innovative method for selecting of ISO metric screws. ► The screws have to be used in high duty bolted joints for lightweight connections. ► Some standards have been deeply analysed. ► The nominal stress acting on the bolt has been accurately determined. ► The most important parameter to be actually controlled is the thread coefficient of friction.

  15. Higher Accurate Estimation of Axial and Bending Stiffnesses of Plates Clamped by Bolts

    Science.gov (United States)

    Naruse, Tomohiro; Shibutani, Yoji

    Equivalent stiffness of clamped plates should be prescribed not only to evaluate the strength of bolted joints by the scheme of “joint diagram” but also to make structural analyses for practical structures with many bolted joints. We estimated the axial stiffness and bending stiffness of clamped plates by using Finite Element (FE) analyses while taking the contact condition on bearing surfaces and between the plates into account. The FE models were constructed for bolted joints tightened with M8, 10, 12 and 16 bolts and plate thicknesses of 3.2, 4.5, 6.0 and 9.0 mm, and the axial and bending compliances were precisely evaluated. These compliances of clamped plates were compared with those from VDI 2230 (2003) code, in which the equivalent conical compressive stress field in the plate has been assumed. The code gives larger axial stiffness for 11% and larger bending stiffness for 22%, and it cannot apply to the clamped plates with different thickness. Thus the code shall give lower bolt stress (unsafe estimation). We modified the vertical angle tangent, tanφ, of the equivalent conical by adding a term of the logarithm of thickness ratio t1/t2 and by fitting to the analysis results. The modified tanφ can estimate the axial compliance with the error from -1.5% to 6.8% and the bending compliance with the error from -6.5% to 10%. Furthermore, the modified tanφ can take the thickness difference into consideration.

  16. Tornado wind-loading requirements based on risk assessment techniques

    International Nuclear Information System (INIS)

    Regulations require that nuclear power plants be protected from tornado winds. If struck by a tornado, a plant must be capable of safely shutting down and removing decay heat. Probabilistic techniques are used to show that risk to the public from the US Department of Energy (DOE) SP-100 reactor is acceptable without tornado hardening parts of the secondary system. Relaxed requirements for design wind loadings will result in significant cost savings. To demonstrate an acceptable level of risk, this document examines tornado-initiated accidents. The two tornado-initiated accidents examined in detail are loss of cooling resulting in core damage and loss of secondary system boundary integrity leading to sodium release. Loss of core cooling is analyzed using fault/event tree models. Loss of secondary system boundary integrity is analyzed by comparing the consequences to acceptance criteria for the release of radioactive material or alkali metal aerosol

  17. Tornado wind-loading requirements based on risk assessment techniques

    International Nuclear Information System (INIS)

    Regulations require that nuclear power plants be protected from tornado winds. If struck by a tornado, a plant must be capable of safely shutting down and removing decay heat. Probabilistic techniques are used to show that risk to the public from the US Department of Energy (DOE) SP-100 reactor is acceptable without tornado hardening parts of the secondary system. Relaxed requirements for design wind loadings will result in significant cost savings. To demonstrate an acceptable level of risk, this document examines tornado-initiated accidents. The two tornado-initiated accidents examined in detail are loss of cooling resulting in core damage and loss of secondary system boundary integrity leading to sodium release. Loss of core cooling is analyzed using fault/event tree models. Loss of secondary system boundary integrity is analyzed by comparing the consequences to acceptance criteria for the release of radioactive material or alkali metal aerosol. 4 refs., 4 figs

  18. Requirements of a Web-based experiment management system.

    OpenAIRE

    Jakobovits, R.; Soderland, S. G.; Taira, R. K.; Brinkley, J.F.

    2000-01-01

    Recent advances in tools for scientific data acquisition, visualization, and analysis have lead to growing information management problems for medical research laboratories. An exponential increase in the volume of data, combined with a proliferation of heterogeneous formats and autonomous systems, has driven the need for flexible and powerful Experiment Management Systems (EMS). This paper provides a detailed analysis of the informatics requirements of an EMS, and proposes a new type of midd...

  19. Risk-Based Confidentiality Requirements Specification for Outsourced IT Systems

    OpenAIRE

    Morali, Ayse; Wieringa, Roel

    2010-01-01

    Today, companies are required to be in control of their IT assets, and to provide proof of this in the form of independent IT audit reports. However, many companies have outsourced various parts of their IT systems to other companies, which potentially threatens the control they have of their IT assets. To provide proof of being in control of outsourced IT systems, the outsourcing client and outsourcing provider need a written service level agreement (SLA) that can be audited by an independen...

  20. Evaluation of motion management strategies based on required margins

    International Nuclear Information System (INIS)

    Strategies for delivering radiation to a moving lesion each require a margin to compensate for uncertainties in treatment. These motion margins have been determined here by separating the total uncertainty into components. Probability density functions for the individual sources of uncertainty were calculated for ten motion traces obtained from the literature. Motion margins required to compensate for the center of mass motion of the clinical treatment volume were found by convolving the individual sources of uncertainty. For measurements of position at a frequency of 33 Hz, system latency was the dominant source of positional uncertainty. Averaged over the ten motion traces, the motion margin for tracking with a latency of 200 ms was 4.6 mm. Gating with a duty cycle of 33% required a mean motion margin of 3.2–3.4 mm, and tracking with a latency of 100 ms required a motion margin of 3.1 mm. Feasible reductions in the effects of the sources of uncertainty, for example by using a simple prediction algorithm to anticipate the lesion position at the end of the latency period, resulted in a mean motion margin of 1.7 mm for tracking with a latency of 100 ms, 2.4 mm for tracking with a latency of 200 ms, and 2.1–2.2 mm for the gating strategies with duty cycles of 33%. A crossover tracking latency of 150 ms was found, below which tracking strategies could take advantage of narrower motion margins than gating strategies. The methods described here provide a means to guide selection of a motion management strategy for a given patient. (paper)

  1. Characterising Concurrent Tests Based on Message Sequence Chart Requirements

    OpenAIRE

    Mitchell, Bill

    2001-01-01

    MSC-s specifying system requirements can be used to generate test scripts in languages such as TTCN. In 1996 TTCN was extended in order to describe concurrent test scripts. We give a characterisation of which concurrent tests can be executed by parallel test components (PTC-s) acting in concert. We also characterise when the PTC-s give the correct test result verdict.

  2. Dependency Graph for Requirements Structuring based on Guidance Ontology

    OpenAIRE

    DARRAGI, Nesrine; Collart-Dutilleul, Simon; El Koursi, El Miloudi; Bon, Philippe

    2013-01-01

    The modeling process aims to define and analyse requirements for testing physical scale systems such as robotic surgery machines, railway signalling and control systems, nuclear reactor control systems, etc... These safety-critical systems whose failure may result in severe human or physical damage, are designed to be testable and verifiable before their implementation. To understand the system specifications and its functionalities, different types of models are used and each one reflects a ...

  3. 非金属垫片螺栓法兰连接寿命评价%Life Assessment of Non-metallic Gasket Bolted Flanged Connections 

    Institute of Scientific and Technical Information of China (English)

    孙振国; 顾伯勤

    2011-01-01

    分析非金属垫片密封的时效特性,考虑高温条件下材料退化和垫片载荷松弛过程对密封性能的影响,依据多孔介质理论,建立非金属垫片密封的时效泄漏模型.将螺栓法兰连接系统寿命划分为密封寿命和部件寿命.提出密封寿命试验方法,在考虑垫片泄漏特性变化的基础上,基于指标泄漏率分析螺栓法兰连接系统密封寿命;基于蠕变和疲劳损伤准则分析高温螺栓的剩余寿命,探讨螺栓法兰连接系统的密封寿命和各部件寿命之间的关系.建立螺栓法兰连接系统的寿命预测最弱环模型,将垫片的变形特性和泄漏特性统一于螺栓法兰连接系统中进行研究,提出基于指标泄漏率和结构完整性的螺栓法兰连接系统寿命评价方法.%The time-correlated leakage characteristic of nonmetallic gaskets was analyzed. Considering the effect of the gasket compressive stress relaxation and the deterioration of material on gasket sealing performance at elevated temperature,a time-correlated leakage prediction model of non-metallic gasket sealing connections based on the porous medium theory was proposed. The life of bolted flanged connections was divided into sealing life and component life. A testing method of sealing life was put forward,the sealing life can be predicted based on target leakage rate in considering the change of gasket leakage characteristic,and the life of bolts can be obtained based on creep and fatigue damage criterion. The relationship between sealing life and component life of sealing system was discussed, and a weakest-link model for predicting the life of bolted flanged connections was established. A life evaluation method of bolted flanged connections based on the target leakage rate and the structural integrity was proposed, in which the deformation and leakage characteristic of the sealing system were both taken into consideration.

  4. 30 CFR 7.98 - Technical requirements.

    Science.gov (United States)

    2010-07-01

    ... required to provide explosion-proof features, provided that failure of the connection activates the safety... exhaust system and shall be threaded to ensure that all specified bolts or screws will not bottom even if... to the interior of an intake or exhaust system and shall be threaded to ensure that all...

  5. Failure of intramedullary femoral nail with segmental breakage of distal locking bolts: a case report and review of the literature

    Institute of Scientific and Technical Information of China (English)

    Sameer Aggerwal; Nitesh Gahlot; Uttam C. Saini; Kamal Bali

    2011-01-01

    Breakage of locking bolts is an important cause of interlocking nail failure in femoral fractures. It usually occurs in the form of single breakage in one of the distal bolts of the nail or nail breakage around the distal locking hole. Here we report an unusual case of intramedullary femoral nail failure with segmental breakage of both the distal locking bolts. Such a scenario usually complicates further management. We successfully managed this case with exchange nailing without bone grafting. Here we briefly reviewed the literature regarding such an unusual presentation and discussed in detail the possible etiology of such a presentation and the management options when facing such a complex situation.

  6. Water resource requirements of corn-based ethanol

    OpenAIRE

    Mubako, Stanley; Lant, Christopher L.

    2008-01-01

    Ethanol derived from fermentation of corn is a very water-intensive product with water to ethanol mass ratios of 927 to 1178 and volumetric ratios of 1174 to 1492 for the major rainfed corn-growing U.S. states of Illinois and Iowa and the leading irrigated corn-growing state of Nebraska, respectively. Over 99% of water requirements are for growing corn feed stocks, with 99% of that amount in Illinois and Iowa, occurring as evapotranspiration of rainfall in corn fields, and 60% as evapotranspi...

  7. Diversity requirements for safety critical software-based automation systems

    International Nuclear Information System (INIS)

    System vendors nowadays propose software-based systems even for the most critical safety functions in nuclear power plants. Due to the nature and mechanisms of influence of software faults new methods are needed for the safety and reliability evaluation of these systems. In the research project 'Programmable automation systems in nuclear power plants (OHA)' various safety assessment methods and tools for software based systems are developed and evaluated. This report first discusses the (common cause) failure mechanisms in software-based systems, then defines fault-tolerant system architectures to avoid common cause failures, then studies the various alternatives to apply diversity and their influence on system reliability. Finally, a method for the assessment of diversity is described. Other recently published reports in OHA-report series handles the statistical reliability assessment of software based (STUK-YTO-TR 119), usage models in reliability assessment of software-based systems (STUK-YTO-TR 128) and handling of programmable automation in plant PSA-studies (STUK-YTO-TR 129)

  8. Testing and evaluation of Vespel up to 450 deg F when used in nuts and bolts as a self-locking element

    Science.gov (United States)

    Wood, C. M.

    1984-01-01

    The object of this investigation was to evaluate Vespel for potential application on the Solid Rocket Booster to replace all-metal deformed self-locking nuts and anchor nuts and be used as self-locking elements for bolts and screws. The Vespel self-locking elements were tested for prevailing torque retention at room temperature, after heating to 450 F and exposure for 3 hr, breakaway torque at 450 F and for vibration at a level consistent with the maximum expected on the SRB at lift-off and reentry. The investigation revealed Vespel has properties that can provide a self-locking capability for threaded fasteners up to 450 F and it can be used in nuts and anchor nuts for installation on the SRB. Vespel elements in bolts did not meet all our SRB requirements for reuse, however, we have defined a design for Vespel elements in nuts/anchor nuts that fully meets all requirements. It is recommended that No. 1, 1/4 in. and 5/16 in. nuts/anchor nuts be procured for use on the SRB. This system will eliminate the galling problems now encountered and achieve a much higher reuse life than the present deformed nut design.

  9. Lunar lander stage requirements based on the Civil Needs Data Base

    Science.gov (United States)

    Mulqueen, John A.

    1992-01-01

    This paper examines the lunar lander stages that will be necessary for the future exploration and development of the Moon. Lunar lander stage sizing is discussed based on the projected lunar payloads listed in the Civil Needs Data Base. Factors that will influence the lander stage design are identified and discussed. Some of these factors are (1) lunar orbiting and lunar surface lander bases; (2) implications of direct landing trajectories and landing from a parking orbit; (3) implications of landing site and parking orbit; (4) implications of landing site and parking orbit selection; (5) the use of expendable and reusable lander stages; and (6) the descent/ascent trajectories. Data relating the lunar lander stage design requirements to each of the above factors and others are presented in parametric form. These data will provide useful design data that will be applicable to future mission model modifications and design studies.

  10. Automated analysis of security requirements through risk-based argumentation

    NARCIS (Netherlands)

    Yu, Yijun; Franqueira, Virginia N.L.; Tun, Thein Tan; Wieringa, Roel J.; Nuseibeh, Bashar

    2015-01-01

    Computer-based systems are increasingly being exposed to evolving security threats, which often reveal new vulnerabilities. A formal analysis of the evolving threats is difficult due to a number of practical considerations such as incomplete knowledge about the design, limited information about atta

  11. Risk and Business Goal Based Security Requirement and Countermeasure Prioritization

    OpenAIRE

    Herrmann, Andrea; Morali, Ayse; Etalle, Sandro; Wieringa, Roel

    2012-01-01

    Companies are under pressure to be in control of their assets but at the same time they must operate as efficiently as possible. This means that they aim to implement “good-enough security” but need to be able to justify their security investment plans. Currently companies achieve this by means of checklist-based security assessments, but these methods are a way to achieve consensus without being able to provide justifications of countermeasures in terms of business goals. But such justificat...

  12. Games based on active NFC objects : model and security requirements

    OpenAIRE

    Fortat, Florent; LAURENT, Maryline; Simatic, Michel

    2015-01-01

    Cheating in video games is a critical financial matter for game developers. With games now integrating physical objects through NFC, new cheating techniques have emerged, including characteristic boosting of the objects, duplication of objects and introduction of new unauthorized objects. In this paper, we address this problem for games based on active NFC objects. Having active objects in a game allows for new possibilities of interaction yet to be seen, including offline interactions betwee...

  13. A History-based Estimation for LHCb job requirements

    CERN Document Server

    Rauschmayr, Nathalie

    2015-01-01

    The main goal of a Workload Management System (WMS) is to find and allocate resources for the given tasks. The more and better job information the WMS receives, the easier will be to accomplish its task, which directly translates into higher utilization of resources. Traditionally, the information associated with each job, like expected runtime, is defined beforehand by the Production Manager in best case and fixed arbitrary values by default. In the case of LHCb's Workload Management System no mechanisms are provided which automate the estimation of job requirements. As a result, much more CPU time is normally requested than actually needed. Particularly, in the context of multicore jobs this presents a major problem, since single- and multicore jobs shall share the same resources. Consequently, grid sites need to rely on estimations given by the VOs in order to not decrease the utilization of their worker nodes when making multicore job slots available. The main reason for going to multicore jobs is the red...

  14. A Machine Learning Based Analytical Framework for Semantic Annotation Requirements

    Directory of Open Access Journals (Sweden)

    Hamed Hassanzadeh

    2011-04-01

    Full Text Available The Semantic Web is an extension of the current web in which information is given well-defined meaning.The perspective of Semantic Web is to promote the quality and intelligence of the current web by changingits contents into machine understandable form. Therefore, semantic level information is one of thecornerstones of the Semantic Web. The process of adding semantic metadata to web resources is calledSemantic Annotation. There are many obstacles against the Semantic Annotation, such as multilinguality,scalability, and issues which are related to diversity and inconsistency in content of different web pages.Due to the wide range of domains and the dynamic environments that the Semantic Annotation systemsmust be performed on, the problem of automating annotation process is one of the significant challenges inthis domain. To overcome this problem, different machine learning approaches such as supervisedlearning, unsupervised learning and more recent ones like, semi-supervised learning and active learninghave been utilized. In this paper we present an inclusive layered classification of Semantic Annotationchallenges and discuss the most important issues in this field. Also, we review and analyze machinelearning applications for solving semantic annotation problems. For this goal, the article tries to closelystudy and categorize related researches for better understanding and to reach a framework that can mapmachine learning techniques into the Semantic Annotation challenges and requirements.

  15. Laser wakefield accelerator based light sources: potential applications and requirements

    Energy Technology Data Exchange (ETDEWEB)

    Albert, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). NIF and Photon Sciences; Thomas, A. G. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences; Mangles, S. P.D. [Imperial College, London (United Kingdom). Blackett Lab.; Banerjee, S. [Univ. of Nebraska, Lincoln, NE (United States); Corde, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Flacco, A. [ENSTA, CNRS, Ecole Polytechnique, Palaiseau (France); Litos, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Neely, D. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Viera, J. [Univ. of Lisbon (Portugal). GoLP-Inst. de Plasmas e Fusao Nuclear-Lab. Associado; Najmudin, Z. [Imperial College, London (United Kingdom). Blackett Lab.; Bingham, R. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Joshi, C. [Univ. of California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Katsouleas, T. [Duke Univ., Durham, NC (United States). Platt School of Engineering

    2015-01-15

    In this article we review the prospects of laser wakefield accelerators as next generation light sources for applications. This work arose as a result of discussions held at the 2013 Laser Plasma Accelerators Workshop. X-ray phase contrast imaging, X-ray absorption spectroscopy, and nuclear resonance fluorescence are highlighted as potential applications for laser-plasma based light sources. We discuss ongoing and future efforts to improve the properties of radiation from plasma betatron emission and Compton scattering using laser wakefield accelerators for these specific applications.

  16. Laser wakefield accelerator based light sources: potential applications and requirements

    International Nuclear Information System (INIS)

    In this article we review the prospects of laser wakefield accelerators as next generation light sources for applications. This work arose as a result of discussions held at the 2013 Laser Plasma Accelerators Workshop. X-ray phase contrast imaging, X-ray absorption spectroscopy, and nuclear resonance fluorescence are highlighted as potential applications for laser-plasma based light sources. We discuss ongoing and future efforts to improve the properties of radiation from plasma betatron emission and Compton scattering using laser wakefield accelerators for these specific applications.

  17. Applied on bolting-cable anchor support of full-seam roadway in weaker thick coal seam

    Institute of Scientific and Technical Information of China (English)

    赵庆彪; 张生华; 郭励生

    2003-01-01

    The designing method and the supporting mechanism of both bolt and small cable anchor for full-seam roadway in the weaker thick coal seam are systematically analyzed, and the construction technology and the supporting results are briefly summarized.

