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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 microprocessor based portable bolt tension monitor

    Science.gov (United States)

    Perey, D. F.

    1991-01-01

    A bolt tension monitor (BTM) which uses ultrasonics and a pulsed phase locked loop circuit to measure load-induced acoustic phase shifts which are independent of friction is described. The BTM makes it possible to measure the load in a bolt that was tightened at some time in the past. This capability to recertify a load after-the-fact will help to insure the integrity of a bolted joint.

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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 ...

  14. 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.

  15. 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.

  16. 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)

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. 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)

  17. 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.

  18. 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

  19. Nonlinear Progressive Damage Analysis of Notched or Bolted Fibre-Reinforced Polymer (FRP Laminates Based on a Three-Dimensional Strain Failure Criterion

    Directory of Open Access Journals (Sweden)

    Yue Liu

    2014-03-01

    Full Text Available Notching and bolting are commonly utilised in connecting fibre-reinforced polymer (FRP laminates. These mechanical methods are usually superior to other connections, particularly when joining thick composite laminates. Stress distributions, damage modes and ultimate strengths in notched or bolted FRP laminate designs are of particular interest to the industrial community. To predict the ultimate strengths and the failure processes of notched or bolted composite laminates, nonlinear progressive damage analyses (PDA based on the finite element method (FEM at the meso-scale level are performed in this paper. A three-dimensional strength criterion in terms of strains, which can distinguish different damage modes, was developed and adopted in the analysis model to detect damage initiation in the laminates. Different material degradation methods and the influence of cohesive layers were discussed and compared with results of verification experiments. The results showed that the analysis model that used the succinct strength criterion proposed in this paper could properly predict the damage initiation and the ultimate strengths of notched or bolted FRP laminates. The errors between the numerical results and experimental data were small. The material degradation method with continuum damage mechanics (CDM-based exponential damage factors using the damage index as the independent variable achieved greater accuracy and convergence than the method with CDM-based exponential damage factors using the square index as the independent variable or than the method with constant damage factors. Adding cohesive layers in the model had negligible influence on the final results, largely because the succinct analysis model proposed in this paper is sufficiently accurate in cases of small delamination.

  20. Dynamic and Stability of Harmonic Driving Flexible Cartesian Robotic Arm with Bolted Joints Based on the Sensitivity and Multiple Scales Method

    Directory of Open Access Journals (Sweden)

    Yufei Liu

    2015-01-01

    Full Text Available Flexible Cartesian robotic arms (CRAs are typical multicoupling systems. Considering the elastic effects of bolted joints and the motion disturbances, this paper investigates the dynamic and stability of the flexible CRA. With the kinetic energy and potential energy of the comprising components, Hamilton’s variational principle and Duhamel integral are utilized to derive the dynamic equation and vibration differential equation. Based on the proposed elastic restraint model of the bolted joints, boundary conditions and mode equations of the flexible CRA are determined with using the principle of virtual work. According to the mode frequencies and sensitivities analysis, it reveals that the connecting stiffness of the bolted joints has significant influences, and the mode frequencies are more sensitive to the tensional stiffness. Moreover, describing the motion displacement of the driving base as combination of an average motion displacement and a harmonic disturbance, the vibration responses of the system are studied. The result indicates that the motion disturbance has obvious influence on the vibration responses, and the influence enhances under larger accelerating operations. The multiple scales method is introduced to analyze the parametric stability of the system, as well as the influences of the tensional stiffness and the end-effector on the stability.

  1. 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.

  2. 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.

  3. 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...... change to the bolt head and the nut has the positive indirect effect of increasing the member stiffness, all leading to a smaller joint stiffness factor....

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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...

  11. 基于ADAMS的枪机碰撞力研究%Bolt's Impact Simulation Based on ADAMS

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    In this paper ,the simple model of the barrel and automation was established by ADAMS ,the counter-recoil velocity and the mass of bolt and bolt box were defined by Impact function in ADAMS ,and the accurate control of step size and interpolation algorithm was realized ,then the counter-recoil collision force was obtained .%  建立由枪管和自动机构件组成的简易模型,通过在ADAMS中进行动力学仿真,赋予枪机和枪机框实际的复进到位速度和质量,利用ADAMS中的Impact函数对参数进行设置,并对求解步长和插值算法等进行精确控制,对结果进行测量,得到了枪机复进到位的碰撞力。

  12. 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.

  13. 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.

  14. 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 ...

  15. 基于图像识别技术的螺栓裂缝识别系统研究%The Research of Bolt Cracks Discern System based on Image Recognition Technology

    Institute of Scientific and Technical Information of China (English)

    李亚琳; 王玉增; 李柏震; 刘双源

    2013-01-01

    提出了一种基于图像识别技术的螺栓裂缝非接触识别技术.利用高精度工业相机对待检螺栓进行拍摄,然后采用细化、提高曝光度、图像分割等技术对拍摄到的图片进行处理,获取图像特征,最终达到识别裂缝的目的.实验表明,将图像识别技术应用于螺栓裂缝识别领域,可以大大简化识别步骤,提高识别精度,为螺栓裂缝检测提供了新的发展方向.%Propose a non-contact identification of bolt crack based on image recognition technology. Take photo of every bolt waiting for the detection with high-precision industrial cameras, then process the photos with image thinning, improve exposure, edge detection technology, so we can get the image feature, and finally achieve the purpose of crack identification. The experiment shows that the use of image recognition technology in bolt cracks identification can greatly simplify the identification step, improving recognition accuracy, and provides a new direction of development for the bolt cracks detection.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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...

  7. 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.

  8. Ultrasonic testing of core baffle former bolts of the core tanks of pressurised water reactors; Ultraschallpruefung von Kernumfassungsschrauben der Kernbehaelter von Druckwasserreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Bies, Christian M.; Alaerts, Louis; Bonitz, Frank W. [Westinghouse Electric Germany GmbH, Mannheim (Germany); Devlin, Russell S.; Minogue, Patrick [WesDyne International, Madison, PA (United States)

    2013-07-01

    This article presents the MIDAS VI testing robot used by Westinghouse / WesDyne. This is a remotely operated underwater vehicle which positions ultrasonic probes under camera control. This vehicle makes it possible to substantially reduce the time required for setting up and preparing ultrasonic tests on core baffle former bolts. It has also accelerated the test procedure itself. Test methods have also been developed for bolt types which were hitherto considered incapable of being tested. One of these methods is based on a phased array probe. The article also reports on experiences gained over the course of years in testing core baffle former bolts in European nuclear power plants using the SUPREEM testing robot.

  9. 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。

  10. 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.

  11. 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......, but with finite element (FE) and contact analysis, it is possible to find the stiffness of the member. In the case of many connections and for practical applications, it is not suitable to make a full FE analysis. The purpose of the present paper is to find simplified expressions for the stiffness of the member......, including the case when the width of the member is limited. The calculation of the stiffness is based on the FE, including the solution to the contact problem, and we express the stiffness as a function of the elastic energy in the structure, whereby the definition of the displacements related...

  12. 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)

  13. 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.

  14. 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)

  15. 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.

  16. 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.

  17. 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.)

  18. 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)

  19. 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.

  20. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wieser, G.; Qiao Linan; Eberle, A.; Voelzke, H. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

    2004-07-01

    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

  2. Removable Type Expansion Bolt Innovative Design

    Science.gov (United States)

    Wang, Feng-Lan; Zhang, Bo; Gao, Bo; Liu, Yan-Xin; Gao, Bo

    2016-05-01

    Expansion bolt is a kind of the most common things in our daily life. Currently, there are many kinds of expansion bolts in the market. However, they have some shortcomings that mainly contain underuse and unremovement but our innovation of design makes up for these shortcomings very well. Principle of working follows this: expansion tube is fixed outside of bolt, steel balls and expansion covers are fixed inside. Meanwhile, the steel balls have 120° with each other. When using it ,expansion cover is moved in the direction of its internal part. So the front part of expansion bolt cover is increasingly becoming big and steel halls is moved outside. Only in this way can it be fixed that steel balls make expansion tube expand. When removing them, expansion bolt is moved outside. So the front part of expansion bolt cover is gradually becoming small and steel balls moves inside, after expansion tube shrinks, we can detach them.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. Agent Based Multiviews Requirements Model

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on the current researches of viewpoints oriented requirements engineering and intelligent agent, we present the concept of viewpoint agent and its abstract model based on a meta-language for multiviews requirements engineering. It provided a basis for consistency checking and integration of different viewpoint requirements, at the same time, these checking and integration works can automatically realized in virtue of intelligent agent's autonomy, proactiveness and social ability. Finally, we introduce the practical application of the model by the case study of data flow diagram.

  8. 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.

  9. Dynamic Characteristics Analysis of Bolted Joints Based on Wavelet Analysis%基于小波分析的螺栓联接结构的动态特性分析

    Institute of Scientific and Technical Information of China (English)

    闫航瑞; 曾国英; 赵登峰

    2012-01-01

    Wavelet packet analysis is used to extract the acceleration signals of the bolted joints structure under the peening excitation which contains a natural frequency.The dynamic characteristics which change along with the bolt loose are analyzed by the frequency band signals of that CWT.The experimental system is built based on the Premax data acquisition and analysis equipment Based on the time-frequency characteristic analysis of response signals,the frequency bandwidth of(320~480 )Hz is chosen as the analyzed frequency band and that is restructured. Then, under different connection condition, the time-domain signals within the bandwidth of (320~480)Hz are analyzed by the CWT.The result of the analysis shows that the looseness has a tremendous influence on the dynamic characteristics of the bolted joints structure in the peening vibrational environment, which is ,the smaller the preloading, the faster the signal attenuation, and the greater the structural damping,the more wave energy dissipation,with nonlinear characteristics enhanced.%利用小波包分析技术提取敲击状态下搭接梁螺栓联接结构包含某一固有频率的振动加速度信号,根据该频段信号的连续小波变换(CWT,1-D Continuous Wavelets)分析螺栓联接结构随着预紧力变化的动态特性.首先基于Premax大型数据采集与分析系统搭建实验平台;之后根据振动信号的时频特性选取(320~480)Hz作为分析频段并进行单支重构;然后对不同连接状况下在该频段的时域信号进行一维连续小波变换.分析结果发现螺栓松动变化与其结构的动态特性密切相关,在敲击下,预紧力越小,信号衰减越快,其结构阻尼越大,表示联接结构的能量耗散增大,系统非线性增强.

  10. 21 CFR 137.280 - Bolted yellow corn meal.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Bolted yellow corn meal. 137.280 Section 137.280... Flours and Related Products § 137.280 Bolted yellow corn meal. Bolted yellow corn meal conforms to the definition and standard of identity prescribed by § 137.255 for bolted white corn meal except that...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Theoretical and experimental research on the vibration characteristics excited at the end of pre-stressed rock-bolt%预应力锚杆端部受激振动特性的理论与实验研究

    Institute of Scientific and Technical Information of China (English)

    李青锋; 朱川曲

    2015-01-01

    In order to improve the random and non-destructive dynamic detection accuracy of pre-stress of rock-bolt, according to pre-stressed rock-bolt mechanical characteristics loaded on the sur-rounding rock, the mechanical model of non-destructive dynamic detection of pre-stress of rock-bolt has been firstly put forward. Secondly, based on elastic dynamics and structural dynamics, the theoretical analysis of vibration mechanical model of pre-stressed rock-bolt has been presented when it is stimu-lated at its outer end, and the pre-stress formula of pre-stressed rock-bolt has been obtained. Finally, with the simulation of surrounding rock with concrete block, and anchored resin rock-bolt in the re-served hole of concrete block, the non-prestressed and prestressed rock-bolt have been detected by non-destructive dynamic detection instrument. The result has shown that the cantilever dynamics model is consistent with vibration mechanics characteristics of pre-stressed rock-bolt when stimulated at its outer end, and that test error basically meets the requirement of the field.%为了提高预应力锚杆预应力的随机、无损动力检测精度,首先根据预应力锚杆对围岩的加载力学特点,提出了预应力锚杆的预应力无损动力检测力学模型;然后基于弹性动力学和结构动力学对预应力锚杆外端受激振动力学模型进行理论分析,得到了预应力锚杆的预应力计算式;最后以混凝土试块模拟围岩,并在混凝土试块预留孔中锚固了树脂锚杆,采用动力测试仪对无预应力和有预应力锚杆进行无损动力测试。结果表明,悬臂梁式动力学模型符合预应力锚杆外端受激振动力学特点,测试误差基本满足现场要求。

  2. 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.)

  3. 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.

  4. 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...

  5. 21 CFR 137.255 - Bolted white corn meal.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Bolted white corn meal. 137.255 Section 137.255... Flours and Related Products § 137.255 Bolted white corn meal. (a) Bolted white corn meal is the food... of the finished bolted white corn meal does not exceed by more than 0.3 percent the fat content...

  6. 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.

  7. 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.

  8. Inedible Nuts and Non-Lightning Bolts

    Science.gov (United States)

    Rynone, William

    2010-01-01

    In this article, the author provides detailed information on a wide variety of commonly used screws, bolts, and other fasteners. The information has been gathered in his engineering career and outside interests (maintenance on his car and airplane, and woodworking). The topic should be of interest to students and educators in many technical…

  9. 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.

  10. 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.

  11. BOLTS: a BiOphysical Larval Tracking System for Measuring Dispersal Characteristics and Marine Population Connectivity

    Science.gov (United States)

    Paris, C. B.; Srinivasan, A.; Kourafalou, V.; Sponaugle, S.; Cowen, R. K.

    2008-12-01

    While metapopulation research with hypothetical dispersal matrices has shown how the scales of larval dispersal, transport processes, local recruitment, and temporal and spatial variability in dispersal influence population persistence, the pattern of demographic connectivity produced by larval dispersal is still a key uncertainty. To address this problem, a coupled bio-physical model has been developed that quantifies the degree of connectivity between populations. Such spatially explicit models, forced by dynamic currents coupled to a realistic seascape and life history traits, produce dispersal kernels for a range of scales over which dispersal is practically unquantifiable by current empirical methods. The BiOphysical Larval Tracking System (BOLTS) presented here allows a Lagrangian stochastic individual-based model (IBM) to be coupled via OPENDAP framework to any 3-dimensional fields of circulation models including to domains of various resolutions through 'Lagrangian nesting'. We demonstrate the capabilities of the software in measuring the characteristics of dispersal and evaluating the variability of larval connectivity through two examples at different scales: 1) Caribbean-scale simulations of BOLTS using the large scale (resolution ~7 km) Hybrid Coordinate Ocean Model (HYCOM) from the Global Data Assimilative Experiment (GODAE) provide us with expected connectivity patterns of a reef building coral. By seeding the model with a large number of active particles, it is possible to assemble dispersal kernels and migration matrices from the start (spawning) and the end point (settlement) of individual particle trajectories. Any single run is a stochastic realization of a probabilistic process, thus the full probability density function (pdf) of the kernel requires averaging over many dispersal events. The model output is further corroborated with empirical measures of gene flow among coral colonies around the Caribbean. 2) Coastal-scale simulations of BOLTS

  12. 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)

  13. 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.

  14. 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.

  15. 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.)

  16. Failure analyses of composite bolted joints

    Science.gov (United States)

    Wilson, D. W.; Gillespie, J. W.; York, J. L.; Pipes, R. B.

    1980-01-01

    The complex failure behavior exhibited by bolted joints of graphite epoxy (Hercules AS/3501) was investigated for the net tension, bearing and shearout failure modes using combined analytical and experimental techniques. Plane stress, linear elastic, finite element methods were employed to determine the two dimensional state of stress resulting from a loaded hole in a finite width, semiinfinite strip. The stresses predicted by the finite element method were verified by experiment to lend credence to the analysis. The influence of joint geometric parameters on the state of stress and resultant strength of the joint was also studied. The resulting functional relationships found to exist between bolted joint strength and the geometric parameters, were applied in the formulation of semiempirical strength models for the basic failure modes. A point stress failure criterion was successfully applied as the failure criterion for the net tension and shearout failure modes.

  17. 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...

  18. Finite element analysis of bolted flange connections

    Science.gov (United States)

    Hwang, D. Y.; Stallings, J. M.

    1994-06-01

    A 2-D axisymmetric finite element model and a 3-D solid finite element model of a high pressure bolted flange joint were generated to investigate the stress behaviors. This investigation includes comparisons for axisymmetric loading of both the 2-D and 3-D models, the effects of non-axisymmetric bolt pretensions in the 3-D models, and the differences between 2-D and 3-D models subjected to non-axisymmetric loading. Comparisons indicated differences in von Mises stress up to 12% at various points due to the non-axisymmetric bolt pretensions. Applied bending moments were converted to equivalent axial forces for use in the 2-D model. It was found that the largest von Mises stresses in 3-D model did not occur on the side of the connection where the bending stresses and applied axial stresses were additive. Hence, in the 2-D model where the equivalent axial force (for bending moment) and applied axial forces were added, the 2-D model under estimated the maximum von Mises stress obtained from the 3-D model by 30%.

  19. Mechanism analysis of shear deformation of joint bolt based on elastic-plastic theory%基于弹塑性理论的节理处锚杆剪切变形机理分析

    Institute of Scientific and Technical Information of China (English)

    马超甫; 冯涛; 姚琦; 王平; 廖泽

    2016-01-01

    为了研究节理面处锚杆的剪切变形机制,建立了节理岩体中锚杆的受力模型,对锚杆在节理面处的剪切变形进行了理论分析,利用单位载荷法推导了节理面处锚杆竖向位移与载荷、节理宽度、材料性质间的关系。理论分析表明,节理岩体中锚杆的剪切变形过程为:小挠度变形阶段、弹塑性剪切变形阶段、塑性铰阶段;剪切变形至塑性铰阶段时,节理面处杆体将出现两个塑性铰;节理面处锚杆具有一段结构对称、载荷反对称部分;节理宽度对节理处杆体的弹性区、弹塑性区的分界面位置存在线性影响。%The stressing model of anchor bolt in jointed rock mass is established to study the shear deformation mechanism of jointed rock bolts,and the shear deformation at the joints is analyzed theoretically. Relationships between vertical displacement and load,and joint width and material properties of anchor bolt in the vicinity of the joint plane are deducted.The theoretical analysis shows that the shear deformation process of anchor bolt in jointed rock has the following stages,i.e.small deflection deformation stage,elastic -plastic shear deformation stage,and plastic hinge stage.In plastic hinge stage,two plastic hinges will appear on the anchor bolt near the joint plane.The anchor bolt has a section of body of symmetrical structure and anti -symmetrical load near the joint plane.The joint width has linear effect on Interface position between elastic region and elastic-plastic region near the joint.

  20. 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.

  1. Autoregressive Model-based Bolted Joints Fault Diagnosis%基于自回归模型的螺纹连接松动诊断

    Institute of Scientific and Technical Information of China (English)

    张言; 曾国英; 赵登峰; 栗明燕

    2012-01-01

    应用自回归模型分析法兰螺纹连接上下壳体的差值信号,进行螺纹连接松动诊断。在螺纹连接模型上,改变某一个螺钉的预紧力,将正常工况下的差值信号作为参考总体,并以此建立AR模型,其他预紧力下的差值信号为待检总体,分别计算参考总体与待检总体之间的Euclide距离和Mahalanobis距离。分析结果表明:基于自回归模型的几何距离是有效的螺纹连接松动指标,可以用于螺纹连接故障诊断。%An autoregressive model-based technique is proposed to detect flange screw-connected joints fault.The AR model can be validated by reference population which is defined as difference signal of normal conditions.The difference signal obtained in other preload conditions is defined as inspection population.The analyses of Euclide distance and Mahalanobis distance between reference population and inspection population indicate that autoregressive model-based geometrical distance is considered as effective index of screw-connected joints fault and it can be used to detect screw-connected joints fault.

  2. 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....

  3. 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].

  4. 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.

  5. 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.

  6. 9 CFR 313.15 - Mechanical; captive bolt.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Mechanical; captive bolt. 313.15 Section 313.15 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.15 Mechanical; captive bolt....

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

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Pedersen, Pauli

    2008-01-01

    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...

  8. 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)

  9. 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.

  10. 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.

  11. 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.

  12. Richard H. Bolt-Mentor and colleague

    Science.gov (United States)

    Wetherill, Ewart A.