  18. 30 CFR 764.21 - Data base and inventory system requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Data base and inventory system requirements... SURFACE COAL MINING OPERATIONS § 764.21 Data base and inventory system requirements. (a) The regulatory authority shall develop a data base and inventory system which will permit evaluation of whether...

  19. Non-Destructive Evaluation of Rock Bolts Associated With Optical Strain Sensors at the Homestake Gold Mine

    Science.gov (United States)

    Kogle, M. M.; Fratta, D.; Wang, H. F.; Geox^Tm

    2010-12-01

    Fiber-Bragg Grating (FBG) optical strain sensors have been installed in the former Homestake Gold Mine (Lead, SD) as part of an early science project at the Deep Underground Science and Engineering Laboratory (DUSEL). FBG sensors are anchored within an alcove at the 4100’ level of the mine using rock bolts and coupled to the rock mass with resin epoxy and cement grout. The quality of the coupling between the rock bolt and the rock mass is essential to assure that true rock mass strains are being recorded. To evaluate the integrity of the installed rock bolt system, guided ultrasonic waves can be used as a non-destructive monitoring system. The propagation of reflected ultrasonic waves capture information about the degree of coupling between the steel rock bolt and resin epoxy/cement grout and between the resin epoxy/cement grout and the surrounding rock mass, and hence the integrity of the installed rock bolt system. In this study, we use the phase velocity obtained from ultrasonic wave propagation to estimate the rock modulus. In our initial testing we generated a broadband elastic wave along the length of a rock bolt anchored in a concrete cylinder while monitoring multiple reflections with a single accelerometer affixed at the exposed end of the rock bolt. The captured waveforms include several reflections that were then analyzed to obtain frequency response, coherence, phase velocity, and damping between multiple reflections. As the wavelength increases, the response captures first elastic properties of the steel and then the combined elastic properties of the rock bolt/rock mass system. Challenges associated with implementing this non-destructive testing technique in rock masses include the generation of wide bandwidth signals having enough strength to produce multiple reflections with high enough signal-to-noise ratios to capture properties of multi-scale systems.

  20. 42CrMo风机塔筒法兰高强度螺栓疲劳寿命分析%Fatigue Life Analysis on 42CrMo High-strength Flange-bolt Used in Wind Turbine Tower Simulator

    Institute of Scientific and Technical Information of China (English)

    何玉林; 吴德俊; 侯海波; 杜静; 李成武

    2012-01-01

    基于Schmidt-Neuper理论,针对风机塔筒法兰高强度合金钢螺栓,建立了将法兰中心载荷时间历程转换为螺栓应力时间历程的公式化方法.依据德国劳埃德船级社规范,对螺栓S-N曲线进行了修正.通过雨流计数法得到应力时间历程的完整循环载荷,再运用Palmgren/Miner线性累积损伤理论得到螺栓的疲劳损伤.同时,还通过有限元法拟合了法兰中心载荷与螺栓应力的公式,并计算了螺栓疲劳损伤.通过将这两种方法得到的结果进行对比,证明了所研究方法的有效性,为风力发电机螺栓的设计提供了参考.%Based on the schmidt-neuper theory, the formulaic method for converting the load time series into the stress time series was set up, which can be used in high-strength alloy steel bolts of wind turbine tower flange. According to the guideline for the certification of wind turbines compiled by Germanischer Uoyd, the S-N curves of the bolts were modified. Rain flow counting method was used to get the complete load cycle of stress time series, and the fatigue damage of the bolts was calculated by using the Palmgren/Miner method. Besides, the formula of the centric load of flange and the bolt stress were also obtained by finite element method, and the fatigue damage of the bolts was calculated. By comparing the results of the two methods, the validity of the method described in the research is proved, which can provide some references for the design of wind turbine bolt

  1. Trust and Privacy Solutions Based on Holistic Service Requirements

    Directory of Open Access Journals (Sweden)

    José Antonio Sánchez Alcón

    2015-12-01

    Full Text Available The products and services designed for Smart Cities provide the necessary tools to improve the management of modern cities in a more efficient way. These tools need to gather citizens’ information about their activity, preferences, habits, etc. opening up the possibility of tracking them. Thus, privacy and security policies must be developed in order to satisfy and manage the legislative heterogeneity surrounding the services provided and comply with the laws of the country where they are provided. This paper presents one of the possible solutions to manage this heterogeneity, bearing in mind these types of networks, such as Wireless Sensor Networks, have important resource limitations. A knowledge and ontology management system is proposed to facilitate the collaboration between the business, legal and technological areas. This will ease the implementation of adequate specific security and privacy policies for a given service. All these security and privacy policies are based on the information provided by the deployed platforms and by expert system processing.

  2. Effect of pre-tensioned rock bolts on stress redistribution around a roadway insight from numerical modeling

    Institute of Scientific and Technical Information of China (English)

    GAO Fu-qiang; KANG Hong-pu

    2008-01-01

    The importance of the pre-tensioned force of rock bolts has been recognized by more and more researchers. To investigate the effect of pre-tensioned rock bolts on stress redistribution around roadways, a numerical analysis was carded out using FLAC3D and a special post-process methodology, using surfer, is proposed to process the numerical simulation results. The results indicate that pre-tensioned rock bolts have a significant effect on stress redistribution around a roadway. In the roof, pre-tensioned rock bolts greatly increase vertical stress; as a result, the strength of the rock mass increased significantly which results in a greater capacity of bearing a large horizontal stress. The horizontal stress decreases in the upper section of the roof, indicating that pre-tensioned rock bolts significantly reduce the coefficient and the size of the region concentration of horizontal stress. At the lateral side, pre-tensioned rock bolts greatly increase the horizontal stress; therefore, the rock mass strength significantly increases which results also in a greater capacity of bearing a large vertical stress. The greater the size of pre-tensioned force, the larger the region of stress redistribution around a roadway is affected and the higher the size of the stress on the roadway surface the more the rock mass strength increases.

  3. Testing of nuclear grade lubricants and their effect on A540 B24 and A193 B7 bolting materials

    International Nuclear Information System (INIS)

    An increase in the number of bolting failures attributed to lubricant/coolant interaction at nuclear power plants has caused a great deal of concern regarding the more judicious use of lubricants by the nuclear power industry. An investigation was performed on eleven commonly used lubricants by the nuclear power industry. The investigation included EDS analysis of the lubricants, notched-tensile constant extension rate testing of bolting materials with the lubricants, frictional testing of the lubricants and weight loss testing of a bonded solid film lubricant. The report generally concludes that there is a significant amount of variance in the mechanial properties of common bolting materials, that MoS2 can hydrolyze to form H2S at 1000C and cause stress corrosion cracking (SCC) of bolting materials, and that the use of copper-containing lubricants can be potentially detrimental to high strength steels in an aqueous environment. Additionally, the testing of various lubricants disclosed that some lubricants contain potentially detrimental elements (e.g. S, Sb) which can promote SCC of the common bolting materials. One of the most significant findings of this report is the observation that both A193 B7 and A540 B24 bolting materials are susceptible to transgranular stress corrosion cracking in demineralized H2O at 2800C in notched tensile tests. 139 figures

  4. PERL - European research project on characterization of gaskets for bolted flange connections

    International Nuclear Information System (INIS)

    Great progress was observed in the European standardization in the last years in the field of the design of floating type bolted flange connections. New design rules were developed (EN 1591) which include new definitions of gasket characteristics for the calculation of floating type flanged joints. In addition a new gasket testing standard was drafted (prEN 13555) which assures a comprehensive characterization of gaskets for bolted flanged joints. This draft standard contains some new features which were examined and validated within the European research project PERL (Pressure Equipment - Reduction of Leak Rate). The gasket testing strategy laid down in prEN 13555 is presented in this paper. Some testing results highlighten the measuring procedures and the evaluation of the gasket characteristics. (orig.)

  5. Failure analysis of the stud bolt of a canned motor pump of heavy water plant, Talcher

    International Nuclear Information System (INIS)

    Detailed investigations have been carried out on the failed stud bolts (made of DIN 1.4021 X 20Cr 13) of a canned motor pump of Heavy Water Plant, Talcher, using metallographic, microhardness testing, scanning electron microscopy and electron probe micro-analysis(EPMA) techniques. The studs had failed in a brittle manner in the mid-length portion. The origin of the fracture has been identified to be a corroded region on the stud surface. Branching cracks propagating through silicon rich inclusions have been noted. Two types of inclusions, one containing Mn and S and other containing S, Mn and O2 have been found in the material. Clusters of large and small inclusions of the above types have been found near the origin of the fracture. It has been concluded that the fracture was caused by corrosion fatigue, initiating at the cluster of inclusions present on the surface of the stud bolts. (author). 7 refs., 5 figs

  6. Flanged joints with contact outside the bolt circle: ASME Part B design rules

    International Nuclear Information System (INIS)

    The ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, gives rules which are subdivided into ''Part A'' and ''Part B''. Part A covers flanged joints where contact between flanges occurs through a gasket located inside the bolt holes. Part B covers flanged joints with contact outside the bolt holes. This report (a) summarizes the theory for Part B flanged joints, (b) presents examples which show the significant differences between Part A flanged joints and Part B flanged joints, (c) presents the available test data relevant to the characteristics of Part B flanged joints, (d) gives listings of two computer programs which can be used to evaluate the characteristics of Part B flanged joints, and (e) gives recommendations for Code revisions and other aspects of Part B flanged-joint design

  7. Contact Stress Analysis around Elliptical Bolt-loaded Hole in Orthotropic Plates

    Directory of Open Access Journals (Sweden)

    O. Aluko

    2012-12-01

    Full Text Available The practicality of changing the bolt shape from circular to elliptical under friction effects in order to reduce the contact stress distributions was analytically investigated. The analysis utilized the complex stress functions obtained from the assumed displacement expressions that satisfy the boundary conditions around the hole to determine the contact stresses. In the method of solution coulomb friction was used to determine the prescribed displacements at the boundary. The material properties of graphite/epoxy and carbon fiber reinforced plastics laminates were used in this investigation and the results compared with available literature. It was revealed that the stress distributions followed the same pattern in both geometries but with lower magnitude in elliptical shape and the reduction in stress distributions caused by changing the bolt shape from circular to elliptic depend on friction coefficient.

  8. Rock mass movements around development workings in various density of standing-and-roof-bolting support

    Institute of Scientific and Technical Information of China (English)

    MAJCHERCZYK Tadeusz; MALKOWSKLI Piotr; NIEDBALSKI Zbighiew

    2008-01-01

    Presented measurement results of roof rocks and wall rock movements of un-derground development workings after their drifting. The research was carried out in thecoal mine workings with standing-and-roof bolting support. There were various density ofthe support, so the aim of the special monitoring programme was to determine movementintensity of rock mass in the premises of the heading area. There were four types of re-search did by the authors. They measured convergence, roof layers separation using tell-tales and sonic probes and load bearing of the headings' roofs by hydraulic dynamometers.Evaluation of fracture zone around the heading and investigation the load zone caused byfailed roof rocks may become a basement for the determination of support parameters ofthe workings. The combined system of standing support and roof bolting seems to be anessential for underground headings protection.

  9. Mathematical representation of bolted-joint stiffness: A new suggested model

    International Nuclear Information System (INIS)

    Joint member stiffness in a bolted connection directly influences the safety of a design in regard to both static and fatigue loading, as well as in the prevention of separation in the connection. This work provides a new simple model for computing the member stiffness in bolted connections for both fully and partially developed stress envelope fields. The new model is built using a stress distribution polynomial of third order. Finite element analysis (FEA) is performed for some joints geometries, and the results are used to estimate the best analytical envelope angle in the proposed analytical model that gives suitable convergence between the compared results. An experimental effort is exerted to validate the accuracy of a suggested model. When analytical results are compared with FEA results and experimental data, the maximum absolute percentage errors are found to be 2.69 and 14.69, respectively. Also, a good agreement is obtained when the analytical results are compared with other researchers' results

  10. Experimental study on tunnel lining joints temporarily strengthened by SMA bolts

    International Nuclear Information System (INIS)

    Shield tunnels have been widely used in city metros all over the world. During the long-term period of the metro operation, the joints of shield tunnel’s neighboring segments may degrade due to some environmental factors, leading to the increasing of the joint opening and some resulting adverse consequences. In this paper, a temporary strengthening method by using shape memory alloy (SMA) bolts is proposed and experimentally studied for the joints of neighboring segments, and a revised electric heating method which suits with the strengthening method is presented and experimentally validated for the SMA bolts. The purpose of the proposed temporary strengthening method is to create favorable conditions for the following permanent strengthening. Test results show that: (a) for the joints of shield tunnel’s neighboring segments, the strengthening method can effectively reduce the joint opening, joint deflection, concrete strain in joint’s compression zone, and strain of joint’s steel bolts; (b) the revised electric heating method can be used to heat the SMA rod to a temperature higher than the SMA’s austenite finish temperature quickly, and the average heating rate related to Type 2 inner resistance element is larger than that related to Type 1 inner resistance element; and (c) the reduction percentages of the joint opening increment, joint deflection, concrete strain in joint’s compression zone, and strain of joint’s steel bolts for Specimen I are all larger than those for Specimen II, implying that the less the joint opening is, the more significant the strengthening effect is. (paper)

  11. Assessment of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest in veal calves.

    Science.gov (United States)

    Bartz, B; Collins, M; Stoddard, G; Appleton, A; Livingood, R; Sobcynski, H; Vogel, K D

    2015-09-01

    The purpose of this study was to evaluate the impact of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest on veal calf welfare, veal quality, and blood yield. Ninety calves from the same farm were randomly assigned to 1 of 2 treatment groups in a balanced unpaired comparison design. The first treatment group (the "head-only" method-application of the pneumatic nonpenetrating stun to the frontal plate of the skull at the intersection of 2 imaginary lines extending from the lateral canthus to the opposite poll [CONTROL]) was stunned with a nonpenetrating captive bolt gun ( = 45). The second group ( = 45) was stunned with a nonpenetrating captive bolt gun followed by secondary electrical induction of cardiac arrest (the "head/heart" method-initial application of the pneumatic nonpenetrating captive bolt stun followed by 1 s application of an electrical stun to the ventral region of the ribcage directly caudal to the junction of the humerus and scapula while the stunned calf was in lateral recumbence [HEAD/HEART]). Stunning efficacy was the indicator of animal welfare used in this study. All calves were instantly rendered insensible by the initial stun and did not display common indicators of return to consciousness. For meat quality evaluation, all samples were collected from the 12th rib region of the longissimus thoracis. Meat samples were evaluated for color, drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The L* values (measure of meat color lightness) were darker ( 0.05) observed in a* (redness) and b* (yellowness) values between treatments. No differences ( > 0.05) were observed in drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The blood yield from the CONTROL group (7,217.9 ± 143.5 g) was greater ( veal calves. PMID:26440354

  12. Variety Seeking, Purchase Timing, and the "Lightning Bolt" Brand Choice Model

    OpenAIRE

    Pradeep K. Chintagunta

    1999-01-01

    The "Lightning Bolt" (LB) model provides a comprehensive framework for accommodating the effects of habit persistence, unobserved heterogeneity, and state dependence on household brand choice behavior. This paper presents a discrete, dynamic brand-choice model that belongs to the LB class of models. We propose a method for incorporating the effects of variety seeking into the LB model formulation. The proposed formulation explicitly links brand choice and purchase timing behavior via the effe...

  13. Experimental Study on Mechanical Characteristics of Cracked Rock Mass Reinforced by Bolting and Grouting

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The stress hardening characteristics of the reinforced rock mass in uniaxial compression tests were revealed by means of the experimental study on mechanical characteristics of cracked rock mass reinforced by bolting and grouting. And the load-bearing mechanism of the reinforced rock mass was perfectly reflected by the experiment. The results can offer some useful advice for support design and stability analysis of deep drifts in unstable strata.

  14. Calculation of mechanical strength of the bolts of the flanged joints of LWR-type reactor pressure vessels (with particular emphasis on the behaviour under critical internal excess pressure, acting like a ''safety valve''). 5. Technical report

    International Nuclear Information System (INIS)

    The reactor pressure vessel has to be made absolutely fail-safe towards excess primary loads (internal pressure). For this purpose, the vessel is equipped with safety valves (e.g. at the pressurizer) which normally are fully sufficient to master any pressure excursion. Nevertheless, a deterministic safety approach requires additional measures to ensure, in case of safety valve failure, control of the pressure so as to prevent reactor pressure vessel bursting. One way to achieve this is to make the flange joints plastify so strongly in the course of a pressure transient that the flange gap will sufficiently widen and thus behave like a 'safety valve'. In order to keep damage as small as possible, these parts should be easy to replace so that the bolts, or rather the washers, seem to be appropriate for modification. Tests have been made to ascertain whether reduction of bolt cross-sectional area (increase in admissible stress), or insertion of suitable washers is the best way to achieve reliable behaviour under normal conditions and also additional function in terms of a safety valve in case of pressure transients. For this purpose, model calculations have been made for all possible flange joints whith all possible stress variations and bolt dimensions. The event simulated is the ATWS', and the strength computations and stress analyses made for the flange joints of the pressure vessel of the Biblis reactor, unit B, are taken as an example. Main attention has been given to the forces affecting the bolts and to the forces acting between the reactor vessel head flange and the vessel flange under internal excess pressure. For assessment of the thermodynamic processes in case of an ATWS, the calculations made for the Grafenrheinfeld reactor have been taken as a basis. (orig.)

  15. The loosing mechanism of screw bolts on the first wall graphite tiles in EAST

    International Nuclear Information System (INIS)

    The first wall in Experimental Advanced Superconducting Tokamak (EAST) has used many graphite tiles to face the plasma. All graphite ties have been mounted on heat sink using screw bolts which had been preloaded to produce clamp force. The clamp force is very important to keep the graphite tiles on the surface of the heat sink tightly because the heat flux will cross this contacting surface in a small thermal resistor. Without the clamp force the small gap between graphite tiles and heat sink will lead thermal power cannot be carried away by cooling water. The worse is some bolts turned out with the loss of clamp force. From the mathematical models the process of the loss of clamp force has been studied. Research results explain how the different thermal expansion of three members of the screw joint leads to the clamp force decrease to zero under temperature rise and external force and how the stiffness affect the relationship between the clamp force and temperature. The research also gets the critical temperature point that the clamp force can remain above zero. Research results indicated this screw joint is absolute to lose their clamp force during the EAST running so that the bolt joints should be redesign to improve its reliability.

  16. Preload Analysis of Screw Bolt Joints on the First Wall Graphite Tiles in EAST

    International Nuclear Information System (INIS)

    The first wall in the Experimental Advanced Superconducting Tokamak (EAST) used graphite tiles to withstand high thermal energy. The graphite tiles are mounted on the heat sink using screw bolts which have been preloaded to produce a clamp force. The clamp force is very important to keep the graphite tiles tightly on the surface of the heat sink so that the heat flux crosses this contacting surface in a small thermal resistor. Without the clamp force, the small gap between the graphite tiles and the heat sink will make it impossible for thermal power to be carried away by cooling water. Some bolts may even fall off with the loss of clamp force. From the mathematical models, the loss process of the clamp force has been studied. Research results explain how the different thermal expansions of three members of the screw joint makes the clamp force decrease to zero under temperature rise and external force, and how the stiffness affects the relation between the clamp force and temperature. The research also gives the critical temperature at which the clamp force can remain above zero. Analysis results indicate that the current screw joints are almost destined to lose their clamp force during the running time of EAST, so the bolt joints should be redesigned in order to improve its reliability.

  17. The loosing mechanism of screw bolts on the first wall graphite tiles in EAST

    Energy Technology Data Exchange (ETDEWEB)

    Lei Cao, E-mail: caolei@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Science, Shushanhu Road 350, Hefei 230031 (China); Song Yuntao; Zhou Zibo; Xu Weiwei [Institute of Plasma Physics, Chinese Academy of Science, Shushanhu Road 350, Hefei 230031 (China)

    2011-10-15

    The first wall in Experimental Advanced Superconducting Tokamak (EAST) has used many graphite tiles to face the plasma. All graphite ties have been mounted on heat sink using screw bolts which had been preloaded to produce clamp force. The clamp force is very important to keep the graphite tiles on the surface of the heat sink tightly because the heat flux will cross this contacting surface in a small thermal resistor. Without the clamp force the small gap between graphite tiles and heat sink will lead thermal power cannot be carried away by cooling water. The worse is some bolts turned out with the loss of clamp force. From the mathematical models the process of the loss of clamp force has been studied. Research results explain how the different thermal expansion of three members of the screw joint leads to the clamp force decrease to zero under temperature rise and external force and how the stiffness affect the relationship between the clamp force and temperature. The research also gets the critical temperature point that the clamp force can remain above zero. Research results indicated this screw joint is absolute to lose their clamp force during the EAST running so that the bolt joints should be redesign to improve its reliability.

  18. Characterization of tensile and shear loading on indented PC-strand cable bolts

    Institute of Scientific and Technical Information of China (English)

    Tadolini Stephen C.; ⇑; Derycke Steven; Bhagwat Anand

    2016-01-01

    The tensile and shear strength of intrinsic bolting support systems has always been a major concern of designers. A comprehensive laboratory testing program was designed to evaluate the tensile and shear strength of individual wires and completely wound PC-strand cables. PC-strand cables with smooth wires and the recent anchorage enhancement innovation of indentation were evaluated and compared. The testing protocol detailed in ISO Standard 15630 utilizes a mandrel system that was investigated at 3 different diameters which alters the wire to mandrel ratio from 2:1 to 9:1. The results demonstrate that the difference between smooth and indented wires is statistically insignificant when larger diameter mandrels are used, and that indentation does not adversely affect strand properties and performance. Insight into the shearing mechanism and evaluation techniques are discussed with the introduction of triaxial loading to describe the PC-strand tensile and shearing mechanisms. Another important result indicates that the shear strength of PC-strand cable bolting systems has a greater shear strength value than traditional steel bar bolting systems.

  19. Bolted join strength under parallel to grain double shear in guadua angustifolia structures

    Directory of Open Access Journals (Sweden)

    Fabián Augusto Lamus Báez

    2014-01-01

    Full Text Available In a bolted joint of structures that use Guadua angustifolia as the main supporting material, the resistance to the double metal shears paralleled to fiber could be influenced by an extensive list of parameters including parallel to fiber crushing resistance, parallel to metal fiber resistance of the wall and the contact area between elements in the joint. This paper presents experimental results for the resistance to the double metal shears paralleled to fiber, when the element is loaded under compression, for different culm diameters. Moreover, we studied the influence of the bolt diameter and culm thickness in the joint resistance. The tests were conducted on specimens of Guadua angustifolia with variable diameters between seven and fourteen centimeter where bolts of 3/8, 1/2 and 3/4" diameter were used. The Guadua tested came from the outskirts of Armenia in Colombia. It was found that the great amount of the double metal shears paralleled to fiber in the joint is provided by parallel to fiber crushing resistance of the Guadua.

  20. Holographic description of Kerr-Bolt-AdS-dS Spacetimes

    CERN Document Server

    Chen, B; Kamali, V; Setare, M R

    2010-01-01

    We show that there exists a holographic 2D CFT description of a Kerr-Bolt-AdS-dS spacetime. We first consider the wave equation of a massless scalar field propagating in extremal Kerr-Bolt-AdS-dS spacetimes and find in the "near region", the wave equation in extremal limit could be written in terms of the $SL(2,R)$ quadratic Casimir. This suggests that there exist dual CFT descriptions of these black holes. In the probe limit, we compute the scattering amplitudes of the scalar off the extremal black holes and find perfect agreement with the CFT prediction. Furthermore we study the holographic description of the generic four dimensional non-extremal Kerr-Bolt-AdS-dS black holes. We find that if focusing on the near-horizon region, for the massless scalar scattering in the low-frequency limit, the radial equation could still be rewritten as the $SL(2,R)$ quadratic Casimir, suggesting the existence of dual 2D description. We read the temperatures of the dual CFT from the conformal coordinates and obtain the cent...

  1. Holographic description of Kerr-Bolt-AdS-dS spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, B., E-mail: bchen01@pku.edu.c [Department of Physics, and State Key Laboratory of Nuclear Physics and Technology, and Center for High Energy Physics, Peking University, Beijing 100871 (China); Ghezelbash, A.M., E-mail: masoud.ghezelbash@usask.c [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada); Kamali, V., E-mail: vkamali1362@gmail.co [Department of Campus of Bijar, Kurdistan University, Bijar (Iran, Islamic Republic of); Setare, M.R., E-mail: rezakord@ipm.i [Department of Campus of Bijar, Kurdistan University, Bijar (Iran, Islamic Republic of)

    2011-07-01

    We show that there exists a holographic 2D CFT description of a Kerr-Bolt-AdS-dS spacetime. We first consider the wave equation of a massless scalar field propagating in extremal Kerr-Bolt-AdS-dS spacetimes and find in the 'near region', the wave equation in extremal limit could be written in terms of the SL(2,R) quadratic Casimir. This suggests that there exist dual CFT descriptions of these black holes. In the probe limit, we compute the scattering amplitudes of the scalar off the extremal black holes and find perfect agreement with the CFT prediction. Furthermore we study the holographic description of the generic four-dimensional non-extremal Kerr-Bolt-AdS-dS black holes. We find that if focusing on the near-horizon region, for the massless scalar scattering in the low-frequency limit, the radial equation could still be rewritten as the SL(2,R) quadratic Casimir, suggesting the existence of dual 2D description. We read the temperatures of the dual CFT from the conformal coordinates and obtain the central charges by studying the near-horizon geometry of near-extremal black holes. We recover the macroscopic entropy from the microscopic counting. We also show that for the super-radiant scattering, the retarded Green's functions and the corresponding absorption cross sections are in perfect match with CFT prediction.

  2. New Ultrasonic Optical Sealing Bolts for Dry Storage Containers

    OpenAIRE

    LITTMANN Francois; Sironi, Marco; SCHWALBACH Peter; MATLOCH Lukasz; WISHARD Bernie; KRAVTCHENKO Victor

    2015-01-01

    This paper presents a new seal for dry storage containers with nuclear material. Currently, sealing of dry storage casks containing spent fuel presents various challenges to safeguards inspectors. Continuity of knowledge needs to be reliably maintained over periods of time that can be decades. Seal replacements and verification , require significant Inspector efforts, radiological dose, and is continuing to grow. A decrease in Inspector effort is required and fail-safe redundancy is sought. T...

  3. A structural health monitoring fastener for tracking fatigue crack growth in bolted metallic joints

    Science.gov (United States)

    Rakow, Alexi Schroder

    Fatigue cracks initiating at fastener hole locations in metallic components are among the most common form of airframe damage. The fastener hole site has been surveyed as the second leading initiation site for fatigue related accidents of fixed wing aircraft. Current methods for inspecting airframes for these cracks are manual, whereby inspectors rely on non-destructive inspection equipment or hand-held probes to scan over areas of a structure. Use of this equipment often demands disassembly of the vehicle to search appropriate hole locations for cracks, which elevates the complexity and cost of these maintenance inspections. Improved reliability, safety, and reduced cost of such maintenance can be realized by the permanent integration of sensors with a structure to detect this damage. Such an integrated system of sensors would form a structural health monitoring (SHM) system. In this study, an Additive, Interleaved, Multi-layer Electromagnetic (AIME) sensor was developed and integrated with the shank of a fastener to form a SHM Fastener, a new SHM technology targeted at detection of fastener hole cracks. The major advantages of the SHM Fastener are its installation, which does not require joint layer disassembly, its capability to detect inner layer cracks, and its capability to operate in a continuous autonomous mode. Two methods for fabricating the proposed SHM Fastener were studied. The first option consisted of a thin flexible printed circuit film that was bonded around a thin metallic sleeve placed around the fastener shank. The second option consisted of coating sensor materials directly to the shank of a part in an effort to increase the durability of the sensor under severe loading conditions. Both analytical and numerical models were developed to characterize the capability of the sensors and provide a design tool for the sensor layout. A diagnostic technique for crack growth monitoring was developed to complete the SHM system, which consists of the

  4. 12 CFR 955.6 - Risk-based capital requirement for acquired member assets.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Risk-based capital requirement for acquired... ASSETS AND OFF-BALANCE SHEET ITEMS ACQUIRED MEMBER ASSETS § 955.6 Risk-based capital requirement for... times a factor associated with the putative credit rating of the assets or pools of assets as...

  5. 12 CFR 956.4 - Risk-based capital requirement for investments.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Risk-based capital requirement for investments... OFF-BALANCE SHEET ITEMS FEDERAL HOME LOAN BANK INVESTMENTS § 956.4 Risk-based capital requirement for... the investments multiplied by: (a) A factor associated with the credit rating of the investments...

  6. 42 CFR 488.68 - State Agency responsibilities for OASIS collection and data base requirements.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false State Agency responsibilities for OASIS collection and data base requirements. 488.68 Section 488.68 Public Health CENTERS FOR MEDICARE & MEDICAID... collection and data base requirements. As part of State agency survey responsibilities, the State agency...

  7. 煤矿锚杆支护技术现状与展望%On research status and prospect of mine bolt support technique and theory

    Institute of Scientific and Technical Information of China (English)

    朱雷; 周游

    2011-01-01

    The paper introduced the research status of mine bolt support technique and theory,summarized the design methods of bolt support and prospected the bolt support technique and theory.%介绍了锚杆技术及锚杆支护理论的研究现状,总结了锚杆支护的设计方法,提出了发展锚杆支护技术理论所需要开展的内容。

  8. Towards rule-based metabolic databases: a requirement analysis based on KEGG.

    Science.gov (United States)

    Richter, Stephan; Fetzer, Ingo; Thullner, Martin; Centler, Florian; Dittrich, Peter

    2015-01-01

    Knowledge of metabolic processes is collected in easily accessable online databases which are increasing rapidly in content and detail. Using these databases for the automatic construction of metabolic network models requires high accuracy and consistency. In this bipartite study we evaluate current accuracy and consistency problems using the KEGG database as a prominent example and propose design principles for dealing with such problems. In the first half, we present our computational approach for classifying inconsistencies and provide an overview of the classes of inconsistencies we identified. We detected inconsistencies both for database entries referring to substances and entries referring to reactions. In the second part, we present strategies to deal with the detected problem classes. We especially propose a rule-based database approach which allows for the inclusion of parameterised molecular species and parameterised reactions. Detailed case-studies and a comparison of explicit networks from KEGG with their anticipated rule-based representation underline the applicability and scalability of this approach. PMID:26547981

  9. Prediction of Software Requirements Stability Based on Complexity Point Measurement Using Multi-Criteria Fuzzy Approach

    Directory of Open Access Journals (Sweden)

    D. Francis Xavier Christopher

    2012-12-01

    Full Text Available Many software projects fail due to instable requirements and lack of managing the requirements changesefficiently. Software Requirements Stability Index Metric (RSI helps to evaluate the overall stability ofrequirements and also keep track of the project status. Higher the stability, less changes tends topropagate. The existing system use Function Point modeling for measuring the Requirements Stability.However, the main drawback of the existing modeling is that the complexity of non-functional requirementshas not been measured for Requirements Stability. The Non-Functional Factors plays a vital role inassessing the Requirements Stability. Numerous Measurement methods have been proposed for measuringthe software complexity. This paper proposes Multi-criteria Fuzzy Based approach for finding out thecomplexity weight based on Requirement Complexity Attributes such as Functional RequirementComplexity, Non-Functional Requirement Complexity, Input Output Complexity, Interface and FileComplexity. Based on the complexity weight, this paper computes the software complexity point. And thenpredict the Software Requirements Stability based on Software Complexity Point changes. The advantageof this model is that it is able to estimate the software complexity early which in turn predicts the SoftwareRequirement Stability during the software development life cycle.

  10. Handbook of methods for risk-based analysis of Technical Specification requirements

    International Nuclear Information System (INIS)

    Technical Specifications (TS) requirements for nuclear power plants define the Limiting Conditions for Operation (LCOs) and Surveillance Requirements (SRs) to assure safety during operation. In general, these requirements were based on deterministic analysis and engineering judgments. Experiences with plant operation indicate that some elements of the requirements are unnecessarily restrictive, while others may not be conducive to safety. Improvements in these requirements are facilitated by the availability of plant specific Probabilistic Safety Assessments (PSAs). The use of risk and reliability-based methods to improve TS requirements has gained wide interest because these methods can: quantitatively evaluate the risk impact and justify changes based on objective risk arguments. Provide a defensible basis for these requirements for regulatory applications. The United States Nuclear Regulatory Commission (USNRC) Office of Research is sponsoring research to develop systematic risk-based methods to improve various aspects of TS requirements. The handbook of methods, which is being prepared, summarizes such risk-based methods. The scope of the handbook includes reliability and risk-based methods for evaluating allowed outage times (AOTs), action statements requiring shutdown where shutdown risk may be substantial, surveillance test intervals (STIs), defenses against common-cause failures, managing plant configurations, and scheduling maintenances. For each topic, the handbook summarizes methods of analysis and data needs, outlines the insights to be gained, lists additional references, and presents examples of evaluations

  11. Operative hysteroscopy intravascular absorption syndrome: A bolt from the blue

    OpenAIRE

    Navdeep Sethi; Ravindra Chaturvedi; Krishna Kumar

    2012-01-01

    Operative hysteroscopy has emerged as an effective alternative to hysterectomy and has become standard surgical treatment for varied gynaecological conditions like abnormal uterine bleeding and uterine myomas. This procedure requires distention of the uterine cavity for adequate visualization of the operative field. 1.5% glycine is a widely used distention medium because it has good optical properties and is non-conductive. However, the intraoperative absorption of this electrolyte-free fluid...

  12. Development of rock bolt grout and shotcrete for rock support and corrosion of steel in low-pH cementitious materials

    Energy Technology Data Exchange (ETDEWEB)

    Boden, Anders (Vattenfall Power Consultant AB, Vaellingby (Sweden)); Pettersson, Stig (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden))

    2011-04-15

    It is foreseen that cementitious products will be utilized in the construction of the final repository. The use of conventional cementitious material creates pulses in the magnitude of pH 12.13 in the leachates and release alkalis. Such a high pH is detrimental mainly to impairment of bentonite functioning, but also to possibly enhanced dissolution of spent fuel and alteration of fracture filling materials. It also complicates the safety analysis of the repository, as the effect of a high pH-plume should be considered in the evaluation. As no reliable pH-plume models exist, the use of products giving a pH below 11 in the leachates facilitates the safety analysis, although limiting the amount of low-pH cement is recommended. In earlier studies it was found that shotcreting, standard casting and rock bolting with low-pH cement (pH . 11 in the leachate) should be possible without any major development work. This report summarizes the results of development work done during 2008 and 2009 in the fields of low-pH rock bolt grout, low-pH shotcrete and steel corrosion in low-pH concrete. Development of low-pH rock bolt grout mixes and laboratory testing of the selected grout was followed by installation of twenty rock bolts for rock support at Aspo HRL using the chosen low-pH grout. The operation was successful and the bolts and grout are subject to follow up the next ten years. Low-pH shotcrete for rock support was initially developed within the ESDRED project, which was an Integrated Project within the European Commission sixth framework for research and technological development. ESDRED is an abbreviation for Engineering Studies and Demonstrations of Repository Designs. ESDRED was executed from 1st February 2004 to 31st January 2009. The development of the mix design described in this report was based on the results from ESDRED. After laboratory testing of the chosen mix, it was field tested in niche NASA 0408A at Aspo HRL. Further, some areas in the TASS-tunnel were

  13. Development of rock bolt grout and shotcrete for rock support and corrosion of steel in low-pH cementitious materials

    International Nuclear Information System (INIS)

    It is foreseen that cementitious products will be utilized in the construction of the final repository. The use of conventional cementitious material creates pulses in the magnitude of pH 12.13 in the leachates and release alkalis. Such a high pH is detrimental mainly to impairment of bentonite functioning, but also to possibly enhanced dissolution of spent fuel and alteration of fracture filling materials. It also complicates the safety analysis of the repository, as the effect of a high pH-plume should be considered in the evaluation. As no reliable pH-plume models exist, the use of products giving a pH below 11 in the leachates facilitates the safety analysis, although limiting the amount of low-pH cement is recommended. In earlier studies it was found that shotcreting, standard casting and rock bolting with low-pH cement (pH . 11 in the leachate) should be possible without any major development work. This report summarizes the results of development work done during 2008 and 2009 in the fields of low-pH rock bolt grout, low-pH shotcrete and steel corrosion in low-pH concrete. Development of low-pH rock bolt grout mixes and laboratory testing of the selected grout was followed by installation of twenty rock bolts for rock support at Aspo HRL using the chosen low-pH grout. The operation was successful and the bolts and grout are subject to follow up the next ten years. Low-pH shotcrete for rock support was initially developed within the ESDRED project, which was an Integrated Project within the European Commission sixth framework for research and technological development. ESDRED is an abbreviation for Engineering Studies and Demonstrations of Repository Designs. ESDRED was executed from 1st February 2004 to 31st January 2009. The development of the mix design described in this report was based on the results from ESDRED. After laboratory testing of the chosen mix, it was field tested in niche NASA 0408A at Aspo HRL. Further, some areas in the TASS-tunnel were

  14. Identification of QTLs Related to Bolting in Brassica rapa ssp. pekinensis(syn. Brassica campestris ssp. pekinensis)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-wei; XIE Cong-hua; WANG Xiao-wu; WU Jian; ZHAO Jian-jun; SONG Xiao-fei; LI Ying; ZHANG Yan-guo; XU Dong-hui; SUN Ri-fei; YUAN Yu-xiang

    2006-01-01

    A genetic linkage map of Brassica rapa ssp. pekinensis was constructed with 186 AFLP (amplified fragment length polymorphism) markers by using a doubled-haploid (DH) population with 183 individuals. The individuals were derived from F1 which was developed by crossing a bolting resistant DH line Y-177-12 and an easy bolting DH line Y195-93a.AFLPs were generated by the use of restriction enzymes EcoR Ⅰ and Mse Ⅰ. The segregation of each marker and linkage was analyzed by using JoinMap version 3.0. Mapped markers were aligned in ten linkage groups which covered 887.8 cM with an average marker interval of 4.47 cM. Markers showing skewed segregation ratio were clustered in six LGs.Quantitative trait loci (QTL) were mapped for bolting resistance by using MAPQTL 4.0 package. Four QTLs explaining from 7.0 to 9.4% of the total variation were detected, all of them increase bolting resistance. These mapped QTLs could be used to develop a marker assisted selection programme for bolting resistance breeding.