    2003-04-01

    Of his many accomplishments in acoustics, perhaps one of Richard H. Bolt's greatest legacies will prove to be his contribution, both directly and through his teaching, to everyday hearing conditions in buildings. In a discipline that attempts to bridge the technical and cultural gap between a pure science and the pragmatic and often-haphazard process of building design, he combined a deep understanding of both professions with an ability to communicate complex ideas that is reminiscent of Wallace Clement Sabine. His welcoming enthusiasm and humility enabled him to attract and to work well with people of complementary talents, in both theoretical research and the gritty details of a consulting practice, as well as to envision the potential of still-unexplored subjects. A logical outcome of this combination was the profoundly influential technical group known as BBN, whose pioneering integration of acoustics with building technology is echoed by many consulting groups throughout the world.

  13. 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.

  14. Requirements engineering-based conceptual modeling

    NARCIS (Netherlands)

    Insfrán, E.; Pastor, O.; 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

  15. 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

  16. Roof strata horizontal movement assessed by instrumented bolts monitoring and FEM modelling

    Energy Technology Data Exchange (ETDEWEB)

    Pytel, W. [CBPM ' ' Cuprum' ' OBR (Poland)

    2004-07-01

    Results of investigation concerning in-situ assessment of roof strata 3-d movement in the vicinity of a selected hard rock yielding pillar are presented in the paper. Based on laboratory calibration tests it was possible to establish the analytical relationships between the load (or stress) increment within the bolt rod, and the extensometer read-out box increment for all pairs of extensometers, glued-in at five measurement horizons. These relationships were a base for the assessment of rod axial forces and bending moments in time domain. The finite difference method technique was used for bolt rod deflection (lateral) assessment based on the elastic beam (rod) deflection differential equation solution involving the values of in-situ measurement based bending moments. In-situ obtained measurement data were supplemented with numerical experiments performed in a large geometric scale. The numerical models based on the 3-d finite element method, represented the roof bolting-pillar-floor systems in the in-situ measurement sites conditions.

  17. 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.

  18. 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?

  19. 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.

  20. 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…

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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)

  6. 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.

  7. 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...

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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.

  16. 锚杆尾部断裂机制和防破断方法应用%Fracture Mechanism of the Bolt Tail and Applications of Anti-breaking Methods

    Institute of Scientific and Technical Information of China (English)

    李夕兵; 马少维; 马春德; 李金跃; 郭阳

    2013-01-01

    基于岩体弹性能释放对锚杆的冲击作用,采用冲击动力学中刚性块对杆轴向碰撞的应力解,推导出了锚杆断裂的4种围岩应力条件.在此基础上分析了岩石弹性模量、锚杆弹性模量、锚杆直径与岩石泊松比等因素对锚杆断裂的影响.分析结果显示:在这4种围岩应力条件中,杆头被一次冲断基本上是不可能的,由于其他几种锚杆断裂时的围岩应力条件很接近,所以在实际中锚杆尾部被一次冲断的可能性最高,这也印证了锚杆尾部容易断裂的观点;另外,锚杆断裂的围岩应力条件受岩石弹性模量、岩石泊松比、岩石密度、锚杆弹性模量、锚杆密度、锚杆直径等因素的影响,其中影响较大的是岩石弹性模量与锚杆弹性模量的比值、锚杆直径和岩石泊松比;锚杆尾部断裂的围岩应力条件对于改进锚杆形式、优化锚杆力学性质有理论指导意义.最后,以马路坪矿的巷道工程为例,说明了锚杆防破断方法的具体应用,收到了良好的效果,可以在实际工程中推广应用.%Based on the bolt impacted by the elastic energy of rock mass and the stress solution that a rigid block collides with rod along axially in impact dynamics is adopted; four stress conditions of rock mass are derived before the bolt is fractured. And on the basis, several factors, including elastic modulus of rock, elastic modulus of bolt, diameter of bolt, and Poisson's ratio of rock, are discussed. The analytical results show as follows: In four stress conditions of rock mass, it is impossible that bolt head is directly fractured, but the rest parts have high possibility. In addition, the rest bolts have the similar stress conditions of rock mass, therefore it has a high possibility that the bolt tail is directly fractured, it also confirms with the view that bolt tail is easily broken; Besides, before the bolt is fractured, the stress condition of rock mass is affected by

  17. 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

  18. 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.

  19. 12 CFR 932.3 - Risk-based capital requirement.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Risk-based capital requirement. 932.3 Section 932.3 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOME LOAN BANK RISK MANAGEMENT AND CAPITAL STANDARDS FEDERAL HOME LOAN BANK CAPITAL REQUIREMENTS § 932.3 Risk-based capital requirement....

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. Improved wire stiffness with modified connection bolts in Ilizarov external frames: a biomechanical study.

    Science.gov (United States)

    Gessmann, Jan; Jettkant, Birger; Königshausen, Matthias; Schildhauer, Thomas Armin; Seybold, Dominik

    2012-01-01

    Frame stability in Ilizarov external fixators is mainly dependent on the tension of the transosseous wires, which are clamped to the ring by connection bolts. It was the purpose of this biomechanical study to investigate the holding capacity of a modified bolt design featuring a ruffled wire-bolt interface (TrueLok™) and its influence on wire stiffness in comparison with that of classic bolts featuring a smooth, unruffled wire-bolt interface. Six different ring and bolt configurations were tested using a simplified model consisting of a single ring and wire. The holding capacity at two different tightening torques (10 and 14 Nm) of classic cannulated bolts (CB) and slotted bolts (SB) was determined on Ilizarov and Taylor Spatial Frame (TSF™) rings, whereas the modified TrueLok™ CBs and SBs were used with the TrueLok™ rings. The wire stiffness was calculated via a regression analysis of the load-displacement graphs. The modified TrueLok™ bolts demonstrated significantly better slippage resistance than the classic bolts in all configurations and wire stiffness was significantly higher in the TrueLok™ frame set-ups. After maximum loading, all of the wires showed plastic deformation, including constant wire deflection and dent marks at the clamped wire ends. In conclusion, the decrease in wire stiffness can be explained mainly as a result of wire slippage, but plastic deformation and material yielding also contribute. The relatively simple modification made by roughening the wire-bolt interface results in improved holding capacity and wire stiffness. A frame that contains these modified TrueLok™ bolts should provide improved mechanical stiffness.

  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. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Degradation and failure of bolting in nuclear power plants: Volume 2: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, R.E.

    1988-04-01

    A four-year program to resolve the generic safety issue of bolting degradation and failure in nuclear power plants has developed guidelines for material selection, bolting preload control, and plant operation, as well as a realistic method for evaluating the structural integrity of bolted joints. These measures can help improve plant availability while reducing radiation exposure and costs of maintenance and inspection. This report provides the technical basis for resolution of the generic issue of bolting degradation and failure in nuclear power plants.

  12. 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 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 bolted...

  13. 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.

  14. 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.

  15. 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.

  16. 一种螺栓拉伸器校准方法研究%A Calibration Method Research for Bolt Tensioners

    Institute of Scientific and Technical Information of China (English)

    赵兴亮; 杨思凡; 李玮; 陈宝有

    2015-01-01

    A calibration method for bolt tensioners is presented. According to the theory of Newton's Third Law, the calibration device is researched and designed to calibrate the bolt tensioners. The meas-urement error and repeatability analysis and uncertainty evaluation show the linearity is good. Considering the measurement error is within ±1%, which meets the calibration requirements for bolt tensioners, the designed calibration device is capable to carry out the calibration work for bolt tensioners.%介绍了螺栓拉伸器的一种校准方法,运用牛顿第三定律的基本原理,研究并设计了一种拉伸器校准装置对螺栓拉伸器进行校准,通过对实验结果的误差和重复性分析,以及不确定度评定,表明该拉伸器校准装置具有良好的线性度,测量误差在±1%以内,符合螺栓拉伸器校准要求,达到了校准螺栓拉伸器的目的,可以开展螺栓拉伸器校准工作。

  17. 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.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    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 real-time system against a scenario-based requirement reduces to a classical real-time model checking......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...

  19. 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

  20. 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.

  1. Synthetical deformation analysis of anchor bolt in jointed rock mass%节理岩体锚杆的综合变形分析

    Institute of Scientific and Technical Information of China (English)

    张伟; 刘泉声

    2012-01-01

    在总结国内外对节理岩体中锚杆加固机制的试验研究和理论探讨基础上,综合考虑锚杆的切向和轴向变形能力,建立节理锚固锚杆在剪切荷载作用下的变形模型,将节理锚固锚杆的变形区划分为弹性变形段和挤压破坏段,引入表征挤压破坏段长度的变量,对锚杆与岩体的相互作用机制进行理论分析,推导了剪切荷载与剪切位移和轴向荷载与轴向位移的关系.通过分析锚杆的屈服破坏形式,得到了确定挤压破坏段长度的方法.最后,通过算例分析了挤压破坏段长度与锚杆直径、岩体强度、锚固角度等参数的关系,得到了以下结论:(1)节理锚固锚杆抗剪作用的实质是锚杆调动岩体的抗压强度抵抗节理切向荷载.在抗压强度较高的硬岩中,挤压破坏段局限于节理面附近,锚杆影响范围小;而在抗压强度较低的软岩中,挤压破坏段较大,而且会产生较大的剪切变形,锚杆影响范围较大.(2)锚杆屈服破坏形式与岩质和锚杆直径有关.硬质岩体发生剪切屈服,而较软岩体中容易发生弯曲屈服;小直径锚杆一般直接剪切屈服,而大直径锚杆可能发生弯曲屈服.锚杆屈服破坏后出现塑性铰,挤压破坏段范围在节理一侧约为直径的1~2倍,继续增加剪切荷载,挤压破坏段长度不再增大.(3)随岩质的不同,锚杆锚固节理的最优锚固角变化较大.岩质较硬时,最优锚固角度较小,反之则较大.%Based on the former experimental and theoretical researches on the reinforcement mechanisms of anchor bolt in jointed rock mass at home and abroad, and comprehensive considering of the tangential and axial deformability of anchor bolt, a deformation model of joint bolts under shear load is proposed. The deformation of joint bolts is divided into two parts: elastic deformation zone and crushing failure zone. A variable is introduced to express the length of crushing failure zone. Mechanism

  2. 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)

  3. 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.

  4. 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)

  5. 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.

  6. 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

  7. Managing Software Requirements Changes Based on Negotiation-Style Revision

    Institute of Scientific and Technical Information of China (English)

    Ke-Dian Mu; Weiru Liu; Zhi Jin; Jun Hong; David Bell

    2011-01-01

    For any proposed software project,when the software requirements specification has been established,requirements changes may result in not only a modification of the requirements specification but also a series of modifications of all existing artifacts during the development.Then it is necessary to provide effective and flexible requirements changes management.In this paper,we present an approach to managing requirements changes based on Booth's negotiation-style framework for belief revision.Informally,we consider the current requirements specification as a belief set about the systemto-be.The request of requirements change is viewed as new information about the same system-to-be.Then the process of executing the requirements change is a process of revising beliefs about the system-to-be.We design a family of belief negotiation models appropriate for different processes of requirements revision,including the setting of the request of requirements change being fully accepted,the setting of the current requirements specification being fully preserved,and that of the current specification and the request of requirements change reaching a compromise.In particular,the prioritization of requirements plays an important role in reaching an agreement in each belief negotiation model designed in this paper.

  8. 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…

  9. 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)

  10. 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

  11. 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.

  12. Degradation and failure of bolting in nuclear power plants: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, R.E.

    1988-04-01

    These two volumes provide the documentation for industry resolution of the US Nuclear Regulatory Commission (NRC) generic issue B-29, Degradation and Failure of Bolting in Nuclear Power Plants. The issue was identified as a consequence of concerns about the structural integrity of component supports circa 1980. When bolting integrity became a separate issue in 1982, the utility industry responded by forming a Task Group on Bolting under the aegis of the Atomic Industrial Forum (AIF) and the Materials Properties Council (MPC). The AIF/MPC Task Group on Bolting formulated a comprehensive nineteen-task action plan aimed at resolution of the issue, with implementation of the plan, the responsibility of EPRI and the affected Owner's Groups. EPRI organized a matrix-managed Generic Bolted Joint Integrity Program to carry out the research, with the results reported herein.

  13. 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.

  14. 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.

  15. 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.

  16. Tethered Space Satellite-1 (TSS-1): Wound About a Bolt

    Science.gov (United States)

    O'Connor, Brian; Stevens, Jennifer

    2016-01-01

    In the early 1990's US and Italian scientists collaborated to study the electrodynamics on a long tether between two satellites as it moved through the electrically charged portion of Earth's atmosphere called the ionosphere. Potential uses for the electrical current induced in the long wire include power and thrust generation for a satellite, momentum exchange, artificial gravity, deployment of sensors or antennas, and gravity-gradient stabilization. The Tethered Space Satellite (TSS) was a first-of-its-kind experiment with long tethers in space. It consisted of a satellite with science experiments attached to a 12.5 mile long, very thin (0.10 inch diameter) copper wire assembly wound around a spool in the deployer reel mechanism. The whole mechanism sits on a pallet that is installed into the Shuttle bay. At an altitude of 160 nautical miles above earth, the satellite would be deplodeployed from the Shuttle bay by raising it on a boom facing away from Earth. Once cleared of the bay, the deployer mechanism would slowly feed out the 12-plus miles of tether. Scientific data would be collected throughout the operation, after which the satellite would be reeled back in. A receiver spool to catch the 12.5 mile tether as it was being unwound by the deployer reel mechanism was set up to do the system-level test of deployer real mechanism prior to installing the loaded pallet into the Shuttle bay. The system level tests were required before the pallet could be installed into the Space Shuttle cargo bay. A few months before flight, the system level tests, including unreeling and reeling the tether, were completed at Kennedy Space Center (KSC) and the TSS payload was installed onto the Spacelab pallet. Some of this testing equipment was then shipped back to the contractor, Martin Marietta. Integration with the Shuttle began. Systems-level load analyses, which cannot be run until all information about each payload is finalized, was run in parallel with the physical

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. Semantic-Based Requirements Content Management for Cloud Software

    Directory of Open Access Journals (Sweden)

    Jianqiang Hu

    2015-01-01

    Full Text Available Cloud Software is a software complex system whose topology and behavior can evolve dynamically in Cloud-computing environments. Given the unpredictable, dynamic, elasticity, and on-demand nature of the Cloud, it would be unrealistic to assume that traditional software engineering can “cleanly” satisfy the behavioral requirements of Cloud Software. In particular, the majority of traditional requirements managements take document-centric approaches, which have low degree of automation, coarse-grained management, and limited support for requirements modeling activities. Facing the challenges, based on metamodeling frame called RGPS (Role-Goal-Process-Service international standard, this paper firstly presents a hierarchical framework of semantic-based requirements content management for Cloud Software. And then, it focuses on some of the important management techniques in this framework, such as the native storage scheme, an ordered index with keywords, requirements instances classification based linear conditional random fields (CRFs, and breadth-first search algorithm for associated instances. Finally, a prototype tool called RGPS-RM for semantic-based requirements content management is implemented to provide supporting services for open requirements process of Cloud Software. The proposed framework applied to the Cloud Software development is demonstrated to show the validity and applicability. RGPS-RM also displays effect of fine-grained retrieval and breadth-first search algorithm for associated instance in visualization.

  3. 基于单体失效的均布螺栓组非等强度连接对传递动力性能的影响分析%An Influence Analysis for Torque Transfer Function Based on Individual Invalidity and Non-equal Strength in an Uniform Set of Bolted Joint

    Institute of Scientific and Technical Information of China (English)

    朱正德

    2011-01-01

    Taking uniform set of bolted joints connected car engines crankshaft flange / fly wheel for example this article introduces a detailed influence analysis about torque transfer function caused individual invalidity in an uniform set of bolted joint. Then it is realizable to make a quantitative assessment of reliability in this case.%论文以连接发动机曲轴法兰/飞轮的均布螺栓组为例,对其中个别螺栓连接由于某种原因引起的失效,将会给整个螺栓组传递扭矩的功能带来的影响进行了详尽的分析,并给出了风险的定量评估.

  4. 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.

  5. A Complexity measure based on Requirement Engineering Document

    CERN Document Server

    Sharma, Ashish

    2010-01-01

    Research shows, that the major issue in development of quality software is precise estimation. Further this estimation depends upon the degree of intricacy inherent in the software i.e. complexity. This paper attempts to empirically demonstrate the proposed complexity which is based on IEEE Requirement Engineering document. It is said that a high quality SRS is pre requisite for high quality software. Requirement Engineering document (SRS) is a specification for a particular software product, program or set of program that performs some certain functions for a specific environment. The various complexity measure given so far are based on Code and Cognitive metrics value of software, which are code based. So these metrics provide no leverage to the developer of the code. Considering the shortcoming of code based approaches, the proposed approach identifies complexity of software immediately after freezing the requirement in SDLC process. The proposed complexity measure compares well with established complexity...

  6. Development and application of new-type recyclable resin metal bolts%新型可回收树脂金属锚杆的研制与应用

    Institute of Scientific and Technical Information of China (English)

    吴锐; 徐金海; 周保精; 王强

    2011-01-01

    新型可回收树脂金属锚杆弥补了普通树脂锚固式锚杆安装后难拆除的缺陷.经力学性能试验和现场应用,该锚杆具有适应性强、承载力大、可靠性高、综合力学性能好等多项优点,能够满足回采巷道支护的要求.%The new-type recyclable resin metal bolt overcomes the fault that the ordinary resin anchored bolt is difficult to remove once installed The mechanical tests and field applications show that the new-type bolt has strong adaptability, large carrying capacity, high reliability and excellent complex mechanical properties, as well as meets the supporting requirements in mining laneways.

  7. Further development of remote testing of submerged bolts and screws in reactors; Weiterentwicklung der ferngesteuerten Schrauben- und Stiftpruefung unter Wasser in Reaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Mohr, F.; Schirner, G.; Meier, R.; Wiesinger, W. [intelligeNDT Systems und Services, Erlangen (Germany)

    2007-07-01

    Since the eighties, intelligeNDT has been carrying out ultrasonic tests of bolts in reactor containments and pressure vessels both in Germany and abroad. The ultrasonic equipment used belonged to the SAPHIR/SAPHIRplus line. The recording and online evaluation software was adapted to the test requirements and optimized for high test rates and quality-assured documentation. As test manipulator, the 'SUSI' submarine by AREVA NP was used with good results. (orig.)

  8. Method of designing developable surface based on engineering requirement

    Institute of Scientific and Technical Information of China (English)

    YANG Ji-xin; LIU Zhe; LIU Jian

    2006-01-01

    The paper deals with the principle of envelope of a one-parameter plane family to design developable surfaces. Three methods of designing developable surfaces are presented. They are designing a developable surface based on one curve on it and its normal line, designing a developable surface based on two curves on it and designing a developable surface based on one curve and one surface. They meet the requirements of engineering fields.

  9. 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.

  10. 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.

  11. 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.

  12. An Assessment of Extreme Programming Based Requirement Engineering Process

    Directory of Open Access Journals (Sweden)

    Muhammad Khalid

    2013-02-01

    Full Text Available Comprehensive requirement engineering (RE process acts as a backbone of any successful project. RE processes are very complex because most of the requirement engineering documentation is written in natural languages, which are less formal and often distract the designers and developers of the system. To streamline different phases of the software lifecycle, first we need to model the requirement document so that we can analyze and integrate the software artifacts. Designers can ensure completeness and consistency of the system by generating models using the requirement documents. In this paper, we have made an attempt to analyze extreme programming based RE approach to understand its utility in the requirement elicitation phase. In this study, different RE process models are evaluated and a comparison of the extreme programming technique is drawn to highlight the merits of the latter technique over the conventional RE techniques.

  13. 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.

  14. 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.

  15. 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.

  16. 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...... molecule, NO. So far, NO scavenging has only been demonstrated for class 1 non-symbiotic hemoglobins. A direct assay in Arabidopsis leaf cells shows that GLB1 as well as the class 2 non-symbiotic hemoglobin, GLB2, scavenge NO in vivo. NO has also been demonstrated to be a growth stimulating signal...