  15. Testing of nuclear grade lubricants and their effects on A540 B24 and A193 B7 bolting materials

    International Nuclear Information System (INIS)

    An investigation was performed on eleven commonly used lubricants by the nuclear power industry. The investigation included EDS analysis of the lubricants, notched-tensile constant extension rate testing of bolting materials with the lubricants, frictional testing of the lubricants and weight loss testing of a bonded solid film lubricant. The report generally concludes that there is a significant amount of variance in the mechanical properties of common bolting materials; that MoS2 can hydrolyze to form H2S at 1000C and cause stress corrosion cracking (SCC) of bolting materials, and that the use of copper-containing lubricants can be potentially detrimental to high strength steels in an aqueous environment. Additionally, the testing of various lubricants disclosed that some lubricants contain potentially detrimental elements (e.g. S, Sb) which can promote SCC of the common bolting materials. One of the most significant findings of this report is the observation that both A193 B7 and A540 B24 bolting materials are susceptible to transgranular stress corrosion cracking in demineralized H2O at 2800C in notched tensile tests

  16. Key requirements of packet transport network based on MPLS-TP

    Science.gov (United States)

    Huang, Feng; Yi, Xiaobo; Zhang, Hanzheng; Gong, Ping

    2009-11-01

    Requirement of packet transport network based on MPLS-TP are analyzed including in transport plane, OAM, survivability, QoS, control plane and management plane. MPLS-TP standard status is also introduced.

  17. Course Ontology-Based User's Knowledge Requirement Acquisition from Behaviors within E-Learning Systems

    Science.gov (United States)

    Zeng, Qingtian; Zhao, Zhongying; Liang, Yongquan

    2009-01-01

    User's knowledge requirement acquisition and analysis are very important for a personalized or user-adaptive learning system. Two approaches to capture user's knowledge requirement about course content within an e-learning system are proposed and implemented in this paper. The first approach is based on the historical data accumulated by an…

  18. Transaction-based building controls framework, Volume 2: Platform descriptive model and requirements

    Energy Technology Data Exchange (ETDEWEB)

    Akyol, Bora A. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Haack, Jereme N. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Carpenter, Brandon J. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Katipamula, Srinivas [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Lutes, Robert G. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Hernandez, George [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

    2015-07-31

    Transaction-based Building Controls (TBC) offer a control systems platform that provides an agent execution environment that meets the growing requirements for security, resource utilization, and reliability. This report outlines the requirements for a platform to meet these needs and describes an illustrative/exemplary implementation.

  19. A New Classification Analysis of Customer Requirement Information Based on Quantitative Standardization for Product Configuration

    OpenAIRE

    Zheng Xiao; Zude Zhou; Buyun Sheng

    2016-01-01

    Traditional methods used for the classification of customer requirement information are typically based on specific indicators, hierarchical structures, and data formats and involve a qualitative analysis in terms of stationary patterns. Because these methods neither consider the scalability of classification results nor do they regard subsequent application to product configuration, their classification becomes an isolated operation. However, the transformation of customer requirement inform...

  20. A prescriptive approach to qualify and quantify customer value for value-based requirements engineering

    OpenAIRE

    Zhang, Xinwei; Auriol, Guillaume; Eres, Hakki; Baron, Claude

    2013-01-01

    Recently, customer-based product development is becoming a popular paradigm. Customer expectations and needs can be identified and transformed into requirements for product design with the help of various methods and tools. However, in many cases, these models fail to focus on the perceived value that is crucial when customers make the decision of purchasing a product. In this paper, a prescriptive approach to support value-based requirements engineering (RE) is proposed, describing the found...

  1. Traducción de elementos culturales en A man for all seasons, de Robert Bolt

    OpenAIRE

    Currás Móstoles, María Rosa

    2010-01-01

    Esta tesis doctoral se centra en el estudio del tratamiento de los referentes culturales en A Man for All Seasons, de Robert Bolt. Partiendo del hecho de que los textos literarios son productos de la cultura que los alojan, una obra literaria manifiesta su adscripción a dicha cultura por medio de ciertos elementos conocidos como referentes culturales. La importancia de los elementos culturales en traducción viene reforzada por la consideración de que los estudios de traducción actualmen...

  2. Tests and analysis of mechanical behaviours of rock bolt components for China's coal mine roadways

    OpenAIRE

    Hongpu Kang; Jinghe Yang; Xianzhi Meng

    2015-01-01

    A series of laboratory tests were performed to study the mechanical behaviours of newly developed high strength rock bolt components, including rebar, thread, plate, and domed washer. The characteristics of deformation and damage of each component were presented. The stress distribution of plate and domed washer was investigated through finite element modelling. The numerical results show that the yield and tensile strengths of the developed high strength rebar are 33.6%–58.3% and 17.2%–28.7%...

  3. The nuts and bolts of proofs an introduction to mathematical proofs

    CERN Document Server

    Cupillari, Antonella

    2005-01-01

    The Nuts and Bolts of Proof instructs students on the basic logic of mathematical proofs, showing how and why proofs of mathematical statements work. It provides them with techniques they can use to gain an inside view of the subject, reach other results, remember results more easily, or rederive them if the results are forgotten.A flow chart graphically demonstrates the basic steps in the construction of any proof and numerous examples illustrate the method and detail necessary to prove various kinds of theorems.* The "List of Symbols" has been extended.* Set Theory section has been strengthened with more examples and exercises.* Addition of "A Collection of Proofs"

  4. Investigations on bolts for reactor pressure vessels and connections of core internals

    International Nuclear Information System (INIS)

    As a material for studs with 300 mm diameter, 3,5 %-Ni steels were investigated experimentally with respect to their mechanical and fracture mechanical properties. The strength of the thread of large reactor vessel closure studs was determined by photoelastic tests on nut and bolt joints in tension and compression, by pressure tests on a scaled-down replica of the pressure vessel flange and on washers of AISI 4340, as well as thread stripping and fatigue tests on studs screwed into nuts. The specimens were made of the material normally used for the studs. (orig.)

  5. On the plastic behaviour of multi directional epoxy-bolted CFRP laminates

    DEFF Research Database (Denmark)

    Jensen, Aage; Poulsen, Ervin

    2004-01-01

    The second generation of CFRP laminate has recently been developed. It is a multi directional CFRP laminate, i.e. a laminate with carbon fibres having several directions other than the first generation. The paper describes the laboratory tests carried out in order to develop anchorage devices for...... such multi directional CFRP laminates which are epoxy-bonded and bolted or nailed to the concrete substrate for the purpose of strengthening against failure caused by bending. The tests were carried out at the Technical University of Denmark, IABM and Byg-DTU...

  6. The Nuts and Bolts of Proofs An Introduction to Mathematical Proofs

    CERN Document Server

    Cupillari, Antonella

    2011-01-01

    The Nuts and Bolts of Proofs instructs students on the primary basic logic of mathematical proofs, showing how proofs of mathematical statements work. The text provides basic core techniques of how to read and write proofs through examples. The basic mechanics of proofs are provided for a methodical approach in gaining an understanding of the fundamentals to help students reach different results. A variety of fundamental proofs demonstrate the basic steps in the construction of a proof and numerous examples illustrate the method and detail necessary to prove various kinds of theorems. Jumps r

  7. Upon bolting the GTR1 and GTR2 transporters mediate transport of glucosinolates to the inflorescence rather than roots

    DEFF Research Database (Denmark)

    Andersen, Tonni Grube; Halkier, Barbara Ann

    2014-01-01

    We recently described the glucosinolate transporters GTR1 and GTR2 as actively contributing to the establishment of tissue-specific distribution of the defense compounds glucosinolates in vegetative Arabidopsis plants. Upon bolting and thereby development of the inflorescence and initiation of seed...... setting, the spatial distribution of glucosinolates does undergo major changes. Here we investigate the role of GTR1 and GTR2 in establishment of glucosinolate source-sink relationships in bolting plants. By in vivo feeding the exogenous p-hydroxybenzylglucosinolate to a rosette leaf or the roots of...... wildtype and a gtr1 gtr2 mutant, we show that this glucosinolate can specifically translocate from the rosette and the roots to the inflorescence in a GTR1- and GTR2-dependent manner. This marks that, upon bolting, the inflorescence rather than the roots constitute the strongest sink for leaf...

  8. Use of the cylindrically guided wave technique for the inspection of stud bolts, valve stems and pump shafts

    International Nuclear Information System (INIS)

    Over the last several years, nuclear power plants have expressed concern about failures of bolting, valve stems, and pump shafts. This paper reports on the development of an ultrasonic technique to inspect these components. The authors have successfully demonstrated the cylindrically guided wave technique (CGWT) on a wide range of stud bolts. The CGWT employs zero-degree longitudinal waves constrained to travel within the boundary of the cylindrically shaped components during inspection. Theoretically explained, mode conversion occurs because the ultrasonic wave is guided down the length of the component. These mode-converted signals are dependent upon the diameter of the component under inspection and the longitudinal- and shear-wave velocities of the component material. This technique has also been successfully used on valve stems in the field. The geometry of the valve stem is very similar to that of the stud bolt

  9. 40 CFR 63.1283 - Inspection and monitoring requirements.

    Science.gov (United States)

    2010-07-01

    ...) of this section. (i) For each closed-vent system joints, seams, or other connections that are permanently or semi-permanently sealed (e.g., a welded joint between two sections of hard piping or a bolted... using air emission controls in accordance with the requirements of § 63.1275. (b) (c) Closed-vent...

  10. Texture analysis of Napoleonic War Era copper bolts

    Science.gov (United States)

    Malamud, Florencia; Northover, Shirley; James, Jon; Northover, Peter; Kelleher, Joe

    2016-04-01

    Neutron diffraction techniques are suitable for volume texture analyses due to high penetration of thermal neutrons in most materials. We have implemented a new data analysis methodology that employed the spatial resolution achievable by a time-of-flight neutron strain scanner to non-destructively determine the crystallographic texture at selected locations within a macroscopic sample. The method is based on defining the orientation distribution function of the crystallites from several incomplete pole figures, and it has been implemented on ENGIN-X, a neutron strain scanner at the Isis Facility in the UK. Here, we demonstrate the application of this new texture analysis methodology in determining the crystallographic texture at selected locations within museum quality archaeological objects up to 1 m in length. The results were verified using samples of similar, but less valuable, objects by comparing the results of applying this method with those obtained using both electron backscatter diffraction and X-ray diffraction on their cross sections.

  11. Development of ultrasonic testing technique for anchor bolts. Part 2. Development of nondestructive examination method for fatigue cracks by ultrasonic phased array technology

    International Nuclear Information System (INIS)

    Cracks may initiate in anchor bolts in nuclear power plants due to a severe earthquake. Moreover, number of fatigue cracks have been found in the anchor bolts in aged nuclear and thermal power plants. Ultrasonic phased array technology is effective to detect such cracks, and a method is proposed to determine crack depth by using refection echo at the vicinity of crack according to simulation results of wave propagation within bolts. However, detectability of crack and applicability of this method for crack sizing are not known though they are essential to evaluation of crack in bolts by ultrasonic phased array technology. In this report, we prepared M24 and M30 bolt specimens with various slits and fatigue cracks introduced. Three linear array probes with respective frequency of 2, 5 and 10 MHz are used to measure these specimens. The investigation of fracture surface is also performed after finishing all measurements. Measurement results show the following: (1) the frequency of 10 MHz is more appropriate than frequencies of 5 and 2 MHz for detecting crack in bolts; (2) it is easy to detect 1-mm-deep cracks; and (3) it is possible to determine crack depth for M30 bolts with the deviation of 2 mm from actual depth by proposed method, but difficult for M24 bolts. (author)

  12. Generic functional requirements for a NASA general-purpose data base management system

    Science.gov (United States)

    Lohman, G. M.

    1981-01-01

    Generic functional requirements for a general-purpose, multi-mission data base management system (DBMS) for application to remotely sensed scientific data bases are detailed. The motivation for utilizing DBMS technology in this environment is explained. The major requirements include: (1) a DBMS for scientific observational data; (2) a multi-mission capability; (3) user-friendly; (4) extensive and integrated information about data; (5) robust languages for defining data structures and formats; (6) scientific data types and structures; (7) flexible physical access mechanisms; (8) ways of representing spatial relationships; (9) a high level nonprocedural interactive query and data manipulation language; (10) data base maintenance utilities; (11) high rate input/output and large data volume storage; and adaptability to a distributed data base and/or data base machine configuration. Detailed functions are specified in a top-down hierarchic fashion. Implementation, performance, and support requirements are also given.

  13. FUZZY REQUIREMENT BASED STRATEGY OF QoS SERVICE FOR BROADBAND TELECOMMUNICATION NETWORKS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A fuzzy requirement based strategy for QoS service in broadband networks was presented. With the analysis of QoS service in ATM networks and broadband IP networks, it gave a requirement-based strategy for QoS service application with Fuzzy language evaluation principles. The requirement parameters are chosen according to the WANT/COST rule, and a fuzzy set is constructed to realize the fuzzy determinant. The simulation results show that it is useful to evaluate the QoS service in broadband networks, and to effectively simplify the access protocols and solve the billing issues in broadband networks.

  14. Definition of nearly zero-energy building requirements based on a large building sample

    International Nuclear Information System (INIS)

    According to the recast of the Energy Performance Building Directive, Member States must give an exact definition for nearly zero-energy buildings to be introduced from 2018/2020. The requirement system stipulating the sustainable development of the building sector is usually based on the analysis of a few reference buildings, combining energy efficiency measures and HVAC systems. The risk of this method is that depending on the assumptions either the requirements do not provide sufficient incentives for energy saving measures and renewables or the requirements cannot be fulfilled with rational solutions in many cases. Our method is based on the artificial generation of a large building sample, where the buildings are defined by geometric and other parameters. Due to the large number of combinations, the effect of many variables appear in the results, with the deviations reflecting the sensitivity of the energy balance. The requirements are set based on some fundamental considerations and the statistical analysis of the sample. The method is demonstrated on the example of setting the requirements for residential buildings in Hungary. The proposed requirements are validated against the common European targets. The suggested method is suitable for developing building energy regulation threshold values, certification schemes or benchmarking values. - Highlights: • We analyse the European nearly zero-energy building definition. • We present a method for setting requirements based on a large building sample. • We demonstrate the method for residential buildings in Hungary. • We compare the results with the European targets

  15. STATISTICAL ENTROPIES OF THE TAUB-NUT/BOLT AdS SPACES FROM THE HORIZON CONFORMAL FIELD THEORY

    Institute of Scientific and Technical Information of China (English)

    JING JI-LIANG; ZHOU SAN-QING; HUANG YI-BIN

    2001-01-01

    The covariant phase technique is used to compute the constraint algebra of the four-dimensional space-times which are asymptotic to anti-de Sitter (AdS), such as the planar Taub-NUT AdS and Taub-bolt AdS spaces, and the hyperbolic Taub-bolt AdS space. The standard Virasoro subalgebrae with corresponding central charges for these objects are constructed and the resulting densities of states yield the expected Bekenstein-Hawking entropies.

  16. Customer Requirements Mapping Method Based on Association Rule Mining for Mass Customization

    Institute of Scientific and Technical Information of China (English)

    XIA Shi-sheng; WANG Li-ya

    2008-01-01

    Customer requirements analysis is the key step for product variety design of mass customiza-tion(MC). Quality function deployment (QFD) is a widely used management technique for understanding thevoice of the customer (VOC), however, QFD depends heavily on human subject judgment during extractingcustomer requirements and determination of the importance weights of customer requirements. QFD pro-cess and related problems are so complicated that it is not easily used. In this paper, based on a generaldata structure of product family, generic bill of material (CBOM), association rules analysis was introducedto construct the classification mechanism between customer requirements and product architecture. The newmethod can map customer requirements to the items of product family architecture respectively, accomplishthe mapping process from customer domain to physical domain directly, and decrease mutual process betweencustomer and designer, improve the product design quality, and thus furthest satisfy customer needs. Finally,an example of customer requirements mapping of the elevator cabin was used to illustrate the proposed method.

  17. 12 CFR 702.103 - Applicability of risk-based net worth requirement.

    Science.gov (United States)

    2010-01-01

    ... AFFECTING CREDIT UNIONS PROMPT CORRECTIVE ACTION Net Worth Classification § 702.103 Applicability of risk... risk-based net worth requirement is applicable only if the credit union meets both of the following... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Applicability of risk-based net...

  18. Evaluation and decision of products conceptual design schemes based on customer requirements

    International Nuclear Information System (INIS)

    Within the competitive market environment, understanding customer requirements is crucial for all corporations to obtain market share and survive competition. Only the products exactly meeting customer requirements can win in the market place. Therefore, customer requirements play a very important role in the evaluation and decision process of conceptual design schemes of products. In this paper, an evaluation and decision method based on customer requirements is presented. It utilizes the importance of customer requirements, the satisfaction degree of each evaluation metric to the specification, and an evaluation metric which models customer requirements to evaluate the satisfaction degree of each design scheme to specific customer requirements via the proposed BP neural networks. In the evaluation and decision process, fuzzy sets are used to describe the importance of customer requirements, the relationship between customer requirements and evaluation metrics, the satisfaction degree of each scheme to customer requirements, and the crisp set is used to describe the satisfaction degree of each metric to specifications. The effectiveness of the proposed method is demonstrated by an example of front suspension fork design of mountain bikes

  19. The Extended Thermodynamic Properties of a topological Taub-NUT/Bolt-AdS spaces

    CERN Document Server

    Lee, Chong Oh

    2015-01-01

    We consider the extended thermodynamic quantities of higher dimensional topological Taub-NUT/Bolt-AdS black holes with a cosmological constant treated as a pressure and find their general form for arbitrary dimensions and the thermodynamics of these configurations is argued to some extent. In particular by introducing Gibbs free energy, it is found out to be a new thermodynamically stable region of these black holes. At an equilibrium condition we find an entropy of a NUT solution, volume, and latent heat are negative where the Clapeyron equation is satisfied for these thermodynamic quantities. These negative volume and entropy may be interpreted as that the environment applies work to the system in the process of the Taub-NUT-AdS black hole formation, and such negative latent heat may indicate a net release of latent energy back into the environment because of evaporating of the system. Intriguingly, we also find that like the AdS black hole case, Taub-Bolt-AdS black hole with two phases (phase of small and ...

  20. Professor Usain Bolt Welcomes You to the Schoolyard: Physics for Champions

    Science.gov (United States)

    Vourlias, Kostas; Seroglou, Fanny

    2016-01-01

    Could Usain Bolt achieve what teachers often fail to do? Could this famous Olympic winner challenge and motivate students to study mechanics and introduce them to the principles of physics in a fun way, outside of the classroom? In order to answer these questions, we "invited" for one semester the world record holder to visit our Greek high school in Thessaloniki as a guest teacher. For 13 weeks, 27 fifteen-year-olds run (or at least try to run) side by side with this great athlete, intending to learn his secrets. Within 9.58 s or 100 m, students have the chance to study a "phenomenon" of their daily lives and be introduced to a variety of concepts of physics in a pleasant and effective way. Students use simple athletic and innovative biomechanical equipment for their experiments, but mostly their own bodies, as experimental tools in order to study and to "feel" physics. Students have the chance to compare their athletic abilities to Bolt's and confront some of their ideas concerning concepts of physics.

  1. Entry roof truss-bolt system test under the gob of contiguous seams

    Institute of Scientific and Technical Information of China (English)

    LIAN Chuan-jie; XU Wei-ya; WANG Ya-jie

    2007-01-01

    Roof bolt support system has been widely applied in the No.7.9 seam in Caozhuang coal mine.However,it has not been able to be applied in the NO.10-2 seam since the small interburden(2m)between NO.9 and NO.10-2 seam.The NO.9 and NO.10-2 seams are contiguous seams.The NO.9 seam has been mined out and the NO.10-2 seam will be mined under the gob of the NO.9 seam.The roof strata of the NO.10-2 seam may have been weakened and fractured due to the shear failure caused by the NO.9 seam mining activities.The steel beam sets spaced at 0.8 m have been used to support the entry of the NO.10-2 seam.In order to speed up the advance rate and cut entry development cost,a test area,using roof bolt in conjunction with truss-system,was successfully conducted.This paper presents the support system design,application of designed system,and the test results.Test results provide a cheaper,quicker,and safer way to support entry for the No.10-2 seam.

  2. Experimental study of bolted connections using light gauge channel sections and packing plates at the joints

    Science.gov (United States)

    Kulkarni, Ravindra B.; Vaghe, Vishal M.

    2014-12-01

    Cold-formed structural members are being used more widely in routine structural design as the world steel industry moves from the production of hot-rolled section and plate to coil and strip, often with galvanized and/or painted coatings. Steel in this form is more easily delivered from the steel mill to the manufacturing plant where it is usually cold-rolled into open and closed section members. In the present experimental study, the use of packing plate at the joints in cold-formed channel sections may increase the load carrying capacity and also reduce the buckling of unconnected cold form channel steel plate at joints. The present study focuses on examining the experimental investigation to use mild steel as a packing plate with cold-formed channel sections by bolted connection at the joints and the connection subjected to axial tension. Series of tests are carried out with increase in the thickness of packing plate and results are observed and analyzed. Total Twelve experimental tests have been carried out on cold-formed channel tension members fastened with single as well as three numbers of bolts at the connection and from the observations the strength of the joint is increased by increasing the various thicknesses of packing plates and also the buckling of unconnected leg of channel specimen is reduced. It is analyzed by plotting the entire load versus elongation path, so that the behavior of the connection is examined.

  3. Design and demonstration of Bolt Retractor Separation system for X-38 Deorbit Propulsion Stage

    Science.gov (United States)

    Ahmed, R.; Johnston, A. S.; Garrison, J. C.; Gaines, J. L.; Waggoner, J. D.

    2003-09-01

    A separation system was designed for the X-38 experimental crew return vehicle program to allow the Deorbit Propulsion Stage (DPS) to separate from the X-38 lifting body during reentry operations. The configuration chosen was a spring-loaded plunger, known as the Bolt Retractor Subsystem (BRS), that retracts each of the six DPS-to-lifting body attachment bolts across the interface plane after being triggered by a separation nut mechanism. The system was designed to function on the ground in an atmospheric environment as well as in space. The BRS provides the same functionality as that of a completely pyrotechnic shear separation system that would normally be considered ideal for this application, but at a much lower cost. This system also could potentially be applied to future space station crew return vehicles. The design goal of 40 ms retraction time was successfully met in a series of demonstrations performed at the NASA Marshall Space Flight Center's Pyrotechnic Shock Facility (PSF) and Flight Robotics Laboratory (FRL). It must be emphasized that a full-scale test series was not performed on the BRS due to program schedule and cost constraints.

  4. Noise trauma induced by a mousetrap--sound pressure level measurement of vole captive bolt devices.

    Science.gov (United States)

    Frank, Matthias; Napp, Matthias; Lange, Joern; Grossjohann, Rico; Ekkernkamp, Axel; Beule, Achim G

    2010-05-01

    While ballistic parameters of vole captive bolt devices have been reported, there is no investigation on their hazardous potential to cause noise trauma. The aim of this experimental study was to measure the sound pressure levels of vole captive bolt devices. Two different shooting devices were examined with a modular precision sound level meter on an outdoor firing range. Measurements were taken in a semi-circular configuration with measuring points 0 degrees in front of the muzzle, 90 degrees at right angle of the muzzle, and 180 degrees behind the shooting device. Distances between muzzle and microphone were 0.5, 1, 2, 10, and 20 m. Sound pressure levels exceeded 130 dB(C) at any measuring point within the 20-m area. Highest measurements (more than 172 dB[C]) were taken in the 0 degrees direction at the 0.5-m distance for both shooting devices proving the hazardous potential of these gadgets to cause noise trauma. PMID:20345785

  5. A dynamic access control method based on QoS requirement

    Science.gov (United States)

    Li, Chunquan; Wang, Yanwei; Yang, Baoye; Hu, Chunyang

    2013-03-01

    A dynamic access control method is put forward to ensure the security of the sharing service in Cloud Manufacturing, according to the application characteristics of cloud manufacturing collaborative task. The role-based access control (RBAC) model is extended according to the characteristics of cloud manufacturing in this method. The constraints are considered, which are from QoS requirement of the task context to access control, based on the traditional static authorization. The fuzzy policy rules are established about the weighted interval value of permissions. The access control authorities of executable service by users are dynamically adjusted through the fuzzy reasoning based on the QoS requirement of task. The main elements of the model are described. The fuzzy reasoning algorithm of weighted interval value based QoS requirement is studied. An effective method is provided to resolve the access control of cloud manufacturing.

  6. RiskREP: Risk-Based Security Requirements Elicitation and Prioritization

    OpenAIRE

    Herrmann, Andrea; Morali, Ayse; Etalle, Sandro; Wieringa, Roel

    2011-01-01

    Companies are under pressure to be in control of their assets but at the same time they must operate as efficiently as possible. This means that they aim to implement “good-enough security” but need to be able to justify their security investment plans. In this paper, we present a Risk-Based Requirements Prioritization method (RiskREP) that extends misuse case-based methods with IT architecture based risk assessment and countermeasure definition and prioritization. Countermeasure prioritizati...

  7. Security Measurement Based On GQM To Improve Application Security During Requirements Stage

    Directory of Open Access Journals (Sweden)

    Ala A. Abdulrazeg

    2015-05-01

    Full Text Available Developing secure web applications that can withstand malicious attacks requires a careful injection of security considerations into early stages of development lifecycle. Assessing security at the requirement analysis stage of the application development life cycle may help in mitigating security defects before they spread their wings into the latter stages of the development life cycle and into the final version of product. In this paper, we present a security metrics model based on the Goal Question Metric (GQM approach, focusing on the design of the misuse case model. Misuse case is a technique to identify threats and integrate security requirements during the requirement analysis stage. The security metrics model helps in discovering and evaluating the misuse case models by ensuring a defect-free model. Here, the security metrics are based on the OWASP top 10-2010, in addition to misuse case modeling antipattern.

  8. Modeling of Car-Following Required Safe Distance Based on Molecular Dynamics

    OpenAIRE

    Dayi Qu; Xiufeng Chen; Wansan Yang; Xiaohua Bian

    2014-01-01

    In car-following procedure, some distances are reserved between the vehicles, through which drivers can avoid collisions with vehicles before and after them in the same lane and keep a reasonable clearance with lateral vehicles. This paper investigates characters of vehicle operating safety in car following state based on required safe distance. To tackle this problem, we probe into required safe distance and car-following model using molecular dynamics, covering longitudinal and lateral safe...

  9. Evaluation of a new arterial pressure-based cardiac output device requiring no external calibration

    OpenAIRE

    Amann Matthias; Trabold Benedikt; Schweiger Stefan; Keyl Cornelius; Bele Sylvia; Prasser Christopher; Welnhofer Julia; Wiesenack Christoph

    2007-01-01

    Abstract Background Several techniques have been discussed as alternatives to the intermittent bolus thermodilution cardiac output (COPAC) measurement by the pulmonary artery catheter (PAC). However, these techniques usually require a central venous line, an additional catheter, or a special calibration procedure. A new arterial pressure-based cardiac output (COAP) device (FloTrac™, Vigileo™; Edwards Lifesciences, Irvine, CA, USA) only requires access to the radial or femoral artery using a s...

  10. Equilibrium theory-based design of simulated moving bed processes under reduced purity requirements linear isotherms.

    Science.gov (United States)

    Rajendran, Arvind

    2008-03-28

    The design of simulated moving bed processes under reduced purity requirements for systems whose isotherm is linear is considered. Based on the equilibrium theory of chromatography, explicit equations to uniquely identify the separation region that will ensure specified extract and raffinate purities are derived. The identification of the region requires only the knowledge of Henry constants of the solutes, the concentration of the solutes in the feed and the purity specifications. These results are validated using numerical simulations. PMID:18281052

  11. Security Measurement Based On GQM To Improve Application Security During Requirements Stage

    OpenAIRE

    Ala A. Abdulrazeg; Norita Md Norwawi; Nurlida Basir

    2015-01-01

    Developing secure web applications that can withstand malicious attacks requires a careful injection of security considerations into early stages of development lifecycle. Assessing security at the requirement analysis stage of the application development life cycle may help in mitigating security defects before they spread their wings into the latter stages of the development life cycle and into the final version of product. In this paper, we present a security metrics model based on the Goa...

  12. Precision requirements for space-based X(CO2) data

    International Nuclear Information System (INIS)

    Precision requirements are determined for space-based column-averaged CO2 dry air mole fraction X(CO2) data. These requirements result from an assessment of spatial and temporal gradients in X(CO2), the relationship between X(CO2) precision and surface CO2 flux uncertainties inferred from inversions of the X(CO2) data, and the effects of X(CO2) biases on the fidelity of CO2 flux inversions. Observational system simulation experiments and synthesis inversion modeling demonstrate that the Orbiting Carbon Observatory mission design and sampling strategy provide the means to achieve these X(CO2) data precision requirements. (authors)

  13. A Methodology to Evaluate Object oriented Software Systems Using Change Requirement Traceability Based on Impact Analysis

    Directory of Open Access Journals (Sweden)

    Sunil T. D

    2014-06-01

    Full Text Available It is a well known fact that software maintenance plays a major role and finds importance in software development life cycle. As object - oriented programming has become the standard, it is very important to understand the problems of maintaining object -oriented software systems. This paper aims at evaluating object - oriented software system through change requirement traceability – based impact analysis methodology for non functional requirements using functional requirements . The major issues have been related to change impact algorithms and inheritance of functionality.

  14. User requirements for NASA data base management systems. Part 1: Oceanographic discipline

    Science.gov (United States)

    Fujimoto, B.

    1981-01-01

    Generic oceanographic user requirements were collected and analyzed for use in developing a general multipurpose data base management system for future missions of the Office of Space and Terrestrial Applications (OSTA) of NASA. The collection of user requirements involved; studying the state-of-the-art technology in data base management systems; analyzing the results of related studies; formulating a viable and diverse list of scientists to be interviewed; developing a presentation format and materials; and interviewing oceanographic data users. More effective data management systems are needed to handle the increasing influx of data.

  15. Fundamental study on pull-out strength of cast-in-place anchor bolt in concrete subjected to high temperature

    International Nuclear Information System (INIS)

    Some recent research on high temperature behavior of concrete shows that its strength will decrease with further increase of temperature, and other mechanical properties also get worse, due to drying shrinkage, thermal stress and so on. Cast-in place anchor bolts are used in many structural applications. There is possibility that these anchor bolts will be exposed to high temperature in a short time by some accident, and that the pull-out strength will decrease. This paper describes a study on the pull-out strength of a cast-in-place anchor bolt installed in concrete which is subjected to high temperatures up to 500degC to obtain basic experimental data and to examine the response of cast-in-place anchor bolts to high temperature exposure. Tests results show that the pull-out strength under high temperature decreases significantly. The pull-out strength during heating and after heating up to 500degC was 20% and 50% of it in normal temperature, respectively. (author)

  16. The characteristics of head wounds inflicted by "humane killer" (captive-bolt gun)--a 15-year study.

    Science.gov (United States)

    Simic, Milan; Draskovic, Dragan; Stojiljkovic, Goran; Vukovic, Radenko; Budimlija, Zoran M

    2007-09-01

    The "humane killer" or captive-bolt gun, is the tool/weapon widely used in meat industry and private farmer households for slaughtering animal stock. Out of 17,250 autopsies performed at the Institute of Forensic Medicine in Novi Sad during the 15-year period (1991-2005), 29 cases of suicides and two homicides were committed by captive-bolt pistols. Wounds inflicted by captive-bolt guns have specific morphological features, distinctive from wounds made by other kinds of hand firearms. Selected features of the captive-bolt wounds (punched round entrance and a double pattern of smoke soiling) depend on distance and angle of instrument at the time of firing. Autopsy findings were compared with an experimental model consisting of 20 domestic pigs. Obtained results confirmed that the appearance of the entrance hole and soot deposits, along with differences in shape, location, extent, and density of soot blackening, could be useful in identification of weapon, direction of discharge, shooting distance, and angle of the muzzle to the frontal and sagittal planes of the head at the moment of fire. PMID:17767661

  17. Inflatable rock bolt bond strength versus rock mass rating (RMR):A comparative analysis of pull-out testing data from underground mines in Nevada

    Institute of Scientific and Technical Information of China (English)

    Barnard Chase; Kallu Raj R.; Warren Sean; Thareja Rahul

    2016-01-01

    The purpose of this paper is to establish confidence in anticipated minimum bond strength for inflatable rock bolts by comparing the bond strength to variable geotechnical conditions using the rock mass rating (RMR) system. To investigate a correlation between these parameters, the minimum bond strength of pull-out tested inflatable rock bolts was compared to the RMR of the rock in which these bolts were placed. Bond strength vs. RMR plots indicate that expected minimum bond strength is positively corre-lated with RMR;however, the correlation is not strong. Cumulative percent graphs indicate that 97%of pull-out tests result in a minimum bond strength of 3.3 and 1.7 ton/m in RMR P 45 and<45, respectively. Although lower bond strengths are more commonly encountered in low RMR ground, high bond strengths are possible as well, yielding higher variability in bond strengths in low RMR ground. Bond strength of friction bolts relies on contact between the rock bolt and drill hole. Experience in Nevada indicates that RMR is known to affect both the quality and consistency of drill holes which likely affects bond strength. Drilling and bolting in low RMR ground is more sensitive to drilling and bolting practices, and strategies for maximizing bond strength in these conditions are discussed.

  18. System Requirements Analysis for a Computer-based Procedure in a Research Reactor Facility

    International Nuclear Information System (INIS)

    This can address many of the routine problems related to human error in the use of conventional, hard-copy operating procedures. An operating supporting system is also required in a research reactor. A well-made CBP can address the staffing issues of a research reactor and reduce the human errors by minimizing the operator's routine tasks. A CBP for a research reactor has not been proposed yet. Also, CBPs developed for nuclear power plants have powerful and various technical functions to cover complicated plant operation situations. However, many of the functions may not be required for a research reactor. Thus, it is not reasonable to apply the CBP to a research reactor directly. Also, customizing of the CBP is not cost-effective. Therefore, a compact CBP should be developed for a research reactor. This paper introduces high level requirements derived by the system requirements analysis activity as the first stage of system implementation. Operation support tools are under consideration for application to research reactors. In particular, as a full digitalization of the main control room, application of a computer-based procedure system has been required as a part of man-machine interface system because it makes an impact on the operating staffing and human errors of a research reactor. To establish computer-based system requirements for a research reactor, this paper addressed international standards and previous practices on nuclear plants

  19. SMEs Credit Risk Modelling for Internal Rating Based Approach in Banking Implementation of Basel II Requirement

    OpenAIRE

    Lin, Shu-Min

    2007-01-01

    This thesis explores the modelling for Internal Rating Based (IRB) of Credit Risk for Small and Medium Enterprises (SMEs) as required for implementation of Basel II Accord. There has been limited previous research for this important sector of the economy. There are two major approaches: Accounting Based and Merton Type, and these are compared. To make the comparison initially a small sample is considered and simulation is used to explore the use of the two approaches. The st...

  20. 12 CFR Appendix C to Part 567 - Risk-Based Capital Requirements-Internal-Ratings-Based and Advanced Measurement Approaches

    Science.gov (United States)

    2010-01-01

    ... CFR part 225, appendix G, to calculate its risk-based capital requirements. (2) Any savings..., Restructuring, and Improvement Act and under 12 CFR 567.1 (definition of “qualifying residential construction... association's underlying business risk factors and internal control environment. Carrying value means,...

  1. Enabling Requirements-Based Programming for Highly-Dependable Complex Parallel and Distributed Systems

    Science.gov (United States)

    Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.

    2005-01-01

    The manual application of formal methods in system specification has produced successes, but in the end, despite any claims and assertions by practitioners, there is no provable relationship between a manually derived system specification or formal model and the customer's original requirements. Complex parallel and distributed system present the worst case implications for today s dearth of viable approaches for achieving system dependability. No avenue other than formal methods constitutes a serious contender for resolving the problem, and so recognition of requirements-based programming has come at a critical juncture. We describe a new, NASA-developed automated requirement-based programming method that can be applied to certain classes of systems, including complex parallel and distributed systems, to achieve a high degree of dependability.

  2. Experimental development based on mapping rule between requirements analysis model and web framework specific design model.