  17. Towards Value-Based requirements prioritization for software product management

    Directory of Open Access Journals (Sweden)

    Samer I. Mohamed

    2008-07-01

    Full Text Available Meeting stakeholders' requirements and expectations becomes one of the critical aspects on which any software organization in market-driven environment focuses on, and pays a lot of effort and expenses to maximize the satisfaction of their stakeholders. Therefore identifying the software product release contents becomes one of the critical decisions for software product success. Requirements prioritization refers to that activity through which product releases contents that maximize stakeholder satisfaction can be identified [8]. This paper illustrates the Value-Oriented requirement prioritization approach for software product management. The technique proposed in this paper is based on the Hierarchical Cumulative Voting (HCV and Value-Oriented Prioritization (VOP techniques. The proposed technique, Value-Oriented HCV (VOHCV addresses the weakness of HCV through selecting the best candidate requirements for each release not only based on the stakeholder's perceived value as HCV but also in terms of associated anticipated cost, technical risk, relative impact and market-related aspects. The VOHCV also addresses the weakness of VOP through supporting not only requirements flat structure as VOP but also through supporting hierarchical structure. By this means VOHCV inherits the strengths of both VOP and HCV and addresses their weaknesses while selecting the best candidate release requirement, to maximize stakeholders' value and satisfaction [11].

  18. 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.

  19. 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.

  20. 螺纹钢树脂锚杆的研究现状与趋势%Research Status-quo and Tendency of Thread-steel Resin Anchored Bolt

    Institute of Scientific and Technical Information of China (English)

    林健; 康红普

    2009-01-01

    Based on development status-quo of resin anchored bolt in Chinese collieries, this paper firstly presented current problem of thread-steel resin anchored bolt including steel quality, shape, transverse rib and interval of ribs, screw thread and components during production and use. Then, it put forward research key to anchored bolt supporting and problems which should be resolved.%针对近年来我国煤矿树脂锚杆发展现状,指出了目前高强度螺纹钢锚杆钢材质量、外形、横肋及肋间距、尾部螺纹及配套构件在生产及使用过程中存在的问题,并提出今后锚杆支护重点的研究方向和应解决的问题.

  1. Customer requirements based ERP customization using AHP technique

    NARCIS (Netherlands)

    Parthasarathy, S.; Daneva, Maya

    2014-01-01

    Purpose– Customization is a difficult task for many organizations implementing enterprise resource planning (ERP) systems. The purpose of this paper is to develop a new framework based on customers’ requirements to examine the ERP customization choices for the enterprise. The analytical hierarchy pr

  2. 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.

  3. 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)

  4. 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.

  5. 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....

  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. 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

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Crescimanno, P.J.; Keller, K.L.

    1981-03-01

    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.

  15. 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

  16. 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.

  17. 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.

  18. 木结构螺栓连接的力学性能研究进展%Reviews of Mechanical Properties for Timber Bolted Joints

    Institute of Scientific and Technical Information of China (English)

    张俊珍; 钟永; 赵荣军; 周海宾

    2012-01-01

    Bolted connections have been widely used in modern timber structures. Their mechanical properties are very important for designing safe and durable wood structures. The authors have summarized studies on timber bolt connections for predicting failure, as well as modeling strength and mechanical behaviors under fire and seismic conditions. The authors also have made some suggestions for future modeling mechanical behavior and reliability based on previous development in modern timber bolted joints.%螺拴连接已广泛用于现代木结构建筑中,系统研究其力学性能对建筑结构的安全性评估意义重大.本文从螺栓连接强度的预测方法、力学行为模拟、螺栓预紧、螺栓连接的破坏方式,以及抗火抗震条件下的力学性能等方面进行了总结归纳,针对目前的木结构螺栓连接中尚未解决的问题及有待进一步开展的研究项目,建议加强复螺栓连接的力学行为模拟、可靠性评价等研究.

  19. [Pharmacist's requirements for evidence-based self-medication guidelines].

    Science.gov (United States)

    Laven, Anna; Läer, Stephanie

    2013-03-01

    Due to the removal of many pharmaceuticals from the prescription requirement, self-medication implies an increasing responsibility for pharmacists towards their patients. The application of evidence-based guidelines could be a responsible basis for consulting in pharmacies. Evidence-based guidelines represent the systematically accumulated and evaluated facts (the evidence) of desired and undesired effects of pharmaceuticals in the population. We wanted to find out which interest pharmaceutical professionals have in evidence-based guidelines and which are the exact requirements on their content, deducted from public pharmacies everyday demands. With this purpose, three surveys were conducted between March and August 2012, in which 365, 350, and 486 pharmaceutical professionals participated respectively. The results show that pharmacy staff is very interested in evidence based guidelines. Furthermore, they suggest that the pharmacy staff feel safe with the self-diagnosis of the customer, with the consideration of limits of self-medication, as well as with the selection of the--according to own assessment--appropriate active substance. For the selection of the correct active substance, the following criteria are named: self-security in the counselling, first-hand experiences as well as the wish of the customer. At the same time, it is striking that the most frequent critique the pharmacy staff gets from pharmacy customers is the lack of effectiveness of the selected medication. With that in mind, it is possible that not the appropriate medication was selected, and the chosen criteria as selection method should be replaced by an evidence-based decision. Secondly, the results show that in up to 52% of the cases, depending on the indications, the participating consultants felt less certain to uncertain with regards to possible interactions or contraindications. Also in this context, it is desirable to prepare the existing data in such a practical way, that the

  20. 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.

  1. 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.

  2. 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.

  3. 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°.

  4. 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.

  5. 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

  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. 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...

  8. 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...

  9. SMV model-based safety analysis of software requirements

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Kwang Yong [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Seong, Poong Hyun [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)], E-mail: phseong@kaist.ac.kr

    2009-02-15

    Fault tree analysis (FTA) is one of the most frequently applied safety analysis techniques when developing safety-critical industrial systems such as software-based emergency shutdown systems of nuclear power plants and has been used for safety analysis of software requirements in the nuclear industry. However, the conventional method for safety analysis of software requirements has several problems in terms of correctness and efficiency; the fault tree generated from natural language specifications may contain flaws or errors while the manual work of safety verification is very labor-intensive and time-consuming. In this paper, we propose a new approach to resolve problems of the conventional method; we generate a fault tree from a symbolic model verifier (SMV) model, not from natural language specifications, and verify safety properties automatically, not manually, by a model checker SMV. To demonstrate the feasibility of this approach, we applied it to shutdown system 2 (SDS2) of Wolsong nuclear power plant (NPP). In spite of subtle ambiguities present in the approach, the results of this case study demonstrate its overall feasibility and effectiveness.

  10. Exploring Children's Requirements for Game-Based Learning Environments

    Directory of Open Access Journals (Sweden)

    Marja Kankaanranta

    2008-08-01

    Full Text Available End users' expertise in the development of new applications is acknowledged in user-centered and participatory design. Similarly, children's experience of what they find enjoyable and how they learn is a valuable source of inspiration for the design of products intended for them. In this paper, we explore experiences obtained from collaboration with elementary school children in the design of learning environments, based on three projects and three requirements gathering techniques. We also discuss how the children experienced the participation. The children's contribution yielded useful, both expected and unanticipated, outcomes in regard to the user interface and contents of the learning environments under development. Moreover, we present issues related to design collaboration with children, especially in terms of the children's feeling of ownership over the final outcome.

  11. 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.

  12. 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。

  13. 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

  14. 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.

  15. 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

  16. 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。

  17. FINITE ELEMENT NUMERICAL SIMULATION OF BOLT CONNECTION%钢结构螺栓连接的有限元数值模拟

    Institute of Scientific and Technical Information of China (English)

    王智

    2013-01-01

    螺栓连接是钢结构连接的主要方式之一,具有施工简单、拆装方便等优点.现行钢结构规范中对螺栓连接的计算都是在一定的假设条件下进行的.本文以钢结构规范中的计算公式为基础,运用有限元数值分析的方法,采用ABAQUS来分析普通螺栓群在受剪和受拉条件下的各个螺栓的受力情况.将有限元软件模拟的结果与公式计算结果进行比较,证明规范公式的正确性.文中分别模拟分析了普通螺栓群在受剪的情况下承受轴心力、扭矩,和普通螺栓群在受拉的情况下承受拉力、弯矩的受力情况.%The bolt connection as one of the main ways of steel connection, has advantages of simple construction, easy demolition and so on. The calculation of bolt connection is in a certain hypothesis conditions in the current code. This article is based on calculation formulas included in code for design of steel structures, it is adopted that finite element analysis method and the software ABAQUS to analyse the behaviours of the ordinary bolt group which are in shear and tensile conditions. Then, the simulation results and the outcome calculated by formulas are compared in order to prove the correctness of the formulas of the code. The paper analyses the behaviours of the bolt group in the case of bearing shear force and torque. At the same time , it is also analysed that the behaviours of the bolt group in the case of tension and moment

  18. 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...

  19. Thermal conductance measurements of bolted copper joints for SuperCDMS

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, R.; Tatkowski, Greg; Ruschman, M.; Golwala, S. R.; Kellaris, N.; Daal, M.; Hall, Jeter C.; Hoppe, Eric W.

    2015-09-01

    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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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。

  5. 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.

  6. The strength of glued-in bolts after 9 years in situ loading. An investigation of fatigue loaded glued-in bolts from the blade-to-hub connection of the Nibe Windmill-B

    Energy Technology Data Exchange (ETDEWEB)

    Uhre Pedersen, M.; Clorius, C.O.

    1995-07-01

    In 1993 one of the three 2.5 t blades from the 20 m radius rotor of the Nibe-B windmill was struck by lightning and subsequently dismounted. The blades had a solid leading edge of glulam and each blade was connected to the hub by 28 glued-in bolts arranged circumferentially in the root section. The mishap offered a unique opportunity to investigate the residual strength of the glued-in bolts after 9 years of oscillating load including a total of 5.0 10{sup 7} cycles. The bolts investigated have a hollow tapering. This geometry was developed at the Department of Structural Engineering and has been reported to give a 20% higher load bearing capacity than similar solid bolts. The holes in the glulam were 2 mm oversized and an epoxy glue was used to bond the shot blasted bolts to the glulam. A test specimen was cut from the root section of one blade. This produced a 0.8 m high solid glulam cylinder with a diameter of 0.86 m containing the 28 glued-in bolts. A 500 kN servo hydraulic double acting actuator delivered the pull-out force at the circumferential position of the bolts, and a hydraulic press delivered a counter force at the centre of the test specimen. The displacement of the actuator piston was used to control the pull-out tests. The time from test start to bolt failure was approximately 4 minutes. A total of 11 bolts were pulled out between undamaged bolts. The mean strength of these bolts was found to be 362 kN with a standard deviation of 37 kN. When comparing this mean residual strength with previously recorded test data a 5% strength reduction was observed. The force displacement curves showed no plastic capacity in the connections. A displacement between 0.4 mm and 1.0 mm was observed at fracture. The bolts pulled out between failed bolts showed a surprisingly high mean residual strength of 304 kN. (EG) 14 refs.

  7. 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

  8. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kopsaftopoulos, Fotis P; Fassois, Spilios D, E-mail: fkopsaf@mech.upatras.gr, E-mail: fassois@mech.upatras.gr [Stochastic Mechanical Systems and Automation (SMSA) Laboratory Department of Mechanical and Aeronautical Engineering University of Patras, GR 265 00 Patras (Greece)

    2011-07-19

    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.

  10. 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.

  11. 某600 MW燃煤发电机组调门螺栓理化性能检验%Physical and Chemical Test of Valve Bolts of a 600 MW Coal-fired Power Generating Unit

    Institute of Scientific and Technical Information of China (English)

    王家庆

    2016-01-01

    对某600 MW燃煤发电机组3根高调门螺栓和2根中调门螺栓(螺栓材料为R26合金)进行了化学成分分析、力学性能试验和金相检验。结果表明:5根螺栓材料化学成分均符合标准技术要求,其中3根高调门螺栓的硬度高于标准要求,且显微组织中存在标准中不允许出现的带状组织;2根中调门螺栓的力学性能满足标准要求,显微组织正常。螺栓中碳氮化物和金属间化合物呈带状分布会割裂基体,影响材料的高温持久强度,对设备的安全运行构成隐患。%Chemical composition analysis, mechanical property test and metallographic examination of three governor valve bolts and two intermediate pressure valve bolts of a 600 MW coal-fired power generating unit,were conducted.The results show that the chemical compositions of all the five bolts met the requirements of relevant standard, while the hardness of the three governor valve bolts was higher than the required value and there was banded structure which was not allowed in the microstructure.The mechanical properties of the two intermediate pressure valve bolts met the requirements of relevant standard,and the microstucture was normal.The carbon nitride and the intermetallic compound distributed in band in the bolts could cut apart the metal matrix,affect the high temperature creep rupture strength of the material and become a hidden danger to the safety operation of the unit.

  12. 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.

  13. 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.

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

    OpenAIRE

    Carlos E. Otero; Abdel Ejniou; L. Daniel Otero; Abrar Qureshi

    2012-01-01

    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 suitabil...

  15. 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.

  16. 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

  17. 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...

  18. Secondary skull fractures in head wounds inflicted by captive bolt guns: autopsy findings and experimental simulation.

    Science.gov (United States)

    Perdekamp, Markus Grosse; Kneubuehl, Beat P; Ishikawa, Takaki; Nadjem, Hadi; Kromeier, Jan; Pollak, Stefan; Thierauf, Annette

    2010-11-01

    Apart from one article published by Rabl and Sigrist in 1992 (Rechtsmedizin 2:156-158), there are no further reports on secondary skull fractures in shots from captive bolt guns. Up to now, the pertinent literature places particular emphasis on the absence of indirect lesions away from the impact point, when dealing with the wounding capacity of slaughterer's guns. The recent observation of two suicidal head injuries accompanied by skull fractures far away from the bolt's path gave occasion to experimental studies using simulants (glycerin soap, balls from gelatin) and skull–brain models. As far as ballistic soap was concerned, the dimensions of the bolt's channel were assessed by multi-slice computed tomography before cutting the blocks open. The test shots to gelatin balls and to skull-brain models were documented by means of a high-speed motion camera. As expected, the typical temporary cavity effect of bullets fired from conventional guns could not be observed when captive bolt stunners were discharged. Nevertheless, the visualized transfer of kinetic energy justifies the assumption that the secondary fractures seen in thin parts of the skull were caused by a hydraulic burst effect. PMID:20393855

  19. 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...

  20. 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)

  1. 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.

  2. An Investigation on Load Bearing Capacities of Cement and Resin Grouted Rock Bolts Installed in Weak Rocks

    Science.gov (United States)

    Kalyoncu Erguler, Guzide; Abiddin Erguler, Zeynal

    2015-04-01

    Rock bolts have been considered one of indispensable support method to improve load bearing capacity of many underground engineering projects, and thus, various types of them have been developed until now for different purposes. Although mechanically anchored rock bolts can be successfully installed to prevent structurally controlled instabilities in hard rocks, in comparison with cement and resin grouted rock bolts, these types of anchors are not so effective in weak rocks characterized by relatively low mechanical properties. In order to investigate the applicability and to measure relative performance of cement and resin grouted rock bolts into weak and heavily jointed rock mass, a research program mainly consisting of pull-out tests was performed in a metal mine in Turkey. The rock materials excavated in this underground mining were described as basalt, tuff, ore dominated volcanic rocks and dacite. To achieve more representative results for rock materials found in this mining and openings excavated in varied dimensions, the pull-out tests were conducted on rock bolts used in many different locations where more convergences were measured and deformation dependent instability was expected to cause greater engineering problems. It is well known that the capacity of rock bolts depends on the length, diameter and density of the bolt pattern, and so considering the thickness of plastic zone in the studied openings, the length and diameter of rock bolts were taken as 2.4 m. and 25 mm., respectively. The spacing between rows changed between 70 and 180 cm. In this study, totally twenty five pull-out tests were performed to have a general understanding about axial load bearing capacity and support reaction curves of cement and resin grouted rock bolts. When pull load-displacement curves belongs to cement and resin grouted rock bolts were compared with each other, it was determined that cement grouted rock bolts carry more load ranging between 115.6 kN and 127.5 kN with

  3. Distribution of Stress on Bonded Length of Tension-type Rock Bolt Based on Theory of Elasticity%基于弹性理论的拉力型锚杆锚固段应力分布规律研究

    Institute of Scientific and Technical Information of China (English)

    彭辉; 袁超; 向德强

    2013-01-01

    视锚杆和周围介质为弹性材料,在弹性半空间里,利用Mindlin位移解,根据拉力型锚杆实际工作状态,推导出拉力型锚杆锚固段轴向应力和弹性粘结应力分布的方程。并分析相关岩土参数对锚固段轴向应力和剪应力的分布的影响,得出影响较大的几个因素,为拉力杆的力学分析和工程设计提供理论依据。%This research provides a theoretical basis for the pull rod mechanics analysis and en-gineering design. In accordance with the above,we can analyse related geotechnical parameters on the axial stress and shear stress distribution of the anchorage segment,and influence of sev-eral factors can be concluded. According to tensile type anchor rod under the actual working condition,we can deduce the equation about the distribution of axial stress and elastic bond stress of tensile type anchor's anchoring section when the anchor bolt and the surrounding me-dium are elastic materials by Mindlin's displacement solution in elastic half-space.

  4. 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.

  5. Bacterial artificial chromosome-derived molecular markers for early bolting in sugar beet.

    Science.gov (United States)

    Gaafar, R M; Hohmann, U; Jung, C

    2005-04-01

    Early bolting in sugar beet (Beta vulgaris L.) is controlled by the dominant gene B. From an incomplete physical map around the B gene, 18 bacterial artificial chromosomes (BACs) were selected for marker development. Three BACs were shotgun-sequenced, and 61 open reading frames (ORFs) were identified. Together with 104 BAC ends from 54 BACs, a total number of 55,464 nucleotides were sequenced. Of these, 37 BAC ends and 12 ORFs were selected for marker development. Thirty-one percent of the sequences were found to be single copy and 24%, low copy. From these sequences, 15 markers from ten different BACs were developed. Ten polymorphisms were determined by simple agarose gel electrophoresis of either restricted or non-restricted PCR products. Another five markers were determined by tetra-primer amplification refractory mutation system-PCR. In order to select candidate BACs for cloning the gene, genetic linkage between seven markers and the bolting gene was calculated using 1,617 plants from an F2 population segregating for early bolting. The recombination values ranged between 0.0033 and 0.0201. In addition, a set of 41 wild and cultivated Beta accessions differing in their early bolting character was genotyped with seven markers. A common haplotype encompassing two marker loci and the b allele was found in all sugar beet varieties, indicating complete linkage disequilibrium between these loci. This suggests that the bolting gene is located in close vicinity to these markers, and the corresponding BACs can be used for cloning the gene.

  6. 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.

  7. A transformation approach for collaboration based requirement models

    CERN Document Server

    Harbouche, Ahmed; Mokhtari, Aicha

    2012-01-01

    Distributed software engineering is widely recognized as a complex task. Among the inherent complexities is the process of obtaining a system design from its global requirement specification. This paper deals with such transformation process and suggests an approach to derive the behavior of a given system components, in the form of distributed Finite State Machines, from the global system requirements, in the form of an augmented UML Activity Diagrams notation. The process of the suggested approach is summarized in three steps: the definition of the appropriate source Meta-Model (requirements Meta-Model), the definition of the target Design Meta-Model and the definition of the rules to govern the transformation during the derivation process. The derivation process transforms the global system requirements described as UML diagram activities (extended with collaborations) to system roles behaviors represented as UML finite state machines. The approach is implemented using Atlas Transformation Language (ATL).

  8. 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...

  9. Towards Value-Based requirements prioritization for software product management

    OpenAIRE

    Samer I. Mohamed; Islam A. M. ElMaddah; Ayman M. Wahba

    2008-01-01

    Meeting stakeholders' requirements and expectations becomes one of the critical aspects on which any software organization in market-driven environment focuses on, and pays a lot of effort and expenses to maximize the satisfaction of their stakeholders. Therefore identifying the software product release contents becomes one of the critical decisions for software product success. Requirements prioritization refers to that activity through which product releases contents that maximize stakehold...

  10. 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.

  11. 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.