    Science.gov (United States)

    Okuda, Hirotaka; Ogata, Shinpei; Matsuura, Saeko

    2013-12-01

    Model Driven Development is a promising approach to develop high quality software systems. We have proposed a method of model-driven requirements analysis using Unified Modeling Language (UML). The main feature of our method is to automatically generate a Web user interface prototype from UML requirements analysis model so that we can confirm validity of input/output data for each page and page transition on the system by directly operating the prototype. We proposes a mapping rule in which design information independent of each web application framework implementation is defined based on the requirements analysis model, so as to improve the traceability to the final product from the valid requirements analysis model. This paper discusses the result of applying our method to the development of a Group Work Support System that is currently running in our department. PMID:23565356

  3. xmlTRAM +:an XML-based tool for management of requirements and architectures

    Institute of Scientific and Technical Information of China (English)

    吴洁; 丁秋林

    2004-01-01

    Information systems have been increasingly used in all aspects of organization's business activities. These systems will inevitably evolve over time. The system development knowledge is a key to the understanding and evolution of these systems. As such, the system development knowledge is a part of the corporate knowledge that needs to be properly managed. In particular, the system requirements and architecture design are the most important system development knowledge. An XML-based tool for managing system requirements and architectures is introduced. The use of the XML technology allows the system requirements and architectures to be easily shared across the organization. The issues discussed include a conceptual model, a logical model and a physical model for the management of system requirements and architectures. In fact, this three-step development process provides a typical methodology for the development of XMLbased systems.

  4. Psychotherapy Training for Residents: Reconciling Requirements with Evidence-Based, Competency-Focused Practice

    Science.gov (United States)

    Weerasekera, Priyanthy; Manring, John; Lynn, David John

    2010-01-01

    Objective: The Accreditation Council for Graduate Medical Education (ACGME) and the Royal College of Physicians and Surgeons of Canada (RCPSC) changed the training requirements in psychotherapy, moving toward evidence-based therapies and emphasizing competence and proficiency as outcomes of training. This article examines whether the therapies…

  5. Scenario-based Requirements Elicitation in a Pain-teletreatment Application

    NARCIS (Netherlands)

    Widya, I.; Bults, R.G.A.; Huis in 't Veld, M.H.A.; Vollenbroek-Hutten, M.M.R.; Shishkov, B.B.; Cordeiro, J.; Ranchordas, A.

    2009-01-01

    This paper proposes a way to elicit requirements in the domain of eHealth, in particular telemedicine treatment, that is in alignment with the evidence based working practice in medicine. In collaboration with ICT developers, medical professionals co-shape the intended system, which has to support t

  6. Engineering Requirements for Offshore CO₂ Transportation and Storage: A Summary Based on International Experiences

    OpenAIRE

    Haszeldine, R. Stuart; Zhou, Di; Zhang, Yunfang

    2014-01-01

    To date there is no full-chain CCUS project involving offshore storage in China. This report gives a general review on major engi- neering requirements and their relevance and justification for offshore CO2 transportation and storage based on international experiences. The capital costs are mentioned briefly. The geological and system integration issues are expected to be covered in other reports.

  7. RiskREP: Risk-Based Security Requirements Elicitation and Prioritization

    NARCIS (Netherlands)

    Herrmann, Andrea; Morali, Ayse; Etalle, Sandro; Wieringa, Roel

    2011-01-01

    Companies are under pressure to be in control of their assets but at the same time they must operate as efficiently as possible. This means that they aim to implement “good-enough security” but need to be able to justify their security investment plans. In this paper, we present a Risk-Based Require

  8. Development of NRC requirements for standby diesel generators based on recent operating experience

    International Nuclear Information System (INIS)

    NRC's regulatory requirements pertaining to emergency diesel generators will continue to evolve. The need for enhanced maintenance and surveillance programs has clearly been identified. The reliance upon qualification testing and periodic surveillance testing has been retained but the test frequencies and conditions have been reduced to minimize the potential for creating new problems. An analysis of the requirements imposed by the Japanese and the resulting reliability levels achieved by them indicates that the NRC requirements appear to be headed in the right direction. The Japanese require EDGs to be routinely tested every two (2) weeks but do not require these to be fast/cold starts. A fast start is only performed at each refueling onstage. Between refuelings they do not change the frequency of surveillance tests based on the number of past failures and they do not require additional special tests when either an EDG or an offsite power circuit is lost. In addition, each EDG is completely overhauled and inspected every two (2) years. These requirements have resulted in almost failure free diesel operation at their nuclear plants

  9. Standardized Procedure Content And Data Structure Based On Human Factors Requirements For Computer-Based Procedures

    International Nuclear Information System (INIS)

    Most activities that involve human interaction with systems in a nuclear power plant are guided by procedures. Traditionally, the use of procedures has been a paper-based process that supports safe operation of the nuclear power industry. However, the nuclear industry is constantly trying to find ways to decrease the human error rate, especially the human errors associated with procedure use. Advances in digital technology make computer-based procedures (CBPs) a valid option that provides further enhancement of safety by improving human performance related to procedure use. The transition from paper-based procedures (PBPs) to CBPs creates a need for a computer-based procedure system (CBPS). A CBPS needs to have the ability to perform logical operations in order to adjust to the inputs received from either users or real time data from plant status databases. Without the ability for logical operations the procedure is just an electronic copy of the paper-based procedure. In order to provide the CBPS with the information it needs to display the procedure steps to the user, special care is needed in the format used to deliver all data and instructions to create the steps. The procedure should be broken down into basic elements and formatted in a standard method for the CBPS. One way to build the underlying data architecture is to use an Extensible Markup Language (XML) schema, which utilizes basic elements to build each step in the smart procedure. The attributes of each step will determine the type of functionality that the system will generate for that step. The CBPS will provide the context for the step to deliver referential information, request a decision, or accept input from the user. The XML schema needs to provide all data necessary for the system to accurately perform each step without the need for the procedure writer to reprogram the CBPS. The research team at the Idaho National Laboratory has developed a prototype CBPS for field workers as well as the

  10. Standardized Procedure Content And Data Structure Based On Human Factors Requirements For Computer-Based Procedures

    Energy Technology Data Exchange (ETDEWEB)

    Bly, Aaron; Oxstrand, Johanna; Le Blanc, Katya L

    2015-02-01

    Most activities that involve human interaction with systems in a nuclear power plant are guided by procedures. Traditionally, the use of procedures has been a paper-based process that supports safe operation of the nuclear power industry. However, the nuclear industry is constantly trying to find ways to decrease the human error rate, especially the human errors associated with procedure use. Advances in digital technology make computer-based procedures (CBPs) a valid option that provides further enhancement of safety by improving human performance related to procedure use. The transition from paper-based procedures (PBPs) to CBPs creates a need for a computer-based procedure system (CBPS). A CBPS needs to have the ability to perform logical operations in order to adjust to the inputs received from either users or real time data from plant status databases. Without the ability for logical operations the procedure is just an electronic copy of the paper-based procedure. In order to provide the CBPS with the information it needs to display the procedure steps to the user, special care is needed in the format used to deliver all data and instructions to create the steps. The procedure should be broken down into basic elements and formatted in a standard method for the CBPS. One way to build the underlying data architecture is to use an Extensible Markup Language (XML) schema, which utilizes basic elements to build each step in the smart procedure. The attributes of each step will determine the type of functionality that the system will generate for that step. The CBPS will provide the context for the step to deliver referential information, request a decision, or accept input from the user. The XML schema needs to provide all data necessary for the system to accurately perform each step without the need for the procedure writer to reprogram the CBPS. The research team at the Idaho National Laboratory has developed a prototype CBPS for field workers as well as the

  11. Failure analysis of bolted joints in foam-core sandwich composites

    DEFF Research Database (Denmark)

    Zabihpoor, M.; Moslemian, Ramin; Afshin, M.;

    2008-01-01

    This study represents an effort to predict the bearing strength, failure modes, and failure load of bolted joints in foam-core sandwich composites. The studied joints have been used in a light full composite airplane. By using solid laminates, a new design for the joint zone is developed. These...... using 3D FEM in ANSYS commercial code. Tsai-Wu failure criterion is used in the failure analysis. The results indicate that the most important parameter in the proposed joint zone design is the foam -solid laminate interface angle which plays an important role on the value of failure criterion (damage...... analysis, the increase of solid laminate size or interface angle could result in considerable higher buckling strength....

  12. Diagnosis of a captive-bolt injury in a skull extremely destroyed by fire.

    Science.gov (United States)

    Bohnert, Michael; Schmidt, Ulrike; Perdekamp, Markus Grosse; Pollak, Stefan

    2002-07-17

    The authors report on a combined suicide of a 71-year-old farmer who fired a shot to his forehead with a livestock stunner before burning himself. As the fire was fueled by a pile of firewood it burnt for many hours, thus, causing subtotal incineration of the body. The remaining bones were calcined and reduced to a residual mass of only 3 kg. In spite of the extreme destruction, a circular bone defect corresponding to the site where the captive-bolt had entered the skull could be identified in the frontal squama. The example of this suicide is used to illustrate the problems of distinguishing between mechanical and thermal fractures. As expected, the attempted isolation and amplification of both nuclear and mitochondrial DNA for the purpose of identification was not successful. PMID:12175948

  13. INFORMATION FOR USERS OF NUTS, BOLTS, SCREWS, NAILS AND RIVETS (SCEM GROUP 47)

    CERN Multimedia

    Logistics Group

    2002-01-01

    We should like to remind users that, since the closure of the self-service stores, nuts, bolts, screws, nails and rivets (Group 47 of the Stores Catalogue) can be obtained, in smaller packages than via EDH, from the 'Emergency Counter' in the Central Stores (Building 73, R-002) upon presentation of a duly completed hard-copy Materials Request form. The 'Emergency Counter' is open Mondays to Fridays from 7.30 a.m. to 11.50 a.m. and from 1.00 p.m. to 4.20 p.m. Information concerning the available packages can be found under the appropriate SCEM reference number in the Stores Catalogue. Logistics Group SPL Division

  14. Numerical study of rock bolting parameter variation effect on stability of stratified, composite roof structure of drift in a coal mine

    Institute of Scientific and Technical Information of China (English)

    LU Ting-kan; LIU Yu-zhou

    2005-01-01

    Described the outcomes of a comprehensive numerical modeling on the rock bolting performance for preventing the deformation of stratified, composite roof structure of drift in a coal mine. The investigation was undertaken in the adverse geological conditions, with variation of belt parameters, including length, density, distribution, pretension,as well as the geometry of opening, so as to determine the effect of bolting parameter variation on roof deformation and stability. The outcomes clearly demonstrated that a significant improvement of roof stability can be achieved associating with bolting parameters optimization, and indicated the importance of flexible geotechnical designation of rock mbolting reinforcement in mining practice.

  15. STUDY THE IMPACT OF REQUIREMENTS MANAGEMENT CHARACTERISTICS IN GLOBAL SOFTWARE DEVELOPMENT PROJECTS: AN ONTOLOGY BASED APPROACH

    Directory of Open Access Journals (Sweden)

    S. Arun Kumar

    2011-11-01

    Full Text Available Requirements Management is one of the challenging and key tasks in the development of software productsin distributed software development environment. One of the key reasons found in our literature survey thefailure of software projects due to poor project management and requirement management activity. Thismain aim of this paper 1. Formulate a framework for the successful and efficient requirements managementframework for Global Software Development Projects. (GSD 2. Design a Mixed organization structure ofboth traditional approaches and agile approaches, of global software development projects. 3. ApplyOntology based Knowledge Management Systems for both the approaches to achieve requirements issuessuch as missing, inconsistency of requirements, communication and knowledge management issues andimprove the project management activities in a global software development environment. 4. Proposerequirements management metrics to measure and manage software process during the development ofinformation systems. The major contribution of this paper is to analyze the requirements managementissues and challenges associated with global software development projects. Two hypotheses have beenformulated and tested this problem through statistical techniques like correlation and regression analysisand validate the same.

  16. Evaluating requirements on the Spitzer Mission operations system based on flight operations experience

    Science.gov (United States)

    Sarrel, Marc A.; Hunt, Joseph C., Jr.

    2008-07-01

    The Spitzer Space Telescope launched in August 2003, and has been in its nominal operations phase since December 2003. This paper will review some of the pre-launch, high-level project requirements in light of our operations experience. We discuss how we addressed some of those requirements pre-launch, what post-launch development we've done based on our experience, and some recommendations for future missions. Some of the requirements we examine in this paper are related to observational efficiency, completeness of data return, on-board storage of science data, and response time for targets of opportunity and data accountability. We also discuss the bearing that mission constraints have had on our solutions. These constraints include Spitzer's heliocentric orbit and resulting declining telecom performance, CPU utilization, relatively high data rate for a deep space mission, and use of both on-board RF power amplifiers, among others.

  17. The space exploration initiative. Operational efficiency panel space-basing technology requirements

    Science.gov (United States)

    Pena, Luis R.

    1991-01-01

    The topics covered include the following: (1) space basing technology requirements sources; (2) orbit transfer vehicle (OTV) processing heritage; (3) ground processing progression to space processing; (4) technology requirements for space based OTV servicing and maintenance; (5) design and development schedule for OTV's and OTV accommodations/ support hardware; (6) cryogenic technology test program development; (7) cryogenic propellant transfer, storage, and reliquefaction management summary; (8) propellant transfer technology analysis and ground testing; (8) OTV propellant storage depot development critical scaling relationships; (9) flight experiment options; (10) OTV maintenance; (11) automated fault detection/ isolation and system checkout summary; (12) engine replacement; (13) alternative docking operation; (14) OTV/payload integration; and (15) technology criticality and capability assessment. This document is presented in viewgraph form.

  18. Research on Marketing Cooperation System Based on Multi-Agent Services Aggregation Driven by Requirement

    Directory of Open Access Journals (Sweden)

    Hong ZHOU

    2010-11-01

    Full Text Available The web service has great significance and value since it represents a large industrial sector and huge trade interests, but the function of a single web service is too small to satisfy the need of service requestor, so it is necessary to combine a mount of simple services to satisfy the complex and dynamic requirement in practice, then the problem of web services composition is one of the research hotspot. This paper generalized the primary interaction processes between enterprise and customer in marketing, encapsulated the special function for marketing works as the agent, and considered the marketing as the cooperation process of agents focusing on requirements, and based on that a multi-agent based marketing cooperation system (MAMCS is established and the agent ontology is designed according to JADE, finally the negotiation mechanism is built. The method of multi-agent services aggregation driven by requirement supposed in this paper can improve the utilizing effect of service, reduce the difficulty of services composition, and realize the automatic purpose of services composition. Moreover, by combining the merits of agent technique the initiation and intelligence of the services are improved, that safeguard the best interests of the service providers due to they have an option on requirements.

  19. Reference evapotranspiration estimates based on minimum meteorological variable requirements of historical weather data

    OpenAIRE

    Antonio J. Steidle Neto; João C. F. Borges Júnior; Camilo L.T Andrade; Daniela C Lopes; Priscilla T Nascimento

    2015-01-01

    Reference evapotranspiration (ET0) is critical for agricultural and urban planning, irrigation scheduling, regional water balance studies, and agroclimatological zoning. The objective of this study was to estimate ET0 based on methods with minimum meteorological variable requirements and on empirical models to predict solar radiation. These alternative methods were compared to the FAO Penman-Monteith method by using more than 80 yr of historical weather data. Alternative methods were adapted ...

  20. Microcomputer-based detachment administrative management system for the LAMPS community: a requirements analysis

    OpenAIRE

    Smith, Gregory F.

    1985-01-01

    This thesis presents a requirements analysis of a micro-computer based system to be used by sea-going Light Airborne Multi-purpose System (LAMPS) detachment for administrative data management and recurring reports generation. Included are the results of user interviews which were conducted to determine possible system functions. These functions, through analysis, are presented in a hierarchical charting with data flow diagrams and accompanying processing narratives. System data is then presen...

  1. National Aeronautics and Space Administration Manned Spacecraft Center data base requirements study

    Science.gov (United States)

    1971-01-01

    A study was conducted to evaluate the types of data that the Manned Spacecraft Center (MSC) should automate in order to make available essential management and technical information to support MSC's various functions and missions. In addition, the software and hardware capabilities to best handle the storage and retrieval of this data were analyzed. Based on the results of this study, recommendations are presented for a unified data base that provides a cost effective solution to MSC's data automation requirements. The recommendations are projected through a time frame that includes the earth orbit space station.

  2. Mechanical properties of fasteners -- Part 7: Torsional test and minimum torques for bolts and screws with nominal diameters 1 mm to 10 mm

    CERN Document Server

    International Organization for Standardization. Geneva

    1992-01-01

    Applies to bolts and screws of property classes 8.8 to 12.9 in accordance with ISO 898-1 with thread less than M3 for which no breaking and proof loads are indicated in ISO 898-1, as well as to short bolts and screws with nominal diameters 3 mm to 10 mm which cannot be subjected to a tensile test. The minimum breaking torques are not valid for hexagon socket set screws.

  3. Fatigue Property of Open-Hole Steel Plates Influenced by Bolted Clamp-up and Hole Fabrication Methods

    Directory of Open Access Journals (Sweden)

    Zhi-Yu Wang

    2016-08-01

    Full Text Available Steel plates with open holes are commonly used in structural assemblies. The fatigue properties of such details are influenced by bolted clamp-up and hole fabrication methods. The fracture surface, stiffness degradation and fatigue life of test specimens are investigated in detail and compared with the contemporary test data. The analysis results show that the presence of draglines greatly influences the fatigue crack initiation at the open-hole cut by laser. The bolted clamp-up condition greatly enhances the stiffness and the fatigue life of the open-hole details. A discussion is also made from a comparison with the referred fatigue life of hole fabrication details, such as the influence of plate thickness and plasma cutting, drilling and oxy-fuel gas cutting, with the details studied herein. This work could enhance the understanding of the fatigue property and design of such details.

  4. Cortisol Hormone Concentration and Meat Quality of Beef Cattle Stunned by Captive Bolt Stun Gun before Slaughtering

    OpenAIRE

    K. Maghfiroh; H. Latif; K. Santoso

    2014-01-01

    This study was aimed to describe cortisol hormone concentration and meat quality which were produced in beef cattle stunned with captive bolt stun gun before slaughtering. Blood and meat samples were taken from Brahman cross steers (n= 11) in two abattoirs located in West Java and Banten. Blood samples were collected immediately after slaughtering. Cortisol hormone concentration in the serum was measured by using radioimmunoassay (RIA). The descriptive, correlation, and regression analyses we...

  5. Ultrasonic Detection of Small Crack in Studs[Bolts] by Time Difference of Thread Signals(TDTS)

    International Nuclear Information System (INIS)

    It is difficult to detect such flaws as stress - corrosion cracking or corrosion wastage(loss of bolt diameter) in the threads. In many cases the critical size of a flaw is very small(1-2 mm order). This paper describes how it is possible to discriminate small flaw indications in threads using the time difference or thread signals(TDTS) by a signal-conditioning technique

  6. The effects of electrical stunning and percussive captive bolt stunning on meat quality of cattle processed by Turkish slaughter procedures.