  12. A TRANSFORMATION APPROACH FOR COLLABORATION BASED REQUIREMENT MODELS

    Directory of Open Access Journals (Sweden)

    Ahmed Harbouche

    2012-02-01

    Full Text Available Distributed software engineering is widely recognized as a complex task. Among the inherent complexitiesis the process of obtaining a system design from its global requirement specification. This paper deals withsuch transformation process and suggests an approach to derive the behavior of a given systemcomponents, in the form of distributed Finite State Machines, from the global system requirements, in theform of an augmented UML Activity Diagrams notation. The process of the suggested approach issummarized in three steps: the definition of the appropriate source Meta-Model (requirements Meta-Model, the definition of the target Design Meta-Model and the definition of the rules to govern thetransformation during the derivation process. The derivation process transforms the global systemrequirements described as UML diagram activities (extended with collaborations to system rolesbehaviors represented as UML finite state machines. The approach is implemented using AtlasTransformation Language (ATL.

  13. Value-based Requirements Engineering for Value Webs

    NARCIS (Netherlands)

    Zarvić, Novica; Daneva, Maya; Wieringa, Roel; Sawyer, P.; Paech, B.; Heymans, P.

    2007-01-01

    Since the 1980s, requirements engineering (RE) for information systems has been performed in practice using techniques (rather than the full method) from Information Engineering (IE) such as business goal analysis, function{ and process modeling, and cluster analysis. Recently, these techniques have

  14. ERP services effort estimation strategies based on early requirements

    NARCIS (Netherlands)

    Erasmus, Pierre; Daneva, Maya; Kalenborg, Axel; Trapp, Marcus

    2015-01-01

    ERP clients and vendors necessarily estimate their project interventions at a very early stage, before the full requirements to an ERP solution are known and often before a contract is finalized between a vendor/ consulting company and a client. ERP project estimation at the stage of early requireme

  15. Distribution of shear stress on resin bolt of anchoring rods and its damage model analysis%树脂锚杆锚固段剪应力分布及其损伤模式分析

    Institute of Scientific and Technical Information of China (English)

    李青锋; 易厚; 朱川曲

    2016-01-01

    为了分析树脂锚杆锚固段剪应力分布及其承载、损伤机理,提高树脂锚杆支护在煤矿现场应用的有效性,首先根据煤矿树脂锚杆的围岩环境和受力特点,基于集中载荷作用于半无限体表面和无限体内部的弹性力学解得到了树脂锚杆在非锚固段围岩破碎和完整时的锚固段锚固界面剪应力计算式,分析了锚杆杆体拉力在锚固段锚固界面的剪应力形成机理;然后采用FLAC数值模拟软件模拟了树脂锚杆锚固段的承载及变形,得到了树脂锚杆在一定载荷和围压作用下锚固界面塑性发展趋势;最后以混凝土试块模拟围岩,并在混凝土试块预留孔中锚固了树脂锚杆进行实验室拉拔试验,得到了树脂锚杆锚固段剪应力分布及其增加趋势.结果表明,树脂锚杆剪应力开始时呈负指数形态分布,随着锚杆拉应力的增大,锚固起始端剪切破坏剪应力降低,无围压时峰值剪应力迅速向较深部锚固界面移动并锚固失效,有围压时锚固界面在锚固起始端剪切破坏后仍有较大的锚杆拉应力发展范围.%In order to analysis the distribution, loading and damage mechanism of resin anchoring bolt anchorage shear stress, and to improve the effectiveness of the application of resin bolt support in coal mine field. According to the surrounding environment and the mechanical characteristics of resin anchoring bolt in coal mine , based on the elastic mechanics solution of concentrates on load ACTS on the surface of semi-infinite body and infinite internal body, that of shear stress calculation formula of anchorage, resin anchoring bolt in the anchoring of surrounding broken and full of the anchoring interface, was gotten and then shear stress formation mechanism, that of the anchor rod body tension in the interface of anchoring anchorage, was analysized; By using the FLAC numerical simulation software to simulate the bearing and deformation of resin anchoring bolt

  16. 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.

  17. CBASeRA: A Compiler Based Approach towards Semantic Requirements Analysis

    Directory of Open Access Journals (Sweden)

    Atifa Rafique

    2012-05-01

    Full Text Available Requirements Engineering (RE becomes one of an important aspect in Software Development Life Cycle (SDLC. To improve the overall process of requirements engineering, different techniques, models and practices are available. Semantic based requirements analysis and verification is one of the techniques to improve the overall quality of software. A new methodology is proposed for semantic based requirement analysis and verification which practices compiler based approach. Lexical Analyzer highlights ontologies from each requirement specification, described in natural language. During Ontologies Recognizer, the relationships and entities are extracted by acknowledging ontologies. Now by applying SQL commands on ontologies (entities and relationships, we form Requirements Knowledge Base. Tree Based Semantic Analyzer constructs a well-structured tree of entities and relationship. Semantic application on this tree presents the requirements in unambiguous form. In order to remove the ambiguities, the process of semantic based requirements analysis and verification is described with a case study.

  18. 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

  19. 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

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

    DEFF Research Database (Denmark)

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

    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...... 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......, which perhaps explains the increasing popularity of scenario analysis in business and other organizations. An institutionalised usage of scenario planning can shape a company's ability to act rather than to react in a volatile environment. Emerging weak signals (i.e. indicators of change) can...

  1. 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...

  2. 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...

  3. 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.

  4. 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.

  5. 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

  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. 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.

  8. 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

  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. 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.

  11. 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.

  12. 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.

  13. 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...

  14. 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.

  15. 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

  16. Assessment of Performance-based Requirements for Structural Design

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2005-01-01

    The paper presents how actions can be assessed for a performance-based structural fire safety design from the first formulations in the building program to the final derivations of the fire load to be applied for each structural member. In order to indicate what is of importance for the assessment...

  17. 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

  18. Cause Analysis and Improvement of Fracture Bolts on the Pipe Plate of Floating Head Type Heat Exchanger%浮头式热交换器浮头管板螺栓断裂原因分析及改进

    Institute of Scientific and Technical Information of China (English)

    陈彩霞; 赵青

    2014-01-01

    通过扫描电镜观察、硬度测试、化学成分分析及金相检验等方法分析了浮头式热交换器浮头管板连接螺栓的断裂失效原因。结果表明,硫化物应力腐蚀开裂、氢致开裂和螺纹加工产生应力集中、材料硬度不满足湿硫化氢介质中的使用要求是螺栓断裂的主要原因。%Fracture analysis of the bolts on the pipe plate of floating head type heat exchanger was conducted by means of scanning electron microscopy (SEM ) ,energy dispersive spectrometer (EDS) ,hardness test ,chemical analysis and metallographic examination etc .The results showed that the sulfide stress corrosion cracking (SSCC ) and hydrogen induced cracking (HIC ) is the main reason for the bolts fracture .The thread processing stress concentration ,the mismatch be-tween the H2 S medium on the material hardness requirements and the used material finally caused the bolts fracture .

  19. 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.)

  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. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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...

  6. 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.

  7. 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.

  8. 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...

  9. 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。

  10. Trust and Privacy Solutions Based on Holistic Service Requirements.

    Science.gov (United States)

    Sánchez Alcón, José Antonio; López, Lourdes; Martínez, José-Fernán; Rubio Cifuentes, Gregorio

    2015-12-24

    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.

  11. 螺栓组拧紧顺序对结构体接触刚度的影响研究%Research on Influence of Contact Stiffness of Bolted Assembly Structure from Bolt-up Sequence

    Institute of Scientific and Technical Information of China (English)

    李培林; 王庆力; 王崴; 刘晓卫

    2014-01-01

    针对螺栓连接结构体接触刚度受拧紧顺序影响机理研究存在的不足,首先建立了单螺栓拧紧扭矩T与结合面刚度K的关联模型;然后在ANSYS中仿真分析了不同拧紧顺序下结合面模态频率特征,根据频率f与结合面刚度K之间的映射关系,进而得出最佳拧紧顺序;最后利用实验进行验证。结果表明,不同拧紧顺序结合面等效刚度K不同,结构的一阶固有频率也随之改变,同时拧紧最优、对角拧紧次之、顺序拧紧最差,说明拧紧顺序与固有频率之间存在着非线性关系。仿真分析与测试得到的一阶模态频率间的误差较小,证明了该建模方法能够有效分析拧紧顺序对结合面动力学性能的影响。%According to the existence problems of study on the mechanism of contact stiffness of bolted as-sembly structure formed by tightening sequence ( TS ) , a TK model of single bolt structure is established;then the frequency characteristics of combined surface under different TS was analyzed by using ANSYS;the optimal TS is obtained based on the frequency and the interface stiffness mapping. At last, a group of experiments was done to verify the above conclusions. The results show that the interface stiffness is verify under different TS, and so does the first rank natural frequency of the structure;the nonlinear response of the structure is significantly affected by TS that tighten at the same time is the optimal method compared with other TS. A small error of modal frequency between simulating and testing proves that the modeling method can effectively analyze impacts of the TS on the dynamic properties of the interface.

  12. 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

  13. 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

  14. The Calculation of Material Requirements Based on BOP in Assembly Production

    Institute of Scientific and Technical Information of China (English)

    ZENG Hong-xin; BIN Hong-zan

    2005-01-01

    A calculation method for material requirements which is based on BOP( Bill of Process) in assembly production is presented in this paper. Firstly, the BOP of assembly production is constructed.Then, the calculation method Based on the BOP is brought forward for material requirements planning.

  15. 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. 956.4 Section 956.4 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOME LOAN BANK ASSETS AND OFF-BALANCE SHEET ITEMS FEDERAL HOME LOAN BANK INVESTMENTS § 956.4 Risk-based capital requirement...

  16. 42 CFR 488.68 - State Agency responsibilities for OASIS collection and data base requirements.

    Science.gov (United States)

    2010-10-01

    ... 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 or... data; (2) Conduct basic system management activities including hardware and software...

  17. 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

  18. 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.

  19. 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.

  20. Nuts and Bolts - Techniques for Genesis Sample Curation

    Science.gov (United States)

    Burkett, Patti J.; Rodriquez, M. C.; Allton, J. H.

    2011-01-01

    The Genesis curation staff at NASA Johnson Space Center provides samples and data for analysis to the scientific community, following allocation approval by the Genesis Oversight Committee, a sub-committee of CAPTEM (Curation Analysis Planning Team for Extraterrestrial Materials). We are often asked by investigators within the scientific community how we choose samples to best fit the requirements of the request. Here we will demonstrate our techniques for characterizing samples and satisfying allocation requests. Even with a systematic approach, every allocation is unique. We are also providing updated status of the cataloging and characterization of solar wind collectors as of January 2011. The collection consists of 3721 inventoried samples consisting of a single fragment, or multiple fragments containerized or pressed between post-it notes, jars or vials of various sizes.

  1. 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

  2. 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"

  3. A prediction model of IASCC initiation stress for bolts in PWR core internals

    Energy Technology Data Exchange (ETDEWEB)

    Fukuya, Koji, E-mail: fukuya@inss.co.j [Institute of Nuclear Safety System, 64 Sata, Mihama, Mikata, Fukui 919-1205 (Japan); Fujii, Katsuhiko; Nishioka, Hiromasa [Institute of Nuclear Safety System, 64 Sata, Mihama, Mikata, Fukui 919-1205 (Japan); Takakura, Kenichi; Nakata, Kiyotomo [Japan Nuclear Energy Safety Organization, 3-17-1 Toranomon, Minato, Tokyo 105-0001 (Japan)

    2010-03-15

    A model of IASCC initiation stress for bolts of core internals in pressurized water reactors was developed considering differences in material property changes due to irradiation and material conditions. Assuming that IASCC initiation was controlled by grain boundary composition and yield strength, these values for each specimen of post-irradiation IASCC initiation tests were calculated by physical kinetic models considering dose rate, temperature, material composition and surface hardening. Then, correlations of grain boundary composition and yield strength with IASCC initiation stress were determined. The model predicted that the IASCC initiation stress became lower with dose and was lower for higher temperature, lower flux and higher surface hardening level.

  4. 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%...

  5. 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

  6. 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...

  7. Round timber bolted joints reinforced with modified washers and self-drilling screws

    Directory of Open Access Journals (Sweden)

    Antonín Lokaj

    2016-03-01

    Full Text Available Timber constructions made of round timber components are becoming more and more popular. Given that in the current European standards for the design of timber structures, timber-to-timber joint type is solved only for squared timber. This paper presents results of static tests in tension at an angle of 0°, 90°, 60° to the grain of round timber bolted joints. This research looks into reinforcement with modified washers or self-drilling screws, as these are the least labour-intensive (while economically advantageous. The joints samples were experimentally tested in the laboratory of the Faculty of Civil Engineering VŠB TU Ostrava.

  8. Numerical and experimental analysis on load sharing & optimization of the joint parameters of polymer composite multi bolted joints

    Science.gov (United States)

    Latha Shankar, B.; Sudeep Kumar, T.; Shiva Shankar, G. S.

    2016-09-01

    In the present work, the bearing failure of composite bolted connections of composite laminates was analysed both experimentally and numerically. The glass fiber woven mat 600GSM/ epoxy composite laminates were prepared using wet-layup technique. The process parameters were taken care during preparation of laminates. Examination is done for various estimations of edge-to-hole diameter and width-to-hole diameter proportion. Stress is evaluated in laminates by utilizing Hart-Smith criteria. Ideal estimation of e/d proportion, d/w proportion is recommended for most extreme effectiveness. A numerical technique is utilized for the rough determination of a load shared by bolts in a numerous "bolted" joints loaded in tension were investigated experimentally and numerically. The effect of un-evenness in load shearing is suggested.

  9. 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

  10. 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...

  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. 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.

  13. 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.

  14. 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 ...

  15. 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.

  16. Development of elastomeric isolators to reduce roof bolting machine drilling noise

    Science.gov (United States)

    Michael, Robert; Yantek, David; Johnson, David; Ferro, Ernie; Swope, Chad

    2015-01-01

    Among underground coal miners, hearing loss remains one of the most common occupational illnesses. In response to this problem, the National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) conducts research to reduce the noise emission of underground coal-mining equipment, an example of which is a roof bolting machine. Field studies show that, on average, drilling noise is the most significant contributor to a roof bolting machine operator’s noise exposure. NIOSH OMSHR has determined that the drill steel and chuck are the dominant sources of drilling noise. NIOSH OMSHR, Corry Rubber Corporation, and Kennametal, Inc. have developed a bit isolator that breaks the steel-to-steel link between the drill bit and drill steel and a chuck isolator that breaks the mechanical connection between the drill steel and the chuck, thus reducing the noise radiated by the drill steel and chuck, and the noise exposure of the roof bolter operator. This paper documents the evolution of the bit isolator and chuck isolator including various alternative designs which may enhance performance. Laboratory testing confirms that production bit and chuck isolators reduce the A-weighted sound level generated during drilling by 3.7 to 6.6 dB. Finally, this paper summarizes results of a finite element analysis used to explore the key parameters of the drill bit isolator and chuck isolator to understand the impact these parameters have on noise. PMID:26568650

  17. 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.

  18. 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.

  19. 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

  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. 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.

  2. 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…

  3. Analyzing and studying factors for determining neutral point position of fully grouted rock bolt%全长注浆岩石锚杆中性点影响因素分析研究

    Institute of Scientific and Technical Information of China (English)

    朱训国; 杨庆

    2009-01-01

    The neutral point theory is the important theory in underground engineering reinforcement theory. At present, the formula to determine neutral point position has been existed some unreasonable place. The neutral point theory had been further consummated and improved on the foundation of pre-researchers. Base on the developed analytical model and the theory of frictional resistance is zero at the neutral point, the factors have been detailed analyzed for affecting the neutral point position; and the correlations have been gained which affecting neutral point position. Through analyzing, it is revealed that the hydrostatic primary stress, bolt length, bolt spacing having no influence to neutral point position, and the radius of tunnel, Young's moduli of rock and bolt, the bolt diameter having remarkable influence to it. Among them, it is linear relation among the radius of tunnel, the bolt diameter with the neutral point position, but it is exponential function relations among the Young's modulus of rock and bolt with the neutral point position. The relationship of Young's modulus of rock mass and neutral point position presents exponential decreasing; the relationship of -Young's modulus of bolt and neutral point position presents exponential increasing. Through the factors analyzed, it has obtained that the general functional between the neutral point position and the correlation parameter, for further to study the neutral point theory providing the certain reference significance.%中性点理论是地下工程锚固理论中的重要理论,但目前对于中性点位置的确定计算公式存在不合理之处.在前人工作的基础上,对中性点理论进行了完善和改进.在建立的锚杆解析本构模型的基础上,结合中性点理论中锚杆中性点位置处的摩阻力为0的思想,对影响中性点位置的因素进行了较详细的分析,得出了影响锚杆中性点位置的相关因素.通过分析研究得到,

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. Effect of parameters on local stress field in single-lap bolted joints with the interference fit

    Directory of Open Access Journals (Sweden)

    Jiefeng Jiang

    2016-05-01

    Full Text Available From the interference fit bolt installation to tensile loading stage in single-lap joint with a hi-lock bolt, the stress and strain fields were studied experimentally and numerically. A three-dimensional finite element model was generated to simulate the experimental setup, which was validated using the experimental data. The fatigue behavior of the bolted joint is influenced by the local stress fields on the faying surface near the holes in single-lap joints. Therefore, with the aim to improve design awareness, the effects of the parameters on the local stress fields were investigated by means of finite element simulation. With an increase in the interference fit size, the occurred position of the maximum stress values on the upper plate faying surface moves away from the hole edge gradually. As the clamping force or friction coefficient increases, the position of larger stress area is changed to the side of bearing load from the transverse direction. The lap geometry of the bolted joint as well as the amplitude of tensile load has apparent impact on the maximum stress value.

  10. 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

  11. 75 FR 79312 - Requirements for Fingerprint-Based Criminal History Records Checks for Individuals Seeking...

    Science.gov (United States)

    2010-12-20

    ... test reactor licensees to obtain a fingerprint- based criminal history records check before granting...; ] NUCLEAR REGULATORY COMMISSION 10 CFR Part 73 RIN 3150-AI25 Requirements for Fingerprint-Based Criminal History Records Checks for Individuals Seeking Unescorted Access to Research or Test Reactors...

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

    Science.gov (United States)

    2010-01-01

    ... losses as support for the credit risk of all AMA estimated by the Bank to represent a credit risk that is...) Recalculation of credit enhancement. For risk-based capital purposes, each Bank shall recalculate the estimated... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Risk-based capital requirement for...

  13. 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... adequacy consistent with the Basel Committee on Banking Supervision's “International Convergence of Capital... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Risk-Based Capital...

  14. 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

  15. 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.

  16. 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.

  17. Fracture failure analysis of driving bolts%驱动螺栓断裂失效分析

    Institute of Scientific and Technical Information of China (English)

    邓德伟; 张翠萍; 鲁俊

    2013-01-01

    Driving bolts made of 3Cr13 stainless steel was fractured during the service .Chemical composition , mechanical properties and microstructure of the failed bolt were analysed .The results show that the inappropriate heat treatment leads anormal microstructure to unquenched and untempered which result to the bolt failure .The microstructure is tempered martensites and undissolved carbides that lead to high microhardness .Additionally , globular nonmetallic inclusions and multidirectional cracks are also observed in the bolt and accelerated the failure when the bolt is suffered from a shock or a torsional load .%3 Cr13不锈钢驱动螺栓在服役一段时间后在螺纹处发生断裂,对其化学成分、力学性能、断口及显微组织进行观察和分析。结果表明,螺栓断裂主要是由于热处理工艺不当,导致螺栓最终服役状态并非调质态,显微组织为回火马氏体及未溶碳化物颗粒,螺栓整体硬度过高;另外,组织中存在链状及球状非金属夹杂物,螺纹部位也有多种取向的裂纹,因而螺栓在受到冲击或扭转载荷时,裂纹和非金属夹杂可能成为裂纹源,以致发生脆性断裂。

  18. 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...

  19. Respiratory clinical guidelines inform ward-based nurses’ clinical skills and knowledge required for evidence-based care

    OpenAIRE

    Alisha M. Johnson; SMITH, Sheree M.S.

    2016-01-01

    Respiratory clinical guidelines provide clinicians with evidence-based guidance for practice. ­Clinical guidelines also provide an opportunity to identify the knowledge and technical and non-technical skills required by respiratory ward-based registered nurses. The aim of this review was to use a systematic process to establish the core technical and non-technical skills and knowledge ­identified in evidence-based clinical guidelines that enable the care of hospitalised adult respiratory pati...