    Science.gov (United States)

    Onenç, A; Kaya, A

    2004-04-01

    The effects of electrical and percussive captive bolt stunning both on initial and up to 14 days post mortem meat quality of Friesian young bulls were studied. The first group (NS; n=10) were slaughtered without stunning under Turkish slaughter procedure (these animals were slaughtered under conditions acceptable to the appropriate ethics committee) in a modern abattoir. In the second group (ES; n=10) animals were electrically stunned. In the third group (PS; n=10) animals were stunned with percussive captive bolt. Meat quality was assessed by examining muscle glycogen concentration, pH and WHC. Also cooking loss, texture parameters and consumer sensory properties were assessed at 24 h, 4, 7 and 14 days post mortem. Meat colour as L(∗), a(∗), b(∗), C(∗), h(∗) values were evaluated at 0, 48 h, 3, 5, 7, 9 and 14 days post mortem. Pre-slaughter handling affected muscle glycogen concentration (P<0.05). Animals in electrical and percussive captive bolt stunned groups had higher muscle glycogen concentrations compared to animals in the non-stunned group (P<0.05). Although pre-slaughter handling did not affect significantly pH(24 h) and WHC, differences were significant for cooking loss, colour coordinates and texture parameters at some storage times. For all sensory attributes (odour, flavour, tenderness and overall acceptability) at all ageing periods (24 h, 4, 7 and 14 days) the percussive stunned (PS) group was significantly superior to the non-stunned (NS) group. The electrically-stunned (ES) group also tended to be superior to the NS group although not all differences were statistically significant. These results indicate that percussive captive bolt stunning of cattle improved meat quality compared with cattle electrically stunned using head only tongs and those non stunned under approved Turkish slaughter procedure. PMID:22061012

  7. Requirements and Challenges of Location-Based Access Control in Healthcare Emergency Response

    DEFF Research Database (Denmark)

    Vicente, Carmen Ruiz; Kirkpatrick, Michael; Ghinita, Gabriel;

    2009-01-01

    Recent advances in positioning and tracking technologies have led to the emergence of novel location-based applications that allow participants to access information relevant to their spatio-temporal context. Traditional access control models, such as role-based access control (RBAC), are not...... complex access control decisions based on spatio-temporal relationships among subjects and objects. Furthermore, such relationships change frequently in dynamic environments, requiring efficient mechanisms to monitor and re-evaluate access control decisions. In this position paper, we present a healthcare...... emergency response scenario which highlights the novel challenges that arise when enforcing access control in an environment with moving subjects and objects. To address a realistic application scenario, we consider movement on road networks, and we identify complex access control decisions relevant to such...

  8. Sequence-Length Requirement of Distance-Based Phylogeny Reconstruction: Breaking the Polynomial Barrier

    CERN Document Server

    Roch, Sebastien

    2009-01-01

    We introduce a new distance-based phylogeny reconstruction technique which provably achieves, at sufficiently short branch lengths, a polylogarithmic sequence-length requirement -- improving significantly over previous polynomial bounds for distance-based methods. The technique is based on an averaging procedure that implicitly reconstructs ancestral sequences. In the same token, we extend previous results on phase transitions in phylogeny reconstruction to general time-reversible models. More precisely, we show that in the so-called Kesten-Stigum zone (roughly, a region of the parameter space where ancestral sequences are well approximated by ``linear combinations'' of the observed sequences) sequences of length $\\poly(\\log n)$ suffice for reconstruction when branch lengths are discretized. Here $n$ is the number of extant species. Our results challenge, to some extent, the conventional wisdom that estimates of evolutionary distances alone carry significantly less information about phylogenies than full sequ...

  9. Requirements for a systems-based research and development management process in transport infrastructure engineering

    Directory of Open Access Journals (Sweden)

    Rust, Frederik Christoffel

    2015-05-01

    Full Text Available The management of research and development (R&D in the transport infrastructure field is complex due to the multidisciplinary nature of the work. The literature shows that linear R&D models that progress from idea through to consumer product are not suitable for the management of such multi-disciplinary projects. This study focuses on determining the key characteristics required for a systems-based approach to the management of R&D projects. The information and data was compiled from literature reviews, interviews, and an e-mail survey with responses from 42 significant international R&D programmes. The findings confirmed the need for a systems-based approach to R&D management. The study formulated twelve principles or tenets for a new, systems-based approach.

  10. Minimum area requirements for an at-risk butterfly based on movement and demography.

    Science.gov (United States)

    Brown, Leone M; Crone, Elizabeth E

    2016-02-01

    Determining the minimum area required to sustain populations has a long history in theoretical and conservation biology. Correlative approaches are often used to estimate minimum area requirements (MARs) based on relationships between area and the population size required for persistence or between species' traits and distribution patterns across landscapes. Mechanistic approaches to estimating MAR facilitate prediction across space and time but are few. We used a mechanistic MAR model to determine the critical minimum patch size (CMP) for the Baltimore checkerspot butterfly (Euphydryas phaeton), a locally abundant species in decline along its southern range, and sister to several federally listed species. Our CMP is based on principles of diffusion, where individuals in smaller patches encounter edges and leave with higher probability than those in larger patches, potentially before reproducing. We estimated a CMP for the Baltimore checkerspot of 0.7-1.5 ha, in accordance with trait-based MAR estimates. The diffusion rate on which we based this CMP was broadly similar when estimated at the landscape scale (comparing flight path vs. capture-mark-recapture data), and the estimated population growth rate was consistent with observed site trends. Our mechanistic approach to estimating MAR is appropriate for species whose movement follows a correlated random walk and may be useful where landscape-scale distributions are difficult to assess, but demographic and movement data are obtainable from a single site or the literature. Just as simple estimates of lambda are often used to assess population viability, the principles of diffusion and CMP could provide a starting place for estimating MAR for conservation. PMID:26174312

  11. Improved Traceability of Mission Concept to Requirements Using Model Based Systems Engineering

    Science.gov (United States)

    Reil, Robin

    2014-01-01

    Model Based Systems Engineering (MBSE) has recently been gaining significant support as a means to improve the traditional document-based systems engineering (DBSE) approach to engineering complex systems. In the spacecraft design domain, there are many perceived and propose benefits of an MBSE approach, but little analysis has been presented to determine the tangible benefits of such an approach (e.g. time and cost saved, increased product quality). This thesis presents direct examples of how developing a small satellite system model can improve traceability of the mission concept to its requirements. A comparison of the processes and approaches for MBSE and DBSE is made using the NASA Ames Research Center SporeSat CubeSat mission as a case study. A model of the SporeSat mission is built using the Systems Modeling Language standard and No Magics MagicDraw modeling tool. The model incorporates mission concept and requirement information from the missions original DBSE design efforts. Active dependency relationships are modeled to analyze the completeness and consistency of the requirements to the mission concept. Overall experience and methodology are presented for both the MBSE and original DBSE design efforts of SporeSat.

  12. Improved Traceability of a Small Satellite Mission Concept to Requirements Using Model Based System Engineering

    Science.gov (United States)

    Reil, Robin L.

    2014-01-01

    Model Based Systems Engineering (MBSE) has recently been gaining significant support as a means to improve the "traditional" document-based systems engineering (DBSE) approach to engineering complex systems. In the spacecraft design domain, there are many perceived and propose benefits of an MBSE approach, but little analysis has been presented to determine the tangible benefits of such an approach (e.g. time and cost saved, increased product quality). This paper presents direct examples of how developing a small satellite system model can improve traceability of the mission concept to its requirements. A comparison of the processes and approaches for MBSE and DBSE is made using the NASA Ames Research Center SporeSat CubeSat mission as a case study. A model of the SporeSat mission is built using the Systems Modeling Language standard and No Magic's MagicDraw modeling tool. The model incorporates mission concept and requirement information from the mission's original DBSE design efforts. Active dependency relationships are modeled to demonstrate the completeness and consistency of the requirements to the mission concept. Anecdotal information and process-duration metrics are presented for both the MBSE and original DBSE design efforts of SporeSat.

  13. Study design requirements for RNA sequencing-based breast cancer diagnostics.

    Science.gov (United States)

    Mer, Arvind Singh; Klevebring, Daniel; Grönberg, Henrik; Rantalainen, Mattias

    2016-01-01

    Sequencing-based molecular characterization of tumors provides information required for individualized cancer treatment. There are well-defined molecular subtypes of breast cancer that provide improved prognostication compared to routine biomarkers. However, molecular subtyping is not yet implemented in routine breast cancer care. Clinical translation is dependent on subtype prediction models providing high sensitivity and specificity. In this study we evaluate sample size and RNA-sequencing read requirements for breast cancer subtyping to facilitate rational design of translational studies. We applied subsampling to ascertain the effect of training sample size and the number of RNA sequencing reads on classification accuracy of molecular subtype and routine biomarker prediction models (unsupervised and supervised). Subtype classification accuracy improved with increasing sample size up to N = 750 (accuracy = 0.93), although with a modest improvement beyond N = 350 (accuracy = 0.92). Prediction of routine biomarkers achieved accuracy of 0.94 (ER) and 0.92 (Her2) at N = 200. Subtype classification improved with RNA-sequencing library size up to 5 million reads. Development of molecular subtyping models for cancer diagnostics requires well-designed studies. Sample size and the number of RNA sequencing reads directly influence accuracy of molecular subtyping. Results in this study provide key information for rational design of translational studies aiming to bring sequencing-based diagnostics to the clinic. PMID:26830453

  14. Capital requirements for the transportaton of energy materials based on 1978 ARC estimates

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-01

    TERA's estimates of capital requirements to transport natural gas, crude oil, petroleum products, and coal in the US by 1990 are presented. Summaries of transportation investment requirements through 1990 are tabulated for Scenarios B, C, and D. Scenario A is high supply, high demand. Scenario B is a high energy demand, low oil and gas supply case and requires most capital for transportation of all energy commodities. Scenario D requires the least amount of investment in transportation and is the opposite in terms of supply-demand pressure represented by Scenario B. Scenario D is a high oil and gas supply, low energy demand scenario. Scenario C lies predictably in the middle representing a medium case for both supply and demand. Scenario C shows the highest level of investment for oil pipelines from the other scenarios, due to a supply demand balance favoring petroleum consumption. This second report covers chapters on natural gas, crude oil, petroleum products, and coal. The 1985 estimates given are based on an interpolation of the 1990 results from the 1978 year of reference.

  15. QoS Requirement Generation and Algorithm Selection for Composite Service Based on Reference Vector

    Institute of Scientific and Technical Information of China (English)

    Bang-Yu Wu; Chi-Hung Chi; Shi-Jie Xu; Ming Gu; Jia-Guang Sun

    2009-01-01

    Under SOA (Service-Oriented Architecture), composite service is formed by aggregating multiple component services together in a given workflow. One key criterion of this research topic is QoS composition. Most work on service composition mainly focuses on the algorithms about how to compose services according to assumed QoS, without considering where the required QoS comes from and the selection of user preferred composition algorithm among those with different computational cost and different selection results. In this paper, we propose to strengthen current service composition mechanism by generation of QoS requirement and its algorithm selection based on the QoS reference vectors which are calculated optimally from the existing individual services' QoS by registry to represent QoS overview about the best QoS,the worst (or most economical) QoS, or the average QoS of all composite services. To implement QoS requirement, which is determined according to QoS overview, this paper introduces two selection algorithms as two kinds of experiment examples,one aiming at the most accurate service selection and the other chasing for trade-off between selection cost and result.Experimental results show our mechanism can help the requester achieve his expected composite service with appropriate QoS requirement and customized selection algorithm.

  16. SEMANTIC WEB-BASED SOFTWARE ENGINEERING BY AUTOMATED REQUIREMENTS ONTOLOGY GENERATION IN SOA

    Directory of Open Access Journals (Sweden)

    Vahid Rastgoo

    2014-04-01

    Full Text Available This paper presents an approach for automated generation of requirements ontology using UML diagrams in service-oriented architecture (SOA. The goal of this paper is to convenience progress of software engineering processes like software design, software reuse, service discovering and etc. The proposed method is based on a four conceptual layers. The first layer includes requirements achieved by stakeholders, the second one designs service-oriented diagrams from the data in first layer and extracts XMI codes of them. The third layer includes requirement ontology and protocol ontology to describe behavior of services and relationships between them semantically. Finally the forth layer makes standard the concepts exists in ontologies of previous layer. The generated ontology exceeds absolute domain ontology because it considers the behavior of services moreover the hierarchical relationship of them. Experimental results conducted on a set of UML4Soa diagrams in different scopes demonstrate the improvement of the proposed approach from different points of view such as: completeness of requirements ontology, automatic generation and considering SOA.

  17. Dependencies among Architectural Views Got from Software Requirements Based on a Formal Model

    Directory of Open Access Journals (Sweden)

    Osis Janis

    2014-12-01

    Full Text Available A system architect has software requirements and some unspecified knowledge about a problem domain (e.g., an enterprise as source information for assessment and evaluation of possible solutions and getting the target point, a preliminary software design. The solving factor is architect’s experience and expertise in the problem domain (“AS-IS”. A proposed approach is dedicated to assist a system architect in making an appropriate decision on the solution (“TO-BE”. It is based on a formal mathematical model, Topological Functioning Model (TFM. Compliant TFMs can be transformed into software architectural views. The paper demonstrates and discusses tracing dependency links from the requirements to and between the architectural views.

  18. Modeling and verifying Web services driven by requirements: An ontology-based approach

    Institute of Scientific and Technical Information of China (English)

    HOU Lishan; JIN ZHi; WU Budan

    2006-01-01

    Automatic discovery and composition of Web services is an important research area in Web service technology, in which the specification of Web services is a key issue. This paper presents a Web service capability description framework based on the environment ontology. This framework depicts Web services capability in two aspects:the operable environment and the environment changes resulting from behaviors of the Web service. On the basis of the framework, a requirement-driven Web service composition model has been constructed. This paper brings forward the formalization of Web service interactions with π calculus. And an automatic mechanism converting conceptual capability description to the formal process expression has been built. This kind of formal specification assists in verifying whether the composite Web service model matches the requirement.

  19. Ergonomic requirements on computer-based information- and handling engineering in nuclear power plants

    International Nuclear Information System (INIS)

    This project provides regulatory authorities with a set of criteria for evaluating hybrid man-machine interfaces in nuclear power plant control rooms from a human factors point of view. Such standards are necessary for two reasons: (1) More and more computerised information and control systems have been and will be introduced in nuclear power plant control rooms. One possible result of this trend will be the creation of hybrid man machine interfaces which will provide both conventional and computer-based display and control devices. (2) Available rules and regulations do not contain detailed requirements on how to integrate both types of interface in such a way that plant operation by means of hybrid interfaces will be performed at least as reliably and safely as by means of conventional ones. To fill this gap, criteria and methods were developed which support practical checks of requirements to be applied to hybrid control rooms. This approach is based on state of the art methods and criteria in ergonomics. It makes it possible to analyse and to describe personnel's actions in a consistent and structured way in order to provide the information which is necessary for evaluating human reliability of task performance. Reliability can be evaluated with respect to - accuracy of required information on displays, - networking of tasks, - possibilities of interrupting and cancelling measures which have already been initiated, - possibility to carry out required manuel actions, - level of mental work-strain, - workload level, - probability of erroneous actions. This method is part of a catalogue of recommendations for evaluating hybrid nuclear power plant control rooms. The catalogue also contains recommendations for the design of computerised parts of the man-machine-interface. Application of these design recommendations will help create favourable conditions for an acceptable level of work-strain and for reliable task performance. (orig.)

  20. Historical controls for phase II surgically based trials requiring gross total resection of glioblastoma multiforme.

    Science.gov (United States)

    Butowski, Nicholas; Lamborn, Kathleen R; Berger, Mitchel S; Prados, Michael D; Chang, Susan M

    2007-10-01

    New treatments for patients with glioblastoma multiforme (GBM) are frequently tested in phase II surgically based clinical trials that require gross total resection (GTR). In order to determine efficacy in such single-arm phase II clinical trials, the results are often compared to those from a historical control group that is not limited to patients with GTR. Recursive partitioning analysis (RPA) can define risk groups within historical control groups; however, RPA analyses to date included patients irrespective of whether a patient had a GTR or not. To provide a more appropriate historical control group for surgically based trials requiring a GTR, we sought to determine survival for a group of patients with newly diagnosed GBM, all of who underwent GTR and were treated on prospective clinical trials. GTR was defined as removal of >90% of the enhancing mass, determined by postoperative magnetic resonance imaging. Of 893 patients with GBM treated during these trials, 153 underwent GTR. The median survival for the GTR group was 71 weeks (95% CI 65-76) which was better than those who did not have a GTR. Within the GTR group, the median age was 54 years (range 25-77 years), and median Karnofsky Performance Score was 90 (range 60-100). Considering only patients with GTR, age at diagnosis continued to be a statistically significant prognostic factor. Patients treated during surgically based phase II studies should be matched with a historical control group restricted to patients with similar pretreatment variables, including GTR. PMID:17457513

  1. ENVIRONMENTAL RISK ASSESSMENT OF SOME COPPER BASED FUNGICIDES ACCORDING TO THE REQUIREMENTS OF GOOD LABORATORY PRACTICE

    Directory of Open Access Journals (Sweden)

    Marga GRĂDILĂ

    2015-10-01

    Full Text Available The paper presents data demonstrating the functionality of biological systems reconstituted with aquatic organisms developed under Good Laboratory Practice testing facility within Research - Development Institute for Plant Protection Bucharest for environmental risk assessment of four fungicides based on copper, according to Good Laboratory Practice requirements. For risk assessment, according to GLP were made the following steps: Good Laboratory Practice test facility was established, we have ensured adequate space for growth, acclimatization and testing for each test species, it was installed a complex water production instalation needed to perform tests, it was achieved control system for checking environmental conditions and have developed specific operating procedures that have been accredited according to Good Laboratory Practice.The results showed that biological systems model of the Good Laboratory Practice test facility in Research - Development Institute for Plant Protection meet the requirements of Organisation for Economic Co-operation and Development Guidelines regarding GLP, and after testing copper-based fungicides in terms of acute toxicity Cyprinus carpio and to Daphnia magna revealed that three of them (copper oxychloride, copper hydroxide and copper sulphate showed ecological efficiency, ie low toxicity. Metallic copper based fungicides showed a higher toxicity, resulting in fish toxicity symptoms: sleep, sudden immersion, faded, weakness, swimming in spiral, lack of balance, breathing slow and cumbersome, spasms and mortality.

  2. A conceptual model to empower software requirements conflict detection and resolution with rule-based reasoning

    Science.gov (United States)

    Ahmad, Sabrina; Jalil, Intan Ermahani A.; Ahmad, Sharifah Sakinah Syed

    2016-08-01

    It is seldom technical issues which impede the process of eliciting software requirements. The involvement of multiple stakeholders usually leads to conflicts and therefore the need of conflict detection and resolution effort is crucial. This paper presents a conceptual model to further improve current efforts. Hence, this paper forwards an improved conceptual model to assist the conflict detection and resolution effort which extends the model ability and improves overall performance. The significant of the new model is to empower the automation of conflicts detection and its severity level with rule-based reasoning.

  3. Inquiry-Based Laboratory Activity to Investigate Physical Growth Requirements of Microorganisms

    Directory of Open Access Journals (Sweden)

    Michelle Furlong

    2014-08-01

    Full Text Available Standard "cookbook" laboratory activities that are used to teach students the optimal physical growth conditions of microorganisms should be modified so that they more effectively foster student's higher order cognitive skills and attract student interest.  This paper describes a laboratory activity that engages students in an inquiry-based approach to studying the physical growth requirements of microorganisms.  In this activity, students design and implement an experiment to obtain pure cultures of specific microorganisms, with distinct growth properties, that are provided to them in a mixed culture.