  20. 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

  1. 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....

  2. Extraction of Bolt Supporting Role%浅议锚杆支护技术

    Institute of Scientific and Technical Information of China (English)

    刁先锋

    2015-01-01

    In recent years, with the continuous development of coal mining technology, mining depth increase gradually. Mines and roadway support is an important guarantee of coal mine safety production. At present,which has been widely applied bolting. This article from the category,anchor supporting form,function and matters needing attention aspects in this paper,the personal views.%近几年来,随着煤矿开采技术的不断发展,开采深度逐步增加。矿井和巷道支护是煤矿安全生产的重要保证。目前,锚杆支护应用较为广泛。从锚杆类别、支护形式、作用、注意事项等方面阐述个人观点。

  3. Crystalline capsules: metal-organic frameworks locked by size-matching ligand bolts.

    Science.gov (United States)

    Wang, Hao; Xu, Jian; Zhang, Da-Shuai; Chen, Qiang; Wen, Rong-Mei; Chang, Ze; Bu, Xian-He

    2015-05-11

    Metal-organic frameworks (MOFs) are shown to be good examples of a new class of crystalline porous materials for guest encapsulation. Since the encapsulation/release of guest molecules in MOF hosts is a reversible process in nature, how to prevent the leaching of guests from the open pores with minimal and nondestructive modifications of the structure is a critical issue. To address this issue, we herein propose a novel strategy of encapsulating guests by introducing size-matching organic ligands as bolts to lock the pores of the MOFs through deliberately anchoring onto the open metal sites in the pores. Our proposed strategy provides a mechanical way to prevent the leaching of guests and thereby has less dependence on the specific chemical environment of the hosts, thus making it applicable for a wide variety of existing MOFs once the size-matching ligands are employed.

  4. 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

  5. Caveats: Numerical Requirements in Graph Theory Based Quantitation of Tissue Architecture

    Directory of Open Access Journals (Sweden)

    J. Sudbø

    2000-01-01

    Full Text Available Graph theory based methods represent one approach to an objective and reproducible structural analysis of tissue architecture. By these methods, neighborhood relations between a number of objects (e.g., cells are explored and inherent to these methods are therefore certain requirements as to the number of objects to be included in the analysis. However, the question of how many objects are required to achieve reproducible values in repeated computations of proposed structural features, has previously not been adressed specifically.

  6. 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.

  7. 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)

  8. 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.

  9. 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.

  10. A New Classification Analysis of Customer Requirement Information Based on Quantitative Standardization for Product Configuration

    Directory of Open Access Journals (Sweden)

    Zheng Xiao

    2016-01-01

    Full Text Available 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 information into quantifiable values would lead to a dynamic classification according to specific conditions and would enable an association with product configuration in an enterprise. This paper introduces a classification analysis based on quantitative standardization, which focuses on (i expressing customer requirement information mathematically and (ii classifying customer requirement information for product configuration purposes. Our classification analysis treated customer requirement information as follows: first, it was transformed into standardized values using mathematics, subsequent to which it was classified through calculating the dissimilarity with general customer requirement information related to the product family. Finally, a case study was used to demonstrate and validate the feasibility and effectiveness of the classification analysis.

  11. 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.

  12. 77 FR 23481 - State Program Requirements; Approval of Maine's Base National Pollutant Discharge Elimination...

    Science.gov (United States)

    2012-04-19

    ... FR 65052 (Nov. 18, 2003). This action generally authorized the state to administer the NPDES program... State to issue NPDES permits for all discharges within the Indian territories of the Penobscot Nation... AGENCY State Program Requirements; Approval of Maine's Base National Pollutant Discharge...

  13. 76 FR 29747 - State Program Requirements; Proposal To Approve Maine's Base National Pollutant Discharge...

    Science.gov (United States)

    2011-05-23

    ... 28, 2001. 66 FR 12791. As described in the Federal Register, EPA approved the state's application to... state to regulate cooling water intake structures under CWA section 316(b) (33 U.S.C. 1326(b)). 66 FR at... AGENCY State Program Requirements; Proposal To Approve Maine's Base National Pollutant...

  14. 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…

  15. Model-Based Requirements Analysis for Reactive Systems with UML Sequence Diagrams and Coloured Petri Nets

    DEFF Research Database (Denmark)

    Tjell, Simon; Lassen, Kristian Bisgaard

    2008-01-01

    of a derivative of UML 2.0 high-level Sequence Diagrams. The automated requirement checking is part of a bigger tool framework in which VDM++ is applied to automatically generate initial CPN models based on Problem Diagrams. These models are manually enhanced to provide behavioral descriptions of the environment...

  16. 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

  17. 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

  18. 胶合木外夹钢板群螺栓连接力学性能的试验研究%Experimental study on mechanics performance of multi-bolt steel-glulam-steel joints

    Institute of Scientific and Technical Information of China (English)

    徐德良; 刘伟庆; 刘子彤; 周叮

    2011-01-01

    采用8组40个连接试件,考察胶合木外夹钢板群螺检连接构件在顺纹受拉时的力学性能,探讨其破坏模式和受力机制.研究表明:胶合木外夹钢板群螺栓连接的破坏模式、承载力、刚度和延性与螺栓列数、每列的螺栓数、螺栓的布置方式有关;承载力不具有由螺栓数线性叠加的性质;螺栓总数不变、多列布置螺栓延性较佳.%The mechanics performance of multi-bolt steel-glulam-steel joints subjected to a load parallel to grain was investigated with 8 groups of 40 multi-bolt joints specimens. The failure mode and its mechanism were discussed. For multi-bolt steel-glulam-steel joints, results showed that the failure modes,bearing capacity , stiffness, and ductility were relevant to the rows of bolts, the number of bolts in a row and the way of bolts arranged. The bearing capacity of multi-bolt joints was nonlinear number of bolts. With the same number of bolts, the ductility of bolts arranged in multi-rows was better than that of one-row.

  19. 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

  20. Design of a requirements system for decommissioning of a nuclear power plant based on systems engineering

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hee Seong; Park, Seung Kook; Jin, Hyung Gon; Song, Chan Ho; Choi, Jong won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The nuclear industry has required an advanced system that can manage decommissioning information ever since the Korean government decide to decommission the Gori No.1 nuclear power plant. The D and D division at KAERI has been developing a system that can secure the reliability and sustainability of the decommissioning project based on the engineering system of the KRR-2 (Korean Research Reactor-2). To establish a decommissioning information system, a WBS that needs to be managed for the decommissioning of an NPP has been extracted, and requirements management research composed of system engineering technology has progressed. This paper propose a new type of system based on systems engineering technology. Even though a decommissioning engineering system was developed through the KRR-2, we are now developing an advanced decommissioning information system because it is not easy to apply this system to a commercial nuclear power plant. An NPP decommissioning is a project requiring a high degree of safety and economic feasibility. Therefore, we have to use a systematic project management at the initial phase of the decommissioning. An advanced system can manage the decommissioning information from preparation to remediation by applying a previous system to the systems engineering technology that has been widely used in large-scale government projects. The first phase of the system has progressed the requirements needed for a decommissioning project for a full life cycle. The defined requirements will be used in various types of documents during the decommissioning preparation phase.

  1. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

    Science.gov (United States)

    Chou, Ying-Chao; Yeh, Wen-Lin; Chao, Chien-Lin; Hsu, Yung-Heng; Yu, Yi-Hsun; Chen, Jan-Kan; Liu, Shih-Jung

    2016-01-01

    A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. PMID:27601901

  2. Enhancement of tendon-bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt.

    Science.gov (United States)

    Chou, Ying-Chao; Yeh, Wen-Lin; Chao, Chien-Lin; Hsu, Yung-Heng; Yu, Yi-Hsun; Chen, Jan-Kan; Liu, Shih-Jung

    2016-01-01

    A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon-bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon-bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon-bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon-bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. PMID:27601901

  3. 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.

  4. 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.

  5. Identification of RFLP markers closely linked to the bolting gene B and their significance for the study of the annual habit in beets (Beta vulgaris L.).

    Science.gov (United States)

    Boudry, P; Wieber, R; Saumitou-Laprade, P; Pillen, K; Van Dijk, H; Jung, C

    1994-08-01

    The annual habit in beet is due to complete or partial absence of the vernalization requirement and can cause severe problems in the beet crop. The absolute vernalization requirement in beet is controlled by a major geneB (bolting), known to be linked to the geneR (red hypocotyl color), in linkage group I. Segregation for theB andR genes was studied in several beet progenies. Penetrance of the annual habit inBb genotypes was affected by both environmental and genetic factors. The precise location in linkage group I of the major geneB was found by restriction fragment length polymorphism (RFLP) analysis in a back-cross progeny exhibiting partial penetrance of the annual habit. The linkage value betweenB andR was in good accordance with previous estimations. Use of the closest RFLP marker (pKP591: 3.8 recombination units) allowed us to estimate the penetrance of the annual habit in this back-cross as 0.62. Evidence of pseudo-compatibility was found in the wild coastal beet (Beta vulgaris sspmaritima) used as the mother plant of the back-cross: the selfing rate was estimated as 7%.

  6. 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

  7. 飞轮连接螺栓可靠性提升研究%Reliability Improvement Of Flywheel Connecting Bolt

    Institute of Scientific and Technical Information of China (English)

    栗明; 胡伟; 李广; 赵建永

    2016-01-01

    The flywheel and crankshaft is connected with the bolt of the flywheel,As flywheel connecting boltsis an important part of the transmission torque.If there is a problem of the flywheel connecting bolt fracture,is a great harm,it will cause the crank and the connecting parts to be declared worthless,cause serious economic losses. In order to ensure the reliability of the bolt connection,the following file will through the working condition、the influence of the EVB、driver’s driving habits、clutch matching specification、the bolts design to put forward corrective and preventive measures.%飞轮与曲轴采用飞轮连接螺栓进行联接,由于飞轮连接螺栓是传递力矩的重要部件,如果出现飞轮连接螺栓断裂的问题,危害性极大,会导致曲轴和曲轴连接件报废,造成严重的经济损失;为了确保螺栓联接的可靠性,文章从使用的工况、 EVB排气制动使用对发动机影响情况、用户驾驶习惯、离合器匹配规范、曲轴飞轮连接螺栓设计等方面提出整改预防措施。

  8. 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...

  9. Review of "System Modeling in Cellular Biology: From Concepts to Nuts and Bolts" by Szallasi, Stelling and Periwal

    OpenAIRE

    McSharry Patrick E

    2007-01-01

    Abstract "System Modeling in Cellular Biology: From Concepts to Nuts and Bolts" by Szallasi, Stelling and Periwal introduces the relevant concepts, terminology, and techniques of this field of science. It emphasises the modelling and computational challenges of taking a multidisciplinary approach to biology. This book provides a comprehensive introduction to systems biology and will form a valuable resource for students, teachers and researchers from both experimental and theoretical discipli...

  10. Tunneling by Mining Method:Lecture III:Anchor Bolts%漫谈矿山法隧道技术第三讲--锚杆

    Institute of Scientific and Technical Information of China (English)

    关宝树

    2016-01-01

    分析我国隧道锚杆支护技术中存在的主要问题,包括:1)没有实现商品化;2)多采用注浆式锚杆,没有针对不同的围岩条件采用不同的锚杆;3)不设垫板的锚杆比比皆是;4)锚杆功能单一;5)锚杆施工管理不到位。针对这些问题:1)重申了锚杆的功能;2)认为要实现锚杆的商品化,首先要求锚杆规格标准化,生产工厂化,介绍了英国的《锚杆技术标准》,指出我国也应着手编写《锚杆行业标准》,以利于锚杆商品化的实现,或者以一条新铁路线或以企业为试点设置锚杆制备厂;3)着重介绍了提高锚杆支护功能的措施———提高附着刚性和剪切刚性、提高锚固材料的充填饱满度、强化锚杆施工管理;4)介绍了几种新型锚杆的构造、规格、功能、优点、适用条件等,包括摩擦式锚杆(ZAM膨胀型锚杆、高承载力摩擦式锚杆、具有排水效果和注浆功能的锚杆)和纤维锚杆;5)介绍了发光型简易锚杆轴力计,并将其与通常的轴力量测进行对比,结果大致吻合。最后指出,锚杆的首要问题是加快工厂化(商业化)进程,编制了行业标准;提高锚杆支护效果要在锚固材料和围岩2方面下功夫;针对性地加强对摩擦式锚杆的研究及锚杆充填率评价方法的研究也应提到日程上来。%In this paper,the major limitations of application of anchor bolt to tunnel in China are analyzed,which mainly include:1)Non-industrialization of anchor bolt.2)Merely using grouting anchor bolt regardless of other types. 3)Gasket is not applied for anchor bolt.4)The anchor bolt function is simple.5 )Poor anchor bolt construction management system.In order to address these problems,the following issues are discussed:1)The anchor bolt function should be fully re-assessed.2)The anchor bolt should be standardized and the manufacturing of the anchor bolt should be

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. 胶合木钢夹板螺栓连接节点的抗火性能%Fire Resistance of Bolted Steel-Glulam-Steel Connections

    Institute of Scientific and Technical Information of China (English)

    张晋; 许清风; 柏益伟; 蔡建国

    2015-01-01

    为研究我国常用树种胶合木钢夹板螺栓连接节点的抗火性能,进行了4个胶合木钢夹板螺栓连接试件的炭化速度试验,以及两组(共8个)胶合木钢夹板螺栓连接试件在不同持荷水平下的耐火极限试验。结果表明:钢夹板边缘内侧区域木材的炭化速度小于钢夹板边缘外侧区域,不同截面的水平向炭化速度小于竖向炭化速度,炭化速度随着受火时间的延长有降低的趋势;试件端距达到规范要求后,将端距从7 d增加到10 d并不能明显提高耐火极限,耐火极限随着持荷水平的增加而明显降低;其他条件相同时,耐火极限试件升温快于炭化速度试件。%In order to reveal the fire resistance of bolted steel-glulam-steel connections using common tree species in China as the material , four connection specimens were tested to obtain the corresponding charring rates , and two groups of ( eight) specimens were tested to reveal their fire endurance in different load levels .It is found that (1) the charring rate of interior area at steel splint edge is lower than that of external area;(2) the horizontal charring rate is lower than the vertical one in different cross sections;(3) the charring rate tends to reduce with the prolon-ging of fire duration;(4) changing the end-to-end distance from 7d to 10d cannot remarkably improve the fire en-durance limit of the bolted connections when the distance meets the regulatory requirements ;(5) the fire endurance limit of the connections significantly decreases with the increase of load level;and (6) in the same conditions , the temperature rise of specimens in fire endurance tests is higher than that in charring rate tests .

  17. Risk-based requirements management framework with applications to assurance cases

    Science.gov (United States)

    Feng, D.; Eyster, C.

    The current regulatory approach for assuring device safety primarily focuses on compliance with prescriptive safety regulations and relevant safety standards. This approach, however, does not always lead to a safe system design even though safety regulations and standards have been met. In the medical device industry, several high profile recalls involving infusion pumps have prompted the regulatory agency to reconsider how device safety should be managed, reviewed and approved. An assurance case has been cited as a promising tool to address this growing concern. Assurance cases have been used in safety-critical systems for some time. Most assurance cases, if not all, in literature today are developed in an ad hoc fashion, independent from risk management and requirement development. An assurance case is a resource-intensive endeavor that requires additional effort and documentation from equipment manufacturers. Without a well-organized requirements infrastructure in place, such “ additional effort” can be substantial, to the point where the cost of adoption outweighs the benefit of adoption. In this paper, the authors present a Risk-Based Requirements and Assurance Management (RBRAM) methodology. The RBRAM is an elaborate framework that combines Risk-Based Requirements Management (RBRM) with assurance case methods. Such an integrated framework can help manufacturers leverage an existing risk management to present a comprehensive assurance case with minimal additional effort while providing a supplementary means to reexamine the integrity of the system design in terms of the mission objective. Although the example used is from the medical industry, the authors believe that the RBRAM methodology underlines the fundamental principle of risk management, and offers a simple, yet effective framework applicable to aerospace industry, perhaps, to any industry.

  18. 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

  19. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

    Directory of Open Access Journals (Sweden)

    Chou YC

    2016-08-01

    Full Text Available Ying-Chao Chou,1,2 Wen-Lin Yeh,2 Chien-Lin Chao,1 Yung-Heng Hsu,1,2 Yi-Hsun Yu,1,2 Jan-Kan Chen,3 Shih-Jung Liu1,2 1Department of Mechanical Engineering, Chang Gung University, 2Department of Orthopedic Surgery, Chang Gung Memorial Hospital, 3Department of Physiology and Pharmacology, Chang Gung University, Taoyuan, Taiwan Abstract: A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA bolt as the bone anchor and a poly(D,L-lactide-co-glycolide (PLGA nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. Keywords: polylactide–polyglycolide nanofibers, PLGA, collagen, 3D printing, polylactide, PLA, bone-anchoring bolts, tendon healing

  20. Automatically multi-paradigm requirements modeling and analyzing: An ontology-based approach

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    There are several purposes for modeling and analyzing the problem domain before starting the software requirements analysis. First, it focuses on the problem domain, so that the domain users could be involved easily. Secondly, a comprehensive description on the problem domain will advantage getting a comprehensive software requirements model. This paper proposes an ontology-based approach for mod-eling the problem domain. It interacts with the domain users by using terminology that they can under-stand and guides them to provide the relevant information. A multiple paradigm analysis approach, with the basis of the description on the problem domain, has also been presented. Three criteria, i.e. the ra-tionality of organization structure, the achievability of organization goals, and the feasibility of organiza-tion process, have been proposed. The results of the analysis could be used as feedbacks for guiding the domain users to provide further information on the problem domain. And those models on the problem domain could be a kind of document for the pre-requirements analysis phase. They also will be the basis for further software requirements modeling.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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...... of 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...

  7. 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.

  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. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 锚杆初始支护阻力的计算及预测%Calculation and prediction of initial support pressure in bolt support

    Institute of Scientific and Technical Information of China (English)

    王成; 杜泽生; 李志兵

    2012-01-01

    In order to get and predict initial support pressure,mechanical models of bolt’s stress and bolt’s installation were established,based on the hypothesis on surrounding rock of immediate bolt support in elastic-plastic status.The relationship between initial support pressure and tightening torque was analyzed,and theoretical solutions to initial support pressure were obtained for two contacts of pallet and nut.Meanwhile,verification research was carried out by "Bolt Force Transfer and Attenuating Test System".The results show that there is a linear relationship between initial support pressure and tightening torque under the same condition of bolt’s material quality,specification,row line space;when the tightening torque is among 0-300 N.m,the equations of initial support pressure and tightening torque is right;initial support pressure can be quantized and predicted by tightening torque.%为了便于计算和预测锚杆支护的初始支护阻力,基于锚杆及时支护时锚固区围岩处于弹塑性状态的假设,建立锚杆受力和安装力学模型,分析研究初始支护阻力与预紧力矩之间的关系,得出锚杆支护螺母、托盘两种接触类型的初始支护阻力的理论解,同时采用自制的"锚杆锚固传递及衰减规律"模拟试验台对初始支护阻力进行验证。研究结果表明:锚杆支护材质、规格及支护间排距相同时,其初始支护阻力与预紧力矩呈线性关系;预紧力矩在0-300 N.m时,初始支护阻力与预紧力矩间有准确的数学表达式,采用预紧力矩能够量化和预测初始支护阻力。

  14. 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.

  15. Failure Analysis on Fracture of Worm-gear Connecting Bolts%蜗轮连接螺栓断裂失效分析

    Institute of Scientific and Technical Information of China (English)

    王荣; 李玲

    2012-01-01

    装卸料机上的蜗轮连接螺栓材料为35钢,强度等级为10.9级,在设备运行大约10a后发生断裂。对断裂螺栓进行宏观、化学成分、硬度、金相、能谱和断口分析后得出,该螺栓的断裂性质为双向弯曲疲劳断裂,螺栓表面的脱碳和螺纹颈部的应力集中降低了该部位的疲劳性能。通过综合分析和螺栓受力估算后得出,螺栓断裂的主要原因是螺栓和内齿轮螺栓孔之间存在较大的间隙,使螺栓的受力状态和受力大小过早地发生了变化,造成连接螺栓疲劳断裂。%The worm-gear connecting bolts of refueling machines of a nuclear power plant,with material of 35 steel and strength grade of 10.9,fractured after the device running for about a decade,and means such as macro examination,chemical compositions analysis,hardness test,metallographic examination,fracture SEM analysis and so on,were used to analyze the fractured bolts.The results show that the fracture property of the bolts is two-way bending fatigue fracture.Surface decarburization of the bolts and stress concentration at the bolt thread neck decreased the fatigue strength,which resulted fatigue cracks formed here.By comprehensive analysis and force estimating,it was concluded that the main reason for the fracture is that there is a big gap between the bolt shank parts and their matching internal gear bolt holes,which made the force state and force size of the bolts changed early and finally resulted in fatigue fracture of the worm-gear connecting bolts.

  16. Design on the Transporting and Bolting Machine with Hopper and Two Arms%料斗式两臂运锚机的研制

    Institute of Scientific and Technical Information of China (English)

    马昭

    2014-01-01

    The transporting and bolting machine with hopper and two arms is a kind of equipment which is researched according to parallel working of the excavating and bolting integration on fully mechanized winning faces. It has the function of bolt supporting, materials transporting and self-driving. Its main structure, operation principle and service condition are introduced. It realizes reasonably connect of excavating, bolting and transporting work. The excavating and bolting efficiency is improved.%料斗式两臂运锚机是基于井下综掘工作面掘锚平行作业而研制的一种可进行锚杆支护和物料转运的具有自行走功能的运锚装备,本文详细介绍了该机的主要结构组成、工作原理以及使用情况,可实现掘锚运作业的合理衔接,提高了成巷效率。

  17. A web-based care-requiring client and Home Helper mutual support system.

    Science.gov (United States)

    Ogawa, Hidekuni; Yonezawa, Yoshiharu; Maki, Hiromichi; Hahn, Allen W; Caldwell, W Morton

    2005-01-01

    For the improved efficiency of home care of the elderly, a web-based system has been developed to enable faster communications between care-requiring clients, their Home Helper and the care manager. Changes to care items, such as cooking, bathing, washing, cleaning and shopping are usually requested by the elderly client over the telephone. However, the care central office often requires 24 hours to process and respond to such spoken requests. The system we have developed consists of Internet client computers with liquid crystal input tablets, wireless Internet Java enabled mobile phones and a central office server that yields almost instant communication. The care clients enter requests on the liquid crystal tablet at their home and then their computer sends these requests to the server at the Home Helper central office. The server automatically creates a new file of the requested items, and then immediately transfers them to the care manager and Home Helper's mobile phone. With this non-vocal and paperless system, the care-requiring clients, who can easily operate the liquid crystal tablet, can very quickly communicate their needed care change requests to their Home Helper.

  18. 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...

  19. 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...

  20. Regulation of bolting and identification of the α-tubulin gene family in Brassica rapa L. ssp pekinensis.

    Science.gov (United States)

    Zhang, Y W; Jin, D; Xu, C; Zhang, L; Guo, M H; Fang, Z Y

    2016-01-01

    Microtubules are important components of eukaryotic cells, and they play vital roles in cell morphogenesis, carrying of signaling molecules, transport of materials, and establishing the cell polarity. During bolting of biennial plants, cell division and elongation are involved, and cell elongation inevitably involves the microtubules arrangement and expression of related genes. So we deduce that it is of great significance to figure out the mechanism of bolting and flowering in which TUA genes are involved. In the present study, bioinformatic methods were used to predict and identify the α-tubulin gene family (BrTUAs) in Brassica rapa L. ssp pekinensis (Chinese cabbage) through the alignment of AtTUA gene sequence from Arabidopsis thaliana with the B. rapa genome database (http://brassicadb.org/brad/) using the basic local alignment search tool. The change in the structure and functions of BrTUAs during the process of evolution, cis-acting elements in the promoter sequences of BrTUAs, and the expression of the identified genes was also analyzed. Twelve members of the α-tubulin gene family were identified from Chinese cabbage. The gene length, intron, exon, and promoter regions were determined to have changed significantly during the genome evolution. Only five of the 12 members were encoded completely and were observed to differ in their spatial and temporal expression. The five BrTUA promoter sequences contained different numbers of cis-elements responsive to light and low-temperature response, cis-elements responsive among which hormonal responses were significantly different. We also report that the BrTUAs were involved in the regulation of the bolting in Chinese cabbage, and propose that this process could be controlled by regulating the expression of BrTUAs. PMID:26909938

  1. Discussion on Bolt Load of Lens Gasket Seal%透镜垫密封螺栓载荷的探讨

    Institute of Scientific and Technical Information of China (English)

    刘国振; 杨晓雨; 刘利云; 张建秀

    2015-01-01

    讨论了HG/T 20582—2011中透镜垫密封的螺栓载荷,并采用有限元方法对透镜垫螺栓载荷进行了分析,指出了螺栓载荷计算公式中存在的一些问题,并提出了新的计算公式,以供工程设计参考。%The bolt load of lens gasket seal in HG/T 20582—201 1 was discussed,and the bolt load was analyzed by the finite element method.Some problems on the calculated formula of the bolt load were pointed out.The new formula was presented for engineering design reference.

  2. Failure of intramedullary femoral nail with segmental breakage of distal locking bolts: a case report and re- view of the literature

    Directory of Open Access Journals (Sweden)

    Aggerwal Sameer

    2011-06-01

    Full Text Available 【Abstract】Breakage of locking bolts is an impor- tant 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 intramedul- lary 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 presenta- tion and discussed in detail the possible etiology of such a presentation and the management options when facing such a complex situation. Key words: Femoral fractures; Bone screws; Frac- ture fixation, intramedullary; Fracture healing

  3. [Regulatory requirements regarding cell-based medicinal products for human and veterinary use - a comparison].

    Science.gov (United States)

    Kuhlmann-Gottke, Johanna; Duchow, Karin

    2015-11-01

    At present, there is no separate regulatory framework for cell-based medicinal products (CBMP) for veterinary use at the European or German level. Current European and national regulations exclusively apply to the corresponding medicinal products for human use. An increasing number of requests for the regulatory classification of CBMP for veterinary use, such as allogeneic stem cell preparations and dendritic cell-based autologous tumour vaccines, and a rise in scientific advice for companies developing these products, illustrate the need for adequate legislation. Currently, advice is given and decisions are made on a case-by-case basis regarding the regulatory classification and authorisation requirements.Since some of the CBMP - in particular in the area of stem-cell products - are developed in parallel for human and veterinary use, there is an urgent need to create specific legal definitions, regulations, and guidelines for these complex innovative products in the veterinary sector as well. Otherwise, there is a risk that that the current legal grey area regarding veterinary medicinal products will impede therapeutic innovations in the long run. A harmonised EU-wide approach is desirable. Currently the European legislation on veterinary medicinal products is under revision. In this context, veterinary therapeutics based on allogeneic cells and tissues will be defined and regulated. Certainly, the legal framework does not have to be as comprehensive as for human CBMP; a leaner solution is conceivable, similar to the special provisions for advanced-therapy medicinal products laid down in the German Medicines Act.

  4. Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.)

    Institute of Scientific and Technical Information of China (English)

    Gui-xiao LA; Ping FANG; Yi-bo TENG; Ya-juan LI; Xian-yong LIN

    2009-01-01

    The effects of CO2 enrichment on the growth and glucosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassioa alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height,stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO2 concentration was elevated from 350 to 800 μl/L at each N concentration. In the edible part of the bolting stem,11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO2 concentration, N concentration, and CO2×N interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those of indolyl GSs were not affected, by elevated atmospheric CO2. However, at 20 mmol N/L,elevated CO2 had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO2 concentration in the three N treatments, resulting in changes in the C/N and N/S ratios.Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO2 concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO2 condition.

  5. E-Learning Based on Cloud Computing: Requirements, Challenges and Solutions

    Directory of Open Access Journals (Sweden)

    Alireza Mohammadrezaei

    2014-07-01

    Full Text Available Cloud Computing Technology has changed the access method and development of applications. This technology by providing necessary fundamentals runs applications as services on the net via web browsers. E-learning can utilize cloud computing in order to fulfill the required infrastructures and also to provide the improved performance, scalability, and increased availability. This study in addition to representation of concepts such as e-learning and cloud computing by utilizing descriptive-analytical approach investigates usage of cloud computing in e-learning. Also by introducing the advantages indicates the significance and the necessity of using e-learning based upon cloud computing. Ultimately, the challenges of this model and their solutions have been represented as well

  6. 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;

    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....

  7. Determining Loading Field based on Required Deformation for Isotropic Hardening Material

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Eringen's and Trusedell's polar decomposition are formulated by explicit formulation of displacement field, based on Chen's additive decomposition of deformation gradient. Then the strain introduced by the multiplicative decomposition and the strain introduced by the additive decomposition are formulated explicitly with displacement gradient. This formulation clears the intrinsic contents of strains defined by taking the Eringen's and Trusedell's polar decomposition. After that, Chen's strain definition was introduced to show that the plastic deformation can be understood as the irreversible local average rotation. For initial isotropic simple elastic material, the research shows that path-dependent feature of classical plasticity theory is naturally expressed in Chen's strain definition. For rate-independent plasticity, the related deformation stress was discussed. The research shows that for isotropic hardening material the relation equation between the required geometric configuration and the corresponding loading field is explicitly formulated. Hence, for metal forming, this paper explicitly formulates the related fields by displacement field and invariant elastic constants.

  8. 胶合木与胶合木螺栓连接力学性能试验研究%Experimental study of bolted glued timber-to-timber joints

    Institute of Scientific and Technical Information of China (English)

    徐德良; 刘伟庆; 周叮; 奚爱峰

    2011-01-01

    试验研究胶合木与胶合木单螺栓连接及群螺栓连接构件在顺纹受拉时的承载能力,分析其破坏模式和破坏机理,试验对象为3组9个单螺栓连接和4组20个群螺栓连接.研究表明:胶合木与胶合木单螺栓连接的力学性能与胶合木的厚度比有关,当侧材厚度比为4.375时,破坏形态Ⅲ型,延性最佳;胶合木与胶合木群螺栓连接的力学性能与螺栓列数及每列的螺栓数有关,群螺栓连接承载力应考虑螺栓的有效个数.两列布置群螺栓,破坏形态螺栓受力较均匀的两列开裂,其延性与一列与三列相比最佳.%Three groups of 9 single-bolted connections and four groups of 20 multi-bolted connections were tested to investigate their mechanical performance. The bearing capacity of single-bolted and multi-bolted glued timber-to-timber connections subjected to a load parallel to grain was studied. The failure modes and failure mechanism of bolted connections were discussed in detail. For the single-bolted glued timber-to-timber connections, it is shown that the failure modes, bearing capacity, stiffness and ductility are related to the thickness ratio of the side members of the structure. When the thickness ratio of the side member is equal to 4. 375, the failure modes is type M. In such a case, the ductility is the best. For multi-bolted timber-to-timber connections, it shows that the failure modes, bearing capacity, stiffness and ductility are relevant to the bolt number in a row and the row number of bolts. The bearing capacity of the joint is relevant to the effective number of bolts rather than the total number of bolts. In all of the multi-row arrangements, the two-row cracks failure mode where the bolts are uniformly loaded exhibits the highest ductility. Glued timber structure; single-bolt glued timber-to-timber connection; multi-bolt glued timber-to-timber

  9. 螺栓法兰金属垫片连接结构的紧密性分析方法%Method for Tightness Analysis of Bolted Flanged Connections with Metallic Gaskets

    Institute of Scientific and Technical Information of China (English)

    冯秀; 顾伯勤

    2011-01-01

    The design of the connections with metallic gaskets in the current codes is based on the gasket factors or the linear sealing stress,where the strength of elements is taken for design criterion,but the quantitative leakage and tightness are not taken into consideration. The method for the tightness analysis of bolted flanged connections with metallic gaskets was put forward based on the formula of the leakage rate, the analytical method for calculating the gasket contact stress and the load-deformation equation of connections. Analysis of examples shows that the leakage rate of connections can be reduced by increasing the gasket contact stress (I. E. Increasing bolt load) , which is not significant when the gasket contact stress is higher. The smoother surface of gaskets can be used for higher sealing of connections. Taking both the strength of elements and the maximal allowable leakage rate for design criterion,a new design method of bolted flanged connections may be developed.%现行金属垫片的设计以垫片系数或线密封比压为依据,主要针对法兰强度问题,而没有定量泄漏和紧密性的概念,因此无法从理论上说明连接是否紧密.在金属垫片变截面泄漏通道的泄漏率计算公式、接触应力分布的解析算法以及连接结构变形协调分析的基础上,建立连接系统的紧密性分析方法.实例分析表明:通过增加垫片应力(即提高螺栓载荷),可降低连接的泄漏率,但当垫片应力水平较高时,效果并不显著.对于密封性要求高的连接,可以采用表面较光滑的垫片.以最大允许泄漏率为设计准则的设计方法与以强度为设计准则的规范设计方法相结合,有可能发展成为一种新的密封连接设计方法.

  10. 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

  11. KEY TECHNIQUE TO COMPOSITELY SUPPORTING THE ROADWAY DRIVEN ALONG PREVIOUS GOAF WITH BOLTS,BARS AND CHAIN MESHES UNDER COMPLEX CONDTTIONS

    Institute of Scientific and Technical Information of China (English)

    HOUChaojiong; HEYanan; ZHANGYidong; GUANXuemao

    1995-01-01

    Large cross sectional roadways driven along the previous goaf are always in fragmental surrounding rocks, and remarkably deform under the influence of mining disturbance. It can successfully be supported by the composite bolt-bar-chain mesh support. However, success can only be achieved by getting hold of the key techniques as follows: rationally determining the size of the goaf-side rib, adopting bolts with extendible rod, determining rational parameters and strengthening the integral structure of the supporting system. These have proved effective and profitable by the practice at Dongpang colliery, Xingtai Coal Mining Administration. Hebei province,and are now in application there.

  12. Change Impact Analysis for SysML Requirements Models based on Semantics of Trace Relations

    NARCIS (Netherlands)

    Hove, ten David; Göknil, Arda; Kurtev, Ivan; Berg, van den Klaas; Goede, de Koos; Oldevik, J.; Olsen, G. K.; Neple, T.; Kolovos, D.

    2009-01-01

    Change impact analysis is one of the applications of requirements traceability in software engineering community. In this paper, we focus on requirements and requirements relations from traceability perspective. We provide formal definitions of the requirements relations in SysML for change impact a

  13. 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; Theorie de degradation du beton et developpement d'un nouveau modele d'endommagement en formulation incrementale tangente: calcul a la rupture applique au cas des chevilles de fixation ancrees dans le beton

    Energy Technology Data Exchange (ETDEWEB)

    Ung Quoc, H

    2003-12-15

    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

  14. Cylindrically guided wave technique for detection of stress corrosion cracking and corrosion wastage in long stud-bolts

    International Nuclear Information System (INIS)

    The authors discuss how, when performing an ultrasonic inspection of a cylindrical body, the sound waves, or pulses, will interact with the boundaries of the cylinder and produce mode-converted as well as normal longitudinal waves. The elastic energy of the wave propagating along the length of the cylinder is concentrated and produces strong echoes from shallow defects in the specimen. In threaded specimens, the guided wave produces signals from the threads that can be differentiated from defects in the cylinder. This paper reports on a study using the guided wave theory conducted to determine the optimum inspection transducer size and frequency relative to stud-bolt diameter and length. Bolts ranging from 25 to 285 cm (10 to 112 in.) in length and 2.5 to 11.5 cm (1 to 4.5 in.) in diameter were tested. For all cases, theoretical predictions agreed well with the experimental data. In this paper, the theory, experimental apparatus, and testing results are discussed

  15. Structural health monitoring for bolt loosening via a non-invasive vibro-haptics human-machine cooperative interface

    Science.gov (United States)

    Pekedis, Mahmut; Mascerañas, David; Turan, Gursoy; Ercan, Emre; Farrar, Charles R.; Yildiz, Hasan

    2015-08-01

    For the last two decades, developments in damage detection algorithms have greatly increased the potential for autonomous decisions about structural health. However, we are still struggling to build autonomous tools that can match the ability of a human to detect and localize the quantity of damage in structures. Therefore, there is a growing interest in merging the computational and cognitive concepts to improve the solution of structural health monitoring (SHM). The main object of this research is to apply the human-machine cooperative approach on a tower structure to detect damage. The cooperation approach includes haptic tools to create an appropriate collaboration between SHM sensor networks, statistical compression techniques and humans. Damage simulation in the structure is conducted by releasing some of the bolt loads. Accelerometers are bonded to various locations of the tower members to acquire the dynamic response of the structure. The obtained accelerometer results are encoded in three different ways to represent them as a haptic stimulus for the human subjects. Then, the participants are subjected to each of these stimuli to detect the bolt loosened damage in the tower. Results obtained from the human-machine cooperation demonstrate that the human subjects were able to recognize the damage with an accuracy of 88 ± 20.21% and response time of 5.87 ± 2.33 s. As a result, it is concluded that the currently developed human-machine cooperation SHM may provide a useful framework to interact with abstract entities such as data from a sensor network.

  16. Requirements of older adults for a daily use of an internet-based cognitive training platform.

    Science.gov (United States)

    Haesner, Marten; O'Sullivan, Julie L; Gövercin, Mehmet; Steinhagen-Thiessen, Elisabeth

    2015-03-01

    A decline of cognitive abilities is a part of normal human ageing. However, recent research has demonstrated that an enriched environment can have a beneficial impact on cognitive function in old age. Accordingly, mentally and socially active lifestyles are associated with less cognitive decline in old age. Specific interventions such as computerized cognitive training programs for older adults are also known to have a positive effect on the level of cognitive functioning. Therefore, online platforms combining cognitive training with web 2.0 features may yield multiple benefits for older users. However, to date only little research exists on technological acceptance and media use in this age-group especially for cognitively-impaired seniors. Therefore, in order to assess specific preferences and potential barriers of older adults regarding a web-based platform for cognitive training, we conducted qualitative interviews with 12 older adults. Half of the participants were diagnosed with mild cognitive impairment (MCI). Most importantly, our results show that cognitive exercises should incorporate themes and topics older adults are interested in. Additional communication features could serve as ideal methods for increasing user motivation. Furthermore, we derived eight critical requirements of older adults concerning daily use of a web-based cognitive training platform. Implications for future research and development are discussed.

  17. 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

  18. Memristive Hebbian plasticity model: device requirements for the emulation of Hebbian plasticity based on memristive devices.