  4. Technical requirements on knowledge base and instrumentation system for decision making in plant operation and maintenance

    International Nuclear Information System (INIS)

    A series of technical surveys and studies are described in this report to examine and identify technical requirements to be posed on knowledge base and instrumentation system as the fundamental in high reliability computational decision making in operation and maintenance of nuclear power plants. Monitoring and diagnosis are focused as the important tasks among the operation/maintenance-related tasks. A concrete monitoring and diagnosis system configuration has been proposed consisting of distributed symptom database and of on-demand measurement subsystem. An prototype of the proposed system configuration has been successfully verified. (author)

  5. Contribution to the design of bolted angle connection in the steel structures

    Directory of Open Access Journals (Sweden)

    Veličković Dragan S.

    2004-01-01

    Full Text Available The paper presents the equations for the determination of the neutral axis position, when it is on the face, that is, on the bearing plate, and for the highest normal tensile stress in the fastener, as well as for the determination of highest and lowest normal compressive stress occurring on the face, that is bearing plate when the neutral axis is outside the face that is, the bearing plate. Which of these three possible cases will occur depends solely on the force field occurring in the given cross-section for the dimensioning of the joint. The connection is effected by the face or bearing plate, depending on the task being solved and the bolt fasteners. The expressions for the calculation of the said connections are derived for the general case when all three forces intersecting, M, T and N, in the cross section given for their dimensioning, are other than zero or any one of them is other than zero. The paper also presents a tabular presentation of the results for all of the three possible cases of the force fields, that is, the stress fields most frequently occurring in the civil engineering building practice at these joints.

  6. Asthmagenicity of coal mine roof-bolting resins: an assessment using inhalation provocation tests

    Energy Technology Data Exchange (ETDEWEB)

    Convery, R.; Ward, A.; Ward, R.; Bromly, C.L.; Dennis, J.H.; Stenton, S.C.; Bourke, S.J.; Hendrick, D.J. [University of Newcastle Upon Tyne, Newcastle upon Tyne (United Kingdom). Dept. of Respiratory Medicine

    2001-03-01

    Inhalation provocation tests were used to assess whether the volatile products of an activated resin had caused occupational asthma in a non-random sample of six asthmatic coal miners. The resin system uses the polymerization of polyester and styrene under the influence of the cross-linking agent dibenzoyl peroxide to secure roof, wall and floor bolts in mine tunnels. The tests were conducted sequentially in a double-blind fashion over a 'dose' range which extended just beyond the maximum likely to have been experienced occupationally during a single day's work. The tests were monitored by symptoms, changes in the forced expiratory volume in 1 s (FEV1) and changes in airway responsiveness. All subjects completed the series of tests without any significant decrements in FEV1 or significant increases in airway responsiveness. It was concluded that the use of this resin system is not likely to have been the cause of the asthma in the test subjects, nor in the larger group of miners of which they were a sample, but neither possibility is fully excluded and the participants may not have been adequately representative of other asthmatic coal miners.

  7. Multi-field coupled sensing network for health monitoring of composite bolted joint

    Science.gov (United States)

    Wang, Yishou; Qing, Xinlin; Dong, Liang; Banerjee, Sourav

    2016-04-01

    Advanced fiber reinforced composite materials are becoming the main structural materials of next generation of aircraft because of their high strength and stiffness to weight ratios, and excellent designability. As key components of large composite structures, joints play important roles to ensure the integrity of the composite structures. However, it is very difficult to analyze the strength and failure modes of composite joints due to their complex nonlinear coupling factors. Therefore, there is a need to monitor, diagnose, evaluate and predict the structure state of composite joints. This paper proposes a multi-field coupled sensing network for health monitoring of composite bolted joints. Major work of this paper includes: 1) The concept of multifunctional sensor layer integrated with eddy current sensors, Rogowski coil and arrayed piezoelectric sensors; 2) Development of the process for integrating the eddy current sensor foil, Rogowski coil and piezoelectric sensor array in multifunctional sensor layer; 3) A new concept of smart composite joint with multifunctional sensing capability. The challenges for building such a structural state sensing system and some solutions to address the challenges are also discussed in the study.

  8. Reference evapotranspiration estimates based on minimum meteorological variable requirements of historical weather data

    Directory of Open Access Journals (Sweden)

    Antonio J Steidle Neto

    2015-09-01

    Full Text Available Reference evapotranspiration (ET0 is critical for agricultural and urban planning, irrigation scheduling, regional water balance studies, and agroclimatological zoning. The objective of this study was to estimate ET0 based on methods with minimum meteorological variable requirements and on empirical models to predict solar radiation. These alternative methods were compared to the FAO Penman-Monteith method by using more than 80 yr of historical weather data. Alternative methods were adapted from the standard FAO Penman-Monteith or Priestley-Taylor methods, which allow estimating ET0 when fewer meteorological variables are available. The Hargreaves-Samani method was also analyzed. The mean absolute error, index of agreement, correlation coefficient, and confidence index were used to compare the alternative methods. Results showed that alternative methods based on the maximum and minimum temperatures, sunshine hours, and/ or wind speed are appropriate for estimating ET0 in the region under study.

  9. Advantages and disadvantages of a risk - based regulatory requirement (the experience in Argentina)

    International Nuclear Information System (INIS)

    Argentina has its own nuclear regulations, which include a risk-based criterion curve for the licensing of nuclear installations. This requirement, established in the early '70s, must be fulfilled with a PSA study. It has been applied to several installations, and the advantages and disadvantages of this approach are discussed in the paper through several examples. The main disadvantage is a somehow large amount of PSA work that needs to be performed for the licensing of a nuclear installation. The main advantage is the effective risk reduction that can be achieved by retrofitting the risk-based lessons learned into the design teams (not only for design of systems and components, but also for design of operation, testing and maintenance schemes). (author)

  10. Arts-inspired students sync their assets to a nuts and bolts world: A career mentoring pilot progam

    Science.gov (United States)

    Hudson, Lynn

    This research examined how students who are arts-inspired feel about their futures in a STEM-based work climate. Science, Technology, Engineering, and Math are the nuts and bolts, and in education today, the only avenue touted for our country and our students' success in this 21st century economy. This can be disconcerting to those interested in other fields, like the arts. This study was guided by the following questions in an effort to understand if our artists and arts-inspired students realize their options and importance in this 21st century climate. The pilot study was designed to help improve the students' perception of their abilities or self-efficacy in the STEM areas by introducing STEM professionals as mentors who designed hands-on activities that simulate work in the STEM fields. Research Questions: 1. Do arts-inspired students have an interest in a STEM career area prior to participating in the career mentoring program? 2. Does participation in a STEM career mentoring program improve student's self-efficacy in STEM fields? 3. Does participation in STEM career mentoring program increase student's interest in pursuing STEM-related careers? Lent, Brown and Hackett's Social Cognitive Career Theory and Daniel Pink's, "A Whole New Mind: Why Left-Brainers Will Rule the Future" were used as the theoretical framework for this study. Seventeen African-American girls who were enrolled in the "I AM COMPLETE" summer program participated in the pilot study. Data was collected from the College Foundation of North Carolina Career Interest Explorer and the STEM Career Interest Survey, which served as a pre and post-test. This pilot offered limited support for the hypothesis, however, career mentoring and opportunities for young people to experience careers, especially in the STEM areas must continue to grow. The role that the arts play in this process is pivotal in galvanizing females and minorities to join these professions. It is the hope of this researcher that the

  11. A Knowledge-Based and Model-Driven Requirements Engineering Approach to Conceptual Satellite Design

    Science.gov (United States)

    Dos Santos, Walter A.; Leonor, Bruno B. F.; Stephany, Stephan

    Satellite systems are becoming even more complex, making technical issues a significant cost driver. The increasing complexity of these systems makes requirements engineering activities both more important and difficult. Additionally, today's competitive pressures and other market forces drive manufacturing companies to improve the efficiency with which they design and manufacture space products and systems. This imposes a heavy burden on systems-of-systems engineering skills and particularly on requirements engineering which is an important phase in a system's life cycle. When this is poorly performed, various problems may occur, such as failures, cost overruns and delays. One solution is to underpin the preliminary conceptual satellite design with computer-based information reuse and integration to deal with the interdisciplinary nature of this problem domain. This can be attained by taking a model-driven engineering approach (MDE), in which models are the main artifacts during system development. MDE is an emergent approach that tries to address system complexity by the intense use of models. This work outlines the use of SysML (Systems Modeling Language) and a novel knowledge-based software tool, named SatBudgets, to deal with these and other challenges confronted during the conceptual phase of a university satellite system, called ITASAT, currently being developed by INPE and some Brazilian universities.

  12. 77 FR 71369 - Capital, Margin, and Segregation Requirements for Security-Based Swap Dealers and Major Security...

    Science.gov (United States)

    2012-11-30

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION 17 CFR Part 240 RIN 3235-AL12 Capital, Margin, and Segregation Requirements for Security-Based Swap Dealers and Major Security-Based Swap Participants and Capital Requirements for...

  13. Space-based multifunctional end effector systems functional requirements and proposed designs

    Science.gov (United States)

    Mishkin, A. H.; Jau, B. M.

    1988-01-01

    The end effector is an essential element of teleoperator and telerobot systems to be employed in space in the next decade. The report defines functional requirements for end effector systems to perform operations that are currently only feasible through Extra-Vehicular Activity (EVA). Specific tasks and functions that the end effectors must be capable of performing are delineated. Required capabilities for forces and torques, clearances, compliance, and sensing are described, using current EVA requirements as guidelines where feasible. The implications of these functional requirements on the elements of potential end effector systems are discussed. The systems issues that must be considered in the design of space-based manipulator systems are identified; including impacts on subsystems tightly coupled to the end effector, i.e., control station, information processing, manipulator arm, tool and equipment stowage. Possible end effector designs are divided into three categories: single degree-of-freedom end effectors, multiple degree of freedom end effectors, and anthropomorphic hands. Specific design alternatives are suggested and analyzed within the individual categories. Two evaluations are performed: the first considers how well the individual end effectors could substitute for EVA; the second compares how manipulator systems composed of the top performers from the first evaluation would improve the space shuttle Remote Manipulator System (RMS) capabilities. The analysis concludes that the anthropomorphic hand is best-suited for EVA tasks. A left- and right-handed anthropomorphic manipulator arm configuration is suggested as appropriate to be affixed to the RMS, but could also be used as part of the Smart Front End for the Orbital Maneuvering Vehicle (OMV). The technical feasibility of the anthropomorphic hand and its control are demonstrated. An evolutionary development approach is proposed and approximate scheduling provided for implementing the suggested

  14. Modeling and illustrating requirement prioritization in public e-service development from a value-based perspective

    OpenAIRE

    Avdic, Anders; Lambrinos, Thomas

    2015-01-01

    A major problem in e-service development is the prioritization of the requirements of different stakeholders. The main stakeholders are governments and their citizens, all of whom have different and sometimes conflicting requirements. In this paper, the prioritization problem is addressed by combining a value-based approach with an illustration technique. This paper examines the following research question: How can multiple stakeholder requirements be illustrated from a value-based perspectiv...

  15. Fast tracking ICT infrastructure requirements and design, based on Enterprise Reference Architecture and matching Reference Models

    DEFF Research Database (Denmark)

    Bernus, Peter; Baltrusch, Rob; Vesterager, Johan; Tølle, Martin

    2002-01-01

    The Globemen Consortium has developed the virtual enterprise reference architecture and methodology (VERAM), based on GERAM and developed reference models for virtual enterprise management and joint mission delivery. The planned virtual enterprise capability includes the areas of sales and...... marketing, global engineering, and customer relationship management. The reference models are the basis for the development of ICT infrastructure requirements. These in turn can be used for ICT infrastructure specification (sometimes referred to as 'ICT architecture').Part of the ICT architecture is...... industry-wide, part of it is industry-specific and a part is specific to the domains of the joint activity that characterises the given Virtual Enterprise Network at hand. The article advocates a step by step approach to building virtual enterprise capability....

  16. Higher order thinking skills competencies required by outcomes-based education from learners.

    Science.gov (United States)

    Chabeli, M M

    2006-08-01

    Outcomes-Based Education (OBE) brought about a significant paradigm shift in the education and training of learners in South Africa. OBE requires a shift from focusing on the teacher input (instruction offerings or syllabuses expressed in terms of content), to focusing on learner outcomes. OBE is moving away from 'transmission' models to constructivistic, learner-centered models that put emphasis on learning as an active process (Nieburh, 1996:30). Teachers act as facilitators and mediators of learning (Norms and Standards, Government Gazette vol 415, no 20844 of 2000). Facilitators are responsible to create the environment that is conducive for learners to construct their own knowledge, skills and values through interaction (Peters, 2000). The first critical cross-field outcome accepted by the South African Qualification Framework (SAQA) is that learners should be able to identify and solve problems by using critical and creative thinking skills. This paper seeks to explore some higher order thinking skills competencies required by OBE from learners such as critical thinking, reflective thinking, creative thinking, dialogic / dialectic thinking, decision making, problem solving and emotional intelligence and their implications in facilitating teaching and learning from the theoretical perspective. The philosophical underpinning of these higher order thinking skills is described to give direction to the study. It is recommended that a study focusing on the assessment of these intellectual concepts be made. The study may be qualitative, quantitative or mixed methods in nature (Creswell 2005). PMID:17131612

  17. A Survey of System Architecture Requirements for Health Care-Based Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Abraham O. Fapojuwo

    2011-05-01

    Full Text Available Wireless Sensor Networks (WSNs have emerged as a viable technology for a vast number of applications, including health care applications. To best support these health care applications, WSN technology can be adopted for the design of practical Health Care WSNs (HCWSNs that support the key system architecture requirements of reliable communication, node mobility support, multicast technology, energy efficiency, and the timely delivery of data. Work in the literature mostly focuses on the physical design of the HCWSNs (e.g., wearable sensors, in vivo embedded sensors, et cetera. However, work towards enhancing the communication layers (i.e., routing, medium access control, et cetera to improve HCWSN performance is largely lacking. In this paper, the information gleaned from an extensive literature survey is shared in an effort to fortify the knowledge base for the communication aspect of HCWSNs. We highlight the major currently existing prototype HCWSNs and also provide the details of their routing protocol characteristics. We also explore the current state of the art in medium access control (MAC protocols for WSNs, for the purpose of seeking an energy efficient solution that is robust to mobility and delivers data in a timely fashion. Furthermore, we review a number of reliable transport layer protocols, including a network coding based protocol from the literature, that are potentially suitable for delivering end-to-end reliability of data transmitted in HCWSNs. We identify the advantages and disadvantages of the reviewed MAC, routing, and transport layer protocols as they pertain to the design and implementation of a HCWSN. The findings from this literature survey will serve as a useful foundation for designing a reliable HCWSN and also contribute to the development and evaluation of protocols for improving the performance of future HCWSNs. Open issues that required further investigations are highlighted.

  18. Development of system based code (2). Application of reliability target for configuration of ISI requirement

    International Nuclear Information System (INIS)

    The concept of System Based Code (SBC) has been proposed to achieve compatibility in matters of reliability, safety, and cost of fast breeder reactors (FBRs). This code extends the present structural design standard to include the broad areas such as load setting, fabrication, inspection, and maintenance related to FBR design and operation. Therefore, a quantitative index that can correlate these different areas is required. One such index is the probability of failure. The determination of a target value is also one of the key points to implement the SBC concept. We have proposed a new method to determine reliability targets for structures and components in FBR plants from the viewpoint of safety. Analysis models based on probabilistic safety assessments are used in the method for determining reliability targets. In this study, the effectiveness of the probability of failure as an index and the reliability targets produced using the new method are investigated through a trial setting of an in-service inspection (ISI) requirement for a reactor vessel. The probability of failure due to fatigue-creep interaction is calculated using a Monte Carlo simulation. The reliability targets for failure related to the risks arising from internal initiating events are derived using the new method. The summation of the probability of failure and of the reliability targets up to the end of the in-service period enables us to compare them directly. The results show that the reactor vessel has sufficient reliability even without an ISI. Through this example, we demonstrate that the probability of failure is a promising index and that reliability targets derived using the new method are compatible with SBC. (author)

  19. The practical training of students - x-ray technicians and requirements to mentors in clinical bases

    International Nuclear Information System (INIS)

    Full text: Introduction: Training of X-ray technicians in Bulgaria takes place in the Medical Colleges to Medical Universities. It's purpose is providing professional training of students in the area of diagnostic imaging, nuclear medicine and radiotherapy. Practical training is based on the scientific and theoretical knowledge and skills and is organized in pedagogic environment, adequate to regularities for a gradual formation of practical skills and habits. The practical training and pre-graduation internship are performed in 1895 from total of 3810 hours, which represents about fifty percent of all training of X-ray technicians. Students are in groups of 2-4 students. Practical training is organized, accomplished and monitored by the teacher training practice with the help of a mentor in the clinical base. Purpose: To present the tasks of practical training of students - X-ray technicians and the requirements for the personal characteristics and activity of mentors. Materials and methods: Documentary method has been used. Literature and normative documents related to the practical training of students in 'X-ray technician' of Medical Colleges have been studied. The job descriptions of senior clinical X-ray technicians have been examined carefully. Results: By analyzing literature sources, we have structured the tasks of practical training and pre-graduation internship of students - X-ray technicians, also we have described the requirements for personal qualities of mentors and systematize the activities they perform. Conclusion: Practical training plays an important role in adaptation of young X-ray technicians to the conditions of medical work, improving their skills and habits, and to the development of specific practical skills for being able to respond to emergency conditions and to solve complicated practical situations. The mentor is the supervisor and the controller of interns who helps this happen through his own example, qualities and attitudes towards

  20. Spallation-based science and technology and associated nuclear data requirements

    International Nuclear Information System (INIS)

    Rapid advances in accelerator technology in recent years promise average proton beam currents as high as 250 mA with energies greater than one GeV. Such an accelerator could produce very high intensities of neutrons and other nuclear particles thus opening up new areas of science and technology. An example is the efficient burning of transuranic and fission product waste. With such a spallation-burner it appears that high-level waste might be converted to low-level waste on a time scale comparable to the human lifespan at a reasonable additional cost for electric power generation. The emphasis of this paper is on the design of a high power proton target for neutron production, on the nuclear data needed to operate this target safely and effectively, and on data requirements for transmutation. It is suggested that a pilot facility consisting of a 1.6 GeV accelerator and target operating at 25 ma is the next major step in developing this technology. Bursts of protons near the terawatt level might also be generated using such an accelerator with a proton accumulator ring. Research prospects based on such proton bursts are briefly described. The status of established nuclear data needs and of accelerator-based sources for nuclear data measurements is reviewed. 6 refs., 8 figs., 2 tabs