    Science.gov (United States)

    Ziegler, Martin; Riggert, Christoph; Hansen, Mirko; Bartsch, Thorsten; Kohlstedt, Hermann

    2015-04-01

    In this work we present a phenomenological model for synaptic plasticity suitable to describe common plasticity measurements of memristive devices. We show evidence that the presented model is basically compatible with advanced biophysical plasticity models, which account for a large body of experimental data on spike-timing-depending plasticity (STDP) as an asymmetric form of Hebbian learning. The basic characteristics of our model are a saturation of the synaptic weight growth and a weight dependent learning rate. Moreover, it accounts for common resistive switching behaviors of memristive devices under voltage pulse application and allows to study essential requirements of individual memristive devices for the emulation of Hebbian plasticity in neuromorphic circuits. In this respect, memristive devices based on mixed ionic/electronic and one exclusively electronic mechanism are explored. The ionic/electronic devices consist of the layer sequence metal/isolator/metal and represent today's most popular devices. The electronic device is a MemFlash-cell which is based on a conventional floating gate transistor in a diode configuration wiring scheme exhibiting a memristive (pinched) I-V characteristic. PMID:25879966

  19. Paediatric models in motion: requirements for model-based decision support at the bedside.

    Science.gov (United States)

    Barrett, Jeffrey S

    2015-01-01

    Optimal paediatric pharmacotherapy is reliant on a detailed understanding of the individual patient including their developmental status and disease state as well as the pharmaceutical agents he/she is receiving for treatment or management of side effects. Our appreciation for size and maturation effects on the pharmacokinetic/pharmacodynamic (PK/PD) phenomenon has improved to the point that we can develop predictive models that permit us to individualize therapy, especially in the situation where we are monitoring drug effects or therapeutic concentrations. The growth of efforts to guide paediatric pharmacotherapy via model-based decision support necessitates a coordinated and systematic approach to ensuring reliable and robust output to caregivers that represents the current standard of care and adheres to governance imposed by the host institution or coalition responsible. Model-based systems which guide caregivers on dosing paediatric patients in a more comprehensive manner are in development at several institutions. Care must be taken that these systems provide robust guidance with the current best practice. These systems must evolve as new information becomes available and ultimately are best constructed from diverse data representing global input on demographics, ethnic / racial diversity, diet and other lifestyle factors. Multidisciplinary involvement at the project team level is key to the ultimate clinical valuation. Likewise, early engagement of clinical champions is also critical for the success of model-based tools. Adherence to regulatory requirements as well as best practices with respect to software development and testing are essential if these tools are to be used as part of the routine standard of care. PMID:24251868

  20. Macro-micro mechanical on joint -grout-bolt interaction in rockmass subjected to shear loading%剪切荷载下岩体结构面-浆体-锚杆相互作用机理宏细观研究

    Institute of Scientific and Technical Information of China (English)

    王刚; 袁康; 蒋宇静; 吴学震

    2015-01-01

    The mechanical behavior of bolted rock joints was researched by using bilinear constitutive model of bolt in virtue of the inner-embed FISH language of PFC based on DEM. Through a variation of the bolt’s elastic modulus and the strength of grout, their influence on macroscopic mechanical response and microscopic mechanical response of anchoring system were studied under the bolt−grout−rock interaction. The results show that there is a clear relationship between the mechanical response of bolted rock joint and the mechanical property of anchoring structures. Macroscopic aspect: the stiffer the bolt the more shear strength of bolted rock joint has. Microscopic aspect: the quantity of cracks in grout and rock increase with the increase of bolt’s stiffness so as to result in more damage to anchoring system. Cracks will appear in the joint and the intersection of bolt and joint initially. With the increase of shear displacement, the cracks in joint will be generated at the place whose compressive contact force is very concentrated while the cracks around the bolt will propagate from the intersection of bolt and joint to the two ends of bolt. Besides, the cracks are mainly concentrated on the compression side. Most of the cracks are tension cracks which are induced by compression among particles. The number of cracks in rock and grout will increase when the strength of grout is much larger or smaller. The cracks are mainly tension cracks which are result from the compression among the particles. When the strength of grout is much smaller, the cracks are mainly concentrated on the rock otherwise the cracks will be mainly distributed in grout. Therefore, the shearing strength of bolted rock joint in macroscopic aspect and the damage of anchoring system resulting from anchoring structure in microscopic aspect should be considered comprehensively while reinforcing jointed rock mass so as to realize the macroscopic-microscopic coupling support. It has a certain

  1. Prediction formulas for individual opioid analgesic requirements based on genetic polymorphism analyses.

    Directory of Open Access Journals (Sweden)

    Kaori Yoshida

    Full Text Available The analgesic efficacy of opioids is well known to vary widely among individuals, and various factors related to individual differences in opioid sensitivity have been identified. However, a prediction model to calculate appropriate opioid analgesic requirements has not yet been established. The present study sought to construct prediction formulas for individual opioid analgesic requirements based on genetic polymorphisms and clinical data from patients who underwent cosmetic orthognathic surgery and validate the utility of the prediction formulas in patients who underwent major open abdominal surgery.To construct the prediction formulas, we performed multiple linear regression analyses using data from subjects who underwent cosmetic orthognathic surgery. The dependent variable was 24-h postoperative or perioperative fentanyl use, and the independent variables were age, gender, height, weight, pain perception latencies (PPL, and genotype data of five single-nucleotide polymorphisms (SNPs. To examine the utility of the prediction formulas, we performed simple linear regression analyses using subjects who underwent major open abdominal surgery. Actual 24-h postoperative or perioperative analgesic use and the predicted values that were calculated using the multiple regression equations were incorporated as dependent and independent variables, respectively.Multiple linear regression analyses showed that the four SNPs, PPL, and weight were retained as independent predictors of 24-h postoperative fentanyl use (R² = 0.145, P = 5.66 × 10⁻¹⁰ and the two SNPs and weight were retained as independent predictors of perioperative fentanyl use (R² = 0.185, P = 1.99 × 10⁻¹⁵. Simple linear regression analyses showed that the predicted values were retained as an independent predictor of actual 24-h postoperative analgesic use (R² = 0.033, P = 0.030 and perioperative analgesic use (R² = 0.100, P = 1.09 × 10⁻⁴, respectively.We constructed

  2. Research preview: Prioritizing quality requirements based on software architecture evaluation feedback

    OpenAIRE

    Koziolek, Anne

    2012-01-01

    Context and motivation Quality requirements are a main driver for architectural decisions of software systems. Although the need for iterative handling of requirements and architecture has been identified, current architecture design processes do not provide systematic, quantitative feedback for the prioritization and cost/benefit considerations for quality requirements. Question/problem Thus, in practice stakeholders still often state and prioritize quality requirements before knowing the so...

  3. Application of Hollow Grouting Bolt to Mine Soft Rock Roadway in East Mine of Panji No.1 Mine%中空注浆锚杆在潘一矿东井软岩巷道中的应用

    Institute of Scientific and Technical Information of China (English)

    肖长春

    2014-01-01

    针对潘一矿东井-842 m东翼1号回风大巷难以支护的问题,在分析该巷道变形破坏影响因素的基础上,结合高强锚注支护技术的特点,提出了以新型树脂药卷式中空注浆锚杆为基础的高强锚注支护体系。工程试验表明,该加固方案有效地控制了巷道围岩变形,试验取得了良好的支护效果,为淮南矿区其他相似条件下巷道围岩控制提供了参考依据。%For the East Mine of Panyi No.1 Mine -842m East Wing No.1 air return roadway is difficult to support ,based on the factors of deformation and failure of roadway ,this paper combined with the high strength bolt grouting support technology characteristic and put forward the high-strength bol-ting support system based the new resin cartridge type hollow grouting anchor .Engineering test ,the reinforcement scheme can effectively control the deformation of roadway surrounding rock ,the test a-chieved good supporting effect ,and for the Huainan mining area of roadway surrounding rock under the condition of other similar control provides a reference.

  4. Materials for Advanced Ultrasupercritical Steam Turbines Task 3: Materials for Non-Welded Rotors, Buckets, and BoltingMaterials for Advanced Ultrasupercritical Steam Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Deepak

    2015-09-15

    The primary objective of the task was to characterize the materials suitable for mechanically coupled rotor, buckets and bolting operating with an inlet temperature of 760°C (1400°F). A previous study DOE-FC26-05NT42442, identified alloys such as Haynes®282®, Nimonic 105, Inconel 740, Waspaloy, Nimonic 263, and Inconel 617 as potential alloys that met the requirements for the necessary operating conditions. Of all the identified materials, Waspaloy has been widely utilized in the aviation industry in the form of disk and other smaller forgings, and sufficient material properties and vendor experience exist, for the design and manufacture of large components. The European program characterizing materials for A-USC conditions are evaluating Nimonic 263 and Inconel 617 for large components. Inconel 740 has been studied extensively as a part of the boiler consortium and is code approved. Therefore, the consortium focused efforts in the development of material properties for Haynes®282® and Nimonic 105 to avoid replicative efforts and provide material choices/trade off during the detailed design of large components. Commercially available Nimonic 105 and Haynes®282® were evaluated for microstructural stability by long term thermal exposure studies. Material properties requisite for design such as tensile, creep / rupture, low cycle fatigue, high cycle fatigue, fatigue crack growth rate, hold-time fatigue, fracture toughness, and stress relaxation are documented in this report. A key requisite for the success of the program was a need demonstrate the successful scale up of the down-selected alloys, to large components. All property evaluations in the past were performed on commercially available bar/billet forms. Components in power plant equipment such as rotors and castings are several orders in magnitude larger and there is a real need to resolve the scalability issue. Nimonic 105 contains high volume fraction y’ [>50%], and hence the alloy is best suited

  5. 基于工作流的需求管理解决方案%Requirement Management Based on Workflow

    Institute of Scientific and Technical Information of China (English)

    胡胜玉; 刘烨辉

    2011-01-01

    Based on the analysis of many aspects of Requirement Management,it achieved a Requirement Management solution integrating with Workflow well,which put forward integrating Workflow technology in Requirement State Tracing and Requirement Change Control stag%在分析了需求管理各个方面的基础上,在需求状态跟踪和需求变更控制阶段提出结合工作流技术,较好地实现了一种与工作流结合的需求管理解决方案。

  6. Ethanolamine requirement of mammary epithelial cells is due to reduced activity of base exchange enzyme

    International Nuclear Information System (INIS)

    Epithelial cells and some of their transformed derivatives require ethanolamine (Etn) to proliferate normally in defined culture medium. The amount of cellular phosphatidylethanolamine (PtdEtn) is considerably reduced when these cells are cultured without Etn. Using Etn-responsive and -nonresponsive rat mammary carcinoma cell lines, the biochemical mechanism of Etn-responsiveness of investigated. The incorporation of [3H]serine into phosphatidylserine (PtdSer) and PtdEtn in Etn-responsive cells was 60 and 37%, respectively, of those in Etn-nonresponsive cells. There was no significant difference between the two cell types in the activities of enzymes involved in PtdEtn synthesis via CDP-Etn. The activity of PtdSer decarboxylase was also very similar in these two cell types. When these cells were cultured in the presence of [32P]PtdEtn, the rate of accumulation of [32P]-labeled PtdSer from the radioactive PtdEtn was considerably reduced in Etn-responsive cells as compared to Etn-nonresponsive cells. Whereas there was no significant difference in the accumulation of the labeled PtdSer from [32P]phosphatidylcholine. These results demonstrate that the Etn-responsiveness is due to a limited ability to synthesize PtdSer resulting from a limited base exchange activity utilizing PtdEtn

  7. Requirements analysis of airborne gravity gradiometry on moving-based platform

    Science.gov (United States)

    Tu, L.; Li, Z.; Wu, W.

    2014-12-01

    Airborne gravity and gravity gradient measurement are the most effective ways for the earth gravitational field measurement. Gravity gradient is a derivative of gravity acceleration, due to the high order feature of gravity gradient, it is more sensitive to short wave component, and can reflect the details of the source so that the gravity gradient measurement has wide applications in geophysical science, resource exploration, and inertial navigation. Airborne gravity gradient measurement uses the plane or ship as the platform, and it is efficient and high precision. In this paper, We compared the gravity and gravity gradient measurement, and analyzed the advantages of the gravity gradient measurement compared with gravity measurement. The airborne gravity gradient measurement system and the inertial stabilization platform were discussed. By setting a goal sensitivity of the gravity gradient measurement being 1 E/√Hz, the key factors of the stabilized platform, namely the pointing accuracy, pointing stability, and gyroscope random drift, are 0.5°, 0.01°/hr/√Hz, and 0.01°/hr respectively. Compared with the airborne gravity measurement whose goal sensitivity is 1mGal/√Hz, the requirements of moving-based gravity gradient measurement on the inertial stabilization platform is significantly lower and hence easy to realize, and the major reason is the differential measurement mode being used.

  8. Requirements for Control Room Computer-Based Procedures for use in Hybrid Control Rooms

    Energy Technology Data Exchange (ETDEWEB)

    Le Blanc, Katya Lee [Idaho National Lab. (INL), Idaho Falls, ID (United States); Oxstrand, Johanna Helene [Idaho National Lab. (INL), Idaho Falls, ID (United States); Joe, Jeffrey Clark [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-05-01

    Many plants in the U.S. are currently undergoing control room modernization. The main drivers for modernization are the aging and obsolescence of existing equipment, which typically results in a like-for-like replacement of analogue equipment with digital systems. However, the modernization efforts present an opportunity to employ advanced technology that would not only extend the life, but enhance the efficiency and cost competitiveness of nuclear power. Computer-based procedures (CBPs) are one example of near-term advanced technology that may provide enhanced efficiencies above and beyond like for like replacements of analog systems. Researchers in the LWRS program are investigating the benefits of advanced technologies such as CBPs, with the goal of assisting utilities in decision making during modernization projects. This report will describe the existing research on CBPs, discuss the unique issues related to using CBPs in hybrid control rooms (i.e., partially modernized analog control rooms), and define the requirements of CBPs for hybrid control rooms.

  9. Torque ultra difference fault analysis of flywheel bolt tightening machine%飞轮螺栓拧紧机力矩超差问题分析

    Institute of Scientific and Technical Information of China (English)

    李绍红

    2013-01-01

    对轿车发动机主装配线飞轮螺栓拧紧机力矩超差原因进行分析并排除故障.%In this paper, the main assembly line for car engine flywheel bolt tightening machine torque error cause is analyzed, and the troubleshooting process is described.

  10. Automata learning algorithms and processes for providing more complete systems requirements specification by scenario generation, CSP-based syntax-oriented model construction, and R2D2C system requirements transformation

    Science.gov (United States)

    Hinchey, Michael G. (Inventor); Margaria, Tiziana (Inventor); Rash, James L. (Inventor); Rouff, Christopher A. (Inventor); Steffen, Bernard (Inventor)

    2010-01-01

    Systems, methods and apparatus are provided through which in some embodiments, automata learning algorithms and techniques are implemented to generate a more complete set of scenarios for requirements based programming. More specifically, a CSP-based, syntax-oriented model construction, which requires the support of a theorem prover, is complemented by model extrapolation, via automata learning. This may support the systematic completion of the requirements, the nature of the requirement being partial, which provides focus on the most prominent scenarios. This may generalize requirement skeletons by extrapolation and may indicate by way of automatically generated traces where the requirement specification is too loose and additional information is required.

  11. The use of hydraulic bolts for coupling in order to shorten the maintenance critical path in turbo generator sites; Uso de tornillos hidraulicos para acoplamiento a fin de acortar la ruta critica del mantenimiento en sitios de turbogeneradores

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Arelle, Carlos [Turbomaquinas S. A. de C.V., La Piedad, Michoacan (Mexico)

    2007-11-15

    The use of hydraulic bolts has permitted to diminish the time in the critical path of the maintenance, attaining to reduce the total costs and avoiding that some bolts are stuck, benefits the on time planning of the maintenance. The bolts of radial adjustment provide significant benefits to the General Turbine operator. The hydraulic bolts avoid the normal problems of the conventional coupling bolts and rapidly help to re-establish the couple concentricity. The bolts are individually designed to meet a specific geometry and are a direct replacement of the conventional bolts. [Spanish] El uso de tornillos hidraulicos ha permitido disminuir el tiempo de la ruta critica del mantenimiento, logrando reducir los costos totales y al evitar que algun tornillo se atore, beneficia la planeacion de mantenimientos a tiempo. Los tornillos de ajuste radial proveen beneficios significativos al operador de la Turbina General. Los tornillos hidraulicos eliminan los problemas normales de los tornillos de acoplamiento convencionales y rapidamente ayudan a restablecer la concentridad del cople. Los tornillos son disenados individualmente para completar una geometria especifica y son un reemplazo directo de los tornillos convencionales.

  12. A PRIORITY-BASED NEGOTIATIONS APPROACH FOR HANDLING INCONSISTENCIES IN MULTI-PERSPECTIVE SOFTWARE REQUIREMENTS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Inconsistency of multi-perspective requirements specifications is a pervasive issue during the requirements process.However,managing inconsistency is not just a pure technical problem.It is always associated with a process of interactions and competitions among corresponding stakeholders.The main contribution of this paper is to present a negotiations approach to handling inconsistencies in multi-perspective software requirements.In particular,the priority of requirements relative to each perspective plays an important role in proceeding negotiation over resolving inconsistencies among different stakeholders.An algorithm of generating negotiation proposals and an approach to evaluating proposals are also presented in this paper,respectively.

  13. Forecasting Model of Coal Requirement Quantity Based on Grey System Theory

    Institute of Scientific and Technical Information of China (English)

    孙继湖

    2001-01-01

    The generally used methods of forecasting coal requirement quantity include the analogy method, the outside-push method and the cause-effect analysis method. However, the precision of forecasting results using these methods is lower. This paper uses the grey system theory, and sets up grey forecasting model GM (1, 3) to coal requirement quantity. The forecasting result for the Chinese coal requirement quantity coincides with the actual values, and this shows that the model is reliable. Finally, this model are used to forecast Chinese coal requirement quantity in the future ten years.

  14. An Approach to Automatic Generation of Test Cases Based on Use Cases in the Requirements Phase

    Directory of Open Access Journals (Sweden)

    U.Senthil Kumaran

    2011-01-01

    Full Text Available The main aim of this paper is to generate test cases from the use cases. In the real-time scenario we have to face several issues like inaccuracy, ambiguity, and incompleteness in requirements this is because the requirements are not properly updated after various change requests. This will reduce the quality of test cases. To overcome these problems we develop a solution which generates test cases at the early stages of system development life cycle which captures maximum number of requirements. As requirements are best captured by use cases our focus lies on generating test cases from use case diagrams.

  15. COMPOSITE MATERIAL BOLT THREADED NUT CONTACT FINITE ELEMENT ANALYSIS%复合材料锚杆螺纹螺帽接触有限元分析

    Institute of Scientific and Technical Information of China (English)

    温敏; 崔小朝; 王红霞

    2008-01-01

    利用ANSYS大型分析软件,建立属于表面非线性和材料非线性相耦合问题的复合材料锚杆螺纹螺帽联接的弹塑性轴对称接触有限元模型.对复合材料锚杆螺纹螺帽在间隙配合时轴向载荷作用下的应力应变场进行了数值计算.计算结果表明,复合材料锚杆螺纹螺帽联接能够满足煤矿安全生产的强度和刚度要求,为复合材料螺纹螺帽联接的设计提供了理论依据,对复合材料锚杆螺纹螺帽联接在工程实际中的推广使用有着重要的意义.%By means of large-scale analysis software ANSYS, a finite element model of elastic plastic axial symmetry contact problem is established which remained with the nonlinear surface and the nonlinear materials for the connecting of composite material bolt threaded nut. Stress-strain field has been calculated under the axial load with gap coordination of the composite material bolt threaded nut. The results indicate that, the joint of the composite material bolt threaded nut can satisfy the intensity and the rigidity request for the coal mine safety production. The researches in the paper have provided theoretical basis for the design of connecting the composite material bolt thread nut, and have important significance for widely using of the composite material bolt thread nut in project.

  16. Failure Analysis of Ruptured Bolts in Coal Gas Heater%煤气加热器断裂螺栓的失效分析

    Institute of Scientific and Technical Information of China (English)

    朱岗; 邱艳丽; 杨振国

    2008-01-01

    对350 MW燃气轮机发电装置煤气加热器盲板上的螺栓断裂的失效机理及其起因进行了系统性的研究. 采用一系列的微宏观表征方法,分析其化学组成、金相结构、宏观外形、微观形态和微区的化学结构. 试验结果表明:螺栓的失效主要是由其材质不良、表面加工不当、紧固力不合理以及腐蚀环境等共同作用造起的. 进一步讨论了螺栓的电偶腐蚀、缝隙腐蚀和应力腐蚀开裂的相关机理,并提出相应的预防措施.%The failure mechanisms and causes of the ruptured bolts of blind plate on a coal gas heater of 350 MW gas turbine generating unit were systematically studied. A series of macroscopic and microscopic analysis methods were used to characterize chemical composition, metallographic structure, macroscopic appearance, microscopic morphology and microarea chemical composition of the bolts. The experimental results showed that the failure of the bolts were mainly caused by galvanic corrosion, crevice corrosion and followed stress corrosion cracking, which were resulted from inferior material, unqualified processing quality, and unsuitable fastening force and corrosive environment. The relevant mechanisms on crevice corrosion and stress corrosion cracking of the bolts were carefully discussed and countermeasures for preventing the bolts were also proposed.

  17. 40 CFR 745.325 - Lead-based paint activities: State and Tribal program requirements.

    Science.gov (United States)

    2010-07-01

    ... Tribal program requirements. 745.325 Section 745.325 Protection of Environment ENVIRONMENTAL PROTECTION... appropriate infrastructure or government capacity to effectively carry out a State or Tribal program. (b...) Environmental sampling for lead in paint, dust, and soil; (C) Environmental sampling requirements for lead...

  18. Generating Logical Specifications from Requirements Models for Deduction-based Formal Verification

    OpenAIRE

    Klimek, Radoslaw

    2014-01-01

    The work concerns automatic generation of logical specifications from requirements models. Logical specifications obtained in such a way can be subjected to formal verification using deductive reasoning. Formal verification concerns correctness of a model behaviour. Reliability of the requirements engineering is essential for all phases of software development processes. Deductive reasoning is an important alternative among other formal methods. However, logical specifications, considered as ...

  19. Innovative Product Design Based on Comprehensive Customer Requirements of Different Cognitive Levels

    Directory of Open Access Journals (Sweden)

    Xiaolong Li

    2014-01-01

    Full Text Available To improve customer satisfaction in innovative product design, a topology structure of customer requirements is established and an innovative product approach is proposed. The topology structure provides designers with reasonable guidance to capture the customer requirements comprehensively. With the aid of analytic hierarchy process (AHP, the importance of the customer requirements is evaluated. Quality function deployment (QFD is used to translate customer requirements into product and process design demands and pick out the technical requirements which need urgent improvement. In this way, the product is developed in a more targeted way to satisfy the customers. the theory of innovative problems solving (TRIZ is used to help designers to produce innovative solutions. Finally, a case study of automobile steering system is used to illustrate the application of the proposed approach.

  20. Innovative product design based on comprehensive customer requirements of different cognitive levels.

    Science.gov (United States)

    Li, Xiaolong; Zhao, Wu; Zheng, Yake; Wang, Rui; Wang, Chen

    2014-01-01

    To improve customer satisfaction in innovative product design, a topology structure of customer requirements is established and an innovative product approach is proposed. The topology structure provides designers with reasonable guidance to capture the customer requirements comprehensively. With the aid of analytic hierarchy process (AHP), the importance of the customer requirements is evaluated. Quality function deployment (QFD) is used to translate customer requirements into product and process design demands and pick out the technical requirements which need urgent improvement. In this way, the product is developed in a more targeted way to satisfy the customers. the theory of innovative problems solving (TRIZ) is used to help designers to produce innovative solutions. Finally, a case study of automobile steering system is used to illustrate the application of the proposed approach.

  1. Innovative product design based on comprehensive customer requirements of different cognitive levels.

    Science.gov (United States)

    Li, Xiaolong; Zhao, Wu; Zheng, Yake; Wang, Rui; Wang, Chen

    2014-01-01

    To improve customer satisfaction in innovative product design, a topology structure of customer requirements is established and an innovative product approach is proposed. The topology structure provides designers with reasonable guidance to capture the customer requirements comprehensively. With the aid of analytic hierarchy process (AHP), the importance of the customer requirements is evaluated. Quality function deployment (QFD) is used to translate customer requirements into product and process design demands and pick out the technical requirements which need urgent improvement. In this way, the product is developed in a more targeted way to satisfy the customers. the theory of innovative problems solving (TRIZ) is used to help designers to produce innovative solutions. Finally, a case study of automobile steering system is used to illustrate the application of the proposed approach. PMID:25013862

  2. Depillaring of total thickness of a thick coal seam in single lift using cable bolts:A case study

    Institute of Scientific and Technical Information of China (English)

    Kumar Rakesh; Mishra Arvind Kumar; Singh Arun Kumar; Singh Amit Kumar; Ram Sahendra; Singh Rajendra

    2016-01-01

    Explaining fundamentals of application of cable bolting for a thick seam depillaring, this paper summa-rizes the results of field studies conducted during adoption of this approach in more than fifteen panels of Madhusudanpur 7 pit and incline mine. Nearly 7.0 m thick Kajora top coal seam of this mine is developed on pillars along the floor horizon to an average height of 3.0 m, leaving a coal band of around 4.0 m along the roof. Analysis of procured core samples showed that roof strata are easily caveable with a caveability index value of around 2000 only. Easily caveable overlying strata and shallow depth of cover alleviated most of the expected strata mechanics problems of the thick seam mining. However, extraction of total thickness at shallow cover caused differential-subsidence and cracks on the surface. These manifestations were immediately tackled to avoid creation of a breathing path for spontaneous heating in the extracted area.

  3. A New Approach to Requirement Elicitation Based on Stakeholder Recommendation andCollaborative Filtering

    Directory of Open Access Journals (Sweden)

    Nilofar Mulla

    2012-06-01

    Full Text Available The customers' needs in a software project are identified in the process of Software requirements elicitation. For building a software system this process is considered as one of the most important parts. In this part it is decided precisely what will be built. A close interaction between developers and end-users of the system is needed by requirements’ gathering. Meetings can be costly, inconvenient and infrequent if developers and end-users are in different organizations or different cities. The quality of the elicited requirements can greatly be impacted if there is a problem of communication. Requirement elicitation is a process difficult to scale to large software projects with many stakeholders which involves identifying and prioritizing requirements. A stakeholder is an individual or a group who can influence or be influenced by the success or failure of a project. Existing methods to identify and prioritize requirements do not scale well to large projects. Large projects tend to be beset by three problems: information overload, inadequate stakeholder input, and biased prioritization of requirements. Existing methods to identify and prioritize requirements do not scale well to large projects. Existing requirements prioritization methods requiresubstantial efforts from the requirements engineers when there are many requirements. To address the problems Stakeholder recommender model will contain steps:-Identify the large project, Analysis of requirements, Identify and prioritize stakeholders, Predict requirements, Prioritize requirements. Formaking predictions, our approach will use one of the most well known algorithms that is k-Nearest Neighbor (kNN algorithm. KNN is used to identify like-minded users with similar rating histories in order to predict ratings for unobserved users-item pairs. A unique subset of the community for each user is found out by KNN by identifying those with similar interests. To do so, every pair of user profile

  4. Experiences with a Requirements-Based Programming Approach to the Development of a NASA Autonomous Ground Control System

    Science.gov (United States)

    Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.; Gracanin, Denis; Erickson, John

    2005-01-01

    Requirements-to-Design-to-Code (R2D2C) is an approach to the engineering of computer-based systems that embodies the idea of requirements-based programming in system development. It goes further; however, in that the approach offers not only an underlying formalism, but full formal development from requirements capture through to the automatic generation of provably-correct code. As such, the approach has direct application to the development of systems requiring autonomic properties. We describe a prototype tool to support the method, and illustrate its applicability to the development of LOGOS, a NASA autonomous ground control system, which exhibits autonomic behavior. Finally, we briefly discuss other areas where the approach and prototype tool are being considered for application.

  5. Tests and analysis of mechanical behaviours of rock bolt components for China’s coal mine roadways

    Institute of Scientific and Technical Information of China (English)

    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%e58.3% and 17.2%e28.7% greater than those of the conventional rebar, respectively. The increase in yield strength was higher than that in tensile strength, suggesting an increase in yield to tensile strength ratio and a decrease in elongation. It is well-known that the thread processing may not be of high precision and accuracy as expected, which is characterised as rough thread surface, non-identical tooth height, toe stripping, and cracks in the surface. Hardening during thread processing tends to increase the thread yield and tensile strengths. In this paper, the typical deformation process of arch-shaped plate is classified into five stages. The tested plates exhibited distinct deformation characteristics and bearing capacities due to variations in shape, size, material and presence of washer. It was observed that uneven bottom surface, low bearing arch and large radius of the transitional arc connecting bearing arch and bottom surface were the major reasons ac-counting for low load-bearing capacity of plates. The performance of domed washer has a close relation with the shape, size, strength, and deformation compatibility with plate. Stress concentration was observed on the periphery of the contact surface between domed washer and plate, which is significantly influenced by the strength of domed washer and is considered to be 20%e30%higher than that of plate. Finally, a case study in the Datong coal mining district was presented, and the support pattern and effect of the developed rock bolt

  6. Multiple-Viewpoints Based Requirements Engineering Approaches%基于多视点的需求工程方法

    Institute of Scientific and Technical Information of China (English)

    何炎祥; 黄浩; 石莉; 张戈; 李超

    2000-01-01

    Requirements specification is one of the most important problems in software development. The main objective of the requirements engineering is to provide a model of what is needed in a clear, precise, unambiguous and consistent statement of the system to be specified. Viewpoints are seen as a means for separating concerns in software development in accordance with a variety of criteria, which has a significant role in achieving a successful system. The paper is a survey of the current multiple viewpoints based requirements approaches; a simple example of a distributed multimedia conferencing system is used to demonstrate them.

  7. Quality Requirements Elicitation based on Inquiry of Quality-Impact Relationships

    OpenAIRE

    Fotrousi, Farnaz; Fricker, Samuel (Ed.); Fiedler, Markus

    2014-01-01

    Quality requirements, an important class of non functional requirements, are inherently difficult to elicit. Particularly challenging is the definition of good-enough quality. The problem cannot be avoided though, because hitting the right quality level is critical. Too little quality leads to churn for the software product. Excessive quality generates unnecessary cost and drains the resources of the operating platform. To address this problem, we propose to elicit the specific relationships ...

  8. Direction for the Estimation of Required Resources for Nuclear Power Plant Decommissioning based on BIM via Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Insu [Korea Institute of Construction Technology, Goyang (Korea, Republic of); Kim, Woojung [KHNP-Central Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Ways to estimate decommissioning of required resources in the past have imposed great uncertainty since they analyze required resources at the construction stage, analyzing and consulting decommissioning required resources of overseas nuclear power plants. As demands on efficient management and use of complicated construction information increased these days, demands on the introduction of Building Information Modeling (herein after referred to as BIM) technology has increased. In the area of quotation, considerable effects are expected as to the accuracy and reliability predicting construction costs through the characteristics that can automatically estimate quantities by using attribute information of BIM model. BIM-based estimation and quotation of required resources is more accurate than the existing 2D-based quotations and have many advantages such as reviews over constructability and interference. It can be desirable to estimate decommissioning required resources in nuclear power plants using BIM as well as using tools that are compatible with usual international/industrial standards. As we looked into the cases where required resources were estimated, using BIM in Korea and abroad, they dealt with estimation of required resources, estimation of construction cost and process management at large. In each area, methodologies, classification systems, BIM, and realization tests have been used variably. Nonetheless, several problems have been reported, and among them, it is noticeable that although BIM standard classification system exists, no case was found that has used standard classification system. This means that no interlink among OBS (Object Breakdown Structure), WBS (Work Breakdown Structure) and CBS (Cost Breakdown Structure) was possible. Thus, for nuclear power plant decommissioning, decommissioning method and process, etc. shall be defined clearly in the stage of decommissioning strategy establishment, so that classification systems must be set up

  9. Direction for the Estimation of Required Resources for Nuclear Power Plant Decommissioning based on BIM via Case Study

    International Nuclear Information System (INIS)

    Ways to estimate decommissioning of required resources in the past have imposed great uncertainty since they analyze required resources at the construction stage, analyzing and consulting decommissioning required resources of overseas nuclear power plants. As demands on efficient management and use of complicated construction information increased these days, demands on the introduction of Building Information Modeling (herein after referred to as BIM) technology has increased. In the area of quotation, considerable effects are expected as to the accuracy and reliability predicting construction costs through the characteristics that can automatically estimate quantities by using attribute information of BIM model. BIM-based estimation and quotation of required resources is more accurate than the existing 2D-based quotations and have many advantages such as reviews over constructability and interference. It can be desirable to estimate decommissioning required resources in nuclear power plants using BIM as well as using tools that are compatible with usual international/industrial standards. As we looked into the cases where required resources were estimated, using BIM in Korea and abroad, they dealt with estimation of required resources, estimation of construction cost and process management at large. In each area, methodologies, classification systems, BIM, and realization tests have been used variably. Nonetheless, several problems have been reported, and among them, it is noticeable that although BIM standard classification system exists, no case was found that has used standard classification system. This means that no interlink among OBS (Object Breakdown Structure), WBS (Work Breakdown Structure) and CBS (Cost Breakdown Structure) was possible. Thus, for nuclear power plant decommissioning, decommissioning method and process, etc. shall be defined clearly in the stage of decommissioning strategy establishment, so that classification systems must be set up

  10. Job requirements compared to medical school education: differences between graduates from problem-based learning and conventional curricula

    Directory of Open Access Journals (Sweden)

    Federkeil Gero

    2010-01-01

    Full Text Available Abstract Background Problem-based Learning (PBL has been suggested as a key educational method of knowledge acquisition to improve medical education. We sought to evaluate the differences in medical school education between graduates from PBL-based and conventional curricula and to what extent these curricula fit job requirements. Methods Graduates from all German medical schools who graduated between 1996 and 2002 were eligible for this study. Graduates self-assessed nine competencies as required at their day-to-day work and as taught in medical school on a 6-point Likert scale. Results were compared between graduates from a PBL-based curriculum (University Witten/Herdecke and conventional curricula. Results Three schools were excluded because of low response rates. Baseline demographics between graduates of the PBL-based curriculum (n = 101, 49% female and the conventional curricula (n = 4720, 49% female were similar. No major differences were observed regarding job requirements with priorities for "Independent learning/working" and "Practical medical skills". All competencies were rated to be better taught in PBL-based curriculum compared to the conventional curricula (all p Conclusion Among medical graduates in Germany, PBL demonstrated benefits with regard to competencies which were highly required in the job of physicians. Research and business competence deserve closer attention in future curricular development.

  11. Estimation of the Required Modeling Depth for the Simulation of Cable Switching in a Cable-based Network

    DEFF Research Database (Denmark)

    Silva, Filipe Faria Da; Bak, Claus Leth; Balle Holst, Per

    2012-01-01

    . If the area is too large, the simulation requires a long period of time and numerical problems are more likely to exist. This paper proposes a method that can be used to estimate the depth of the modeling area using the grid layout, which can be obtained directly from a PSS/E file, or equivalent....... The simulation of electromagnetic transients in cable-based networks requires larger computational effort than in an equivalent overhead-line (OHL)-based network. Therefore, the method is demonstrated for the former, with the cases of OHL-based networks and hybrid cable-OHL networks addressed in a future paper....... One of the main reasons behind the long simulation times of a cable-based network is the simulation of all the cross-bonded sections. The introduced method can also be used to minimize the modeling of the cross-bonded sections....

  12. REINFORCING MECHANISM AND SIMULATING METHOD FOR REINFORCING EFFECTS OF SYSTEMICALLY GROUTED BOLTS IN DEEP-BURIED HARD ROCK TUNNELS%深埋硬岩隧洞系统砂浆锚杆的加固机制与加固效果模拟方法

    Institute of Scientific and Technical Information of China (English)

    吴文平; 冯夏庭; 张传庆; 邱士利; 李占海

    2012-01-01

    Systematically grouted bolts, as the main support structure of deep-buried hard rock tunnels, compose the bolt-rock composite structure with surrounding rocks. which reinforces the mechanical property of surrounding rocks. Based on the Mohr-Coulomb(M-C) criterion, the stress condition and the strength of the composite structure meeting the M-C criterion were derived under high-stress conditions. Combining with the rock mass deterioration model(RDM) of brittle rock, an approach to determine the mechanical parameters of the composite structure was presented. The difference of mechanical parameters between two different composite structures of bolt-elastic surrounding rock and bolt-yielding surrounding rock was taken into account. In this approach, the mechanical parameters of the bolt-yielding surrounding rock composite structure were associated with present equivalent plastic strain of surrounding rocks. A numerical method, which could model the reinforcing effect of normally grouted bolts laid out systematically during excavating and supporting stages, was proposed. It is identified that this method has an advantage over other methods in modeling the effect of supporting time on surrounding rock stability. Finally, the method was applied to evaluate the stability of surrounding rocks, and related references were provided for design and construction of the diversion tunnel #2 of Jinping Ⅱ hydropower station.%系统布置的砂浆锚杆是深埋硬岩隧洞主要支护结构,锚杆与围岩组成锚杆-围岩复合结构体,使围岩的力学特性得到改善.基于岩体的莫尔-库仑(M-C)屈服准则,推导锚杆-围岩复合结构体满足M-C准则的应力条件.结合岩体劣化本构模型,提出确定锚杆-围岩复合结构体力学参数的方法.锚杆与弹性围岩和屈服围岩组成的锚杆-围岩复合结构体的力学参数确定方法不同,锚杆与屈服围岩组成的锚杆-围岩复合结构体的力学参数与围岩当前状态的等

  13. The analysis of normative requirements to materials of PWR components, basing on LBB concepts

    Energy Technology Data Exchange (ETDEWEB)

    Anikovsky, V.V.; Karzov, G.P.; Timofeev, B.T. [CRISM Prometey, St. Petersburg (Russian Federation)

    1997-04-01

    The paper discusses the advisability of the correction of Norms to solve in terms of material science the Problem: how the normative requirements to materials must be changed in terms of the concept {open_quotes}leak before break{close_quotes} (LBB).

  14. 77 FR 27561 - Requirements for Fingerprint-Based Criminal History Records Checks for Individuals Seeking...

    Science.gov (United States)

    2012-05-11

    ... Access to Research and Test Reactors'' (72 FR 25337; May 4, 2007), and Order EA-07-098, ``Issuance of... the General Atomics' Research and Test Reactors'' (72 FR 44590; August 8, 2007)). Specifically, the...., fuel), within the research and test reactor facilities. Licensees were required to submit...

  15. A Curriculum Model: Engineering Design Graphics Course Updates Based on Industrial and Academic Institution Requirements

    Science.gov (United States)

    Meznarich, R. A.; Shava, R. C.; Lightner, S. L.

    2009-01-01

    Engineering design graphics courses taught in colleges or universities should provide and equip students preparing for employment with the basic occupational graphics skill competences required by engineering and technology disciplines. Academic institutions should introduce and include topics that cover the newer and more efficient graphics…

  16. Developing a Standard Based Advanced Lab Course that Fulfills COM3 Requirements

    Science.gov (United States)

    Michalak, Rudi

    2015-03-01

    An advanced physics lab has been developed into a course that fulfills the requirements for a university studies program `COM3' course using Standard Teaching (ST) methods. The COM3 course is a capstone course under the new USP2015 study requirements for all majors. It replaces the WC writing requirement, typically filled in the English Dept., and adds the teaching of oral and digital communication skills. ST is a method that replaces typical assessments (homework / exam grades) with new assessments that measure certain specified learning outcomes. In combination with oral assessments and an oral final exam, the ST proves an efficient tool to implement the USP Learning Outcomes into a physics course. COM3 requires an unprecedented seven learning outcomes in a single course. Variety of learning outcomes: interdisciplinary goals, levels of writing (with drafting steps), organizational structure, standard language metrics, research and presentation deliverance skills, appropriate addressing of a variety of audiences, etc. With other assessment approaches than ST this variety would be difficult to meet in a physics course. An extended ST rubric has been developed for this course and will be presented and discussed in some detail.

  17. The analysis of normative requirements to materials of PWR components, basing on LBB concepts

    International Nuclear Information System (INIS)

    The paper discusses the advisability of the correction of Norms to solve in terms of material science the Problem: how the normative requirements to materials must be changed in terms of the concept open-quotes leak before breakclose quotes (LBB)

  18. A Mobile Location-Based Situated Learning Framework for Supporting Critical Thinking--A Requirements Analysis Study

    Science.gov (United States)

    Alnuaim, Abeer; Caleb-Solly, Praminda; Perry, Christine

    2012-01-01

    This paper presents the requirements work carried out as part of developing an intervention to improve students' critical thinking skills using location-based mobile learning. The research emerged from seeking to identify ways of getting Interaction Design students into real world environments, similar to those in which they will eventually be…

  19. 78 FR 4365 - Capital, Margin, and Segregation Requirements for Security-Based Swap Dealers and Major Security...

    Science.gov (United States)

    2013-01-22

    ... Friday, February 22, 2013. \\1\\ See Exchange Act Release No. 68071 (Oct. 18, 2012), 77 FR 70213 (Nov. 23... COMMISSION 17 CFR Part 240 RIN 3235-AL12 Capital, Margin, and Segregation Requirements for Security-Based... Federal Register a proposed rule for public comment to establish capital, margin, and...

  20. The Prediction of Job Ability Requirements Using Attribute Data Based Upon the Position Analysis Questionnaire (PAQ). Technical Report No. 1.

    Science.gov (United States)

    Shaw, James B.; McCormick, Ernest J.

    The study was directed towards the further exploration of the use of attribute ratings as the basis for establishing the job component validity of tests, in particular by using different methods of combining "attribute-based" data with "job analysis" data to form estimates of the aptitude requirements of jobs. The primary focus of the study…