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Numerical Simulation Analysis of Welded Joints in Arch Ribs of Large Span Steel Pipe Arch Bridges
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作者 Deer He Nianchun Deng Xiuning Peng 《Journal of Harbin Institute of Technology(New Series)》 CAS 2024年第3期19-30,共12页
In order to study the residual stress distribution law of welded joints of arch ribs of large-span steel pipe concrete arch bridges,numerical simulation of temperature,stress and strain fields based on ABAQUS for weld... In order to study the residual stress distribution law of welded joints of arch ribs of large-span steel pipe concrete arch bridges,numerical simulation of temperature,stress and strain fields based on ABAQUS for welded joints of arch-ribbed steel tubes using 7-,8-and 9-layer welds is carried out and its accuracy is demonstrated.The steel pipe welding temperature changes,residual stress distribution,different processes residual stress changes in the law,the prediction of post-weld residual stress distribution and deformation are studied in this paper.The results show that the temperature field values and test results are more consistent with the accuracy of numerical simulation of welding,the welding process is mainly in the form of heat transfer;Residual high stresses are predominantly distributed in the Fusion zone(FZ)and Heat-affected zone(HAZ),with residual stress levels tending to decrease from the center of the weld along the axial path,the maximum stress appears in the FZ and HAZ junction;The number of welding layers has an effect on the residual stress distribution,the number of welding layers increases,the residual stress tends to decrease,while the FZ and HAZ high stress area range shrinks;Increasing the number of plies will increase the amount of residual distortion. 展开更多
关键词 steel pipe and concrete arch bridge arch rib multi-pass welding residual stress numerical simulation
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AN IMPROVED FOSM METHOD FOR CALCULATING FAILURE PROBABILITY OF WELDED PIPES WITH FLAWS 被引量:1
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作者 刘敏 霍立兴 张玉凤 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1999年第2期188-192,共5页
The R F first order second moment method will produce more error for calculating the reliability of welded engineering pipe structures when the failure function is seriously nonlinear and the random variables don... The R F first order second moment method will produce more error for calculating the reliability of welded engineering pipe structures when the failure function is seriously nonlinear and the random variables don′t serve as normal distribution. In order to increase the computing accuracy of reliability, an improved FOSM method is used for calculating the failure probability of welded pipes with flaws in this paper. Because of solving the problems of the linear expansion of failure function at the failure point and constructing equivalent normal variables, the new algorithm can greatly improve the calculating accuracy of probability of the welded pipes with cracks. The examples show that this method is simple, efficient and accurate for reliability safety assessment of the welded pipes with cracks. It can save more time than the Monte Carlo method does, so that the improved FOSM method is recommended for engineering reliability safety assessment of the welded pipes with flaws. 展开更多
关键词 welded structure failure probability FLAWS pipeS first order second moment
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Pose Planning for the End-effector of Robot in the Welding of Intersecting Pipes 被引量:9
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作者 LIU Yu ZHAO Jing LU Zhenyang CHEN Shujun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第2期264-270,共7页
All-position robots are widely applied in the welding of complicated parts.Welding of intersecting pipes is one of the most typical tasks.The welding seam is a complicated saddle-like space curve,which puts a great ch... All-position robots are widely applied in the welding of complicated parts.Welding of intersecting pipes is one of the most typical tasks.The welding seam is a complicated saddle-like space curve,which puts a great challenge to the pose planning of end-effector.The special robots designed specifically for this kind of tasks are rare in China and lack sufficient theoretical research.In this paper,a systematic research on the pose planning for the end-effectors of robot in the welding of intersecting pipes is conducted. First,the intersecting curve of pipes is mathematically analyzed.The mathematical model of the most general intersecting curve of pipes is derived,and several special forms of this model in degraded situations are also discussed.A new pose planning approach of bisecting angle in main normal plane(BAMNP) for the welding-gun is proposed by using differential geometry and the comparison with the traditional bisecting angle in axial rotation plane(BAARP) method is also analytically conducted.The optimal pose of the welding-gun is to make the orientation posed at the center of the small space formed by the two cylinders and the intersecting curve to help the welding-pool run smoothly.The BAMNP method can make sure the pose vertical to the curve and center between the two cylinders at the same time,therefore its performance in welding-technique is superior to the BAARP method.By using the traditional BAARP method,the robot structure can become simpler and easier to be controlled,because one degree of freedom(DOF) of the robot can be reduced.For the special case of perpendicular intersecting,an index is constructed to evaluate the quality of welding technique in the process of welding.The effect of different combination of pipe size on this index is also discussed.On the basis of practical consideration,selection principle for BAARP and BAMNP is described.The simulations of those two methods for a serial joint-type robot are made in MATLAB,and the simulation results are consistent to the analysis.The mathematical model and the proposed new pose-planning method will lay a solid foundation for future researches on the control and design of all-position welding robots. 展开更多
关键词 pose planning ROBOT all-position welding intersecting pipes bisecting angle welding quality
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MECHANICAL PROPERTIES OF LONGITUDINAL SUBMERGED ARC WELDED STEEL PIPES USED FOR GAS PIPELINE OF OFFSHORE OIL 被引量:10
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作者 Z.Z. Yang W. Tian +5 位作者 Q.R. Ma Y.L. Li J.K. Li J.Z. Gao H.B. Zhang Y.H. Yang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2008年第2期85-93,共9页
Since the development of offshore oil and gas, increased submarine oil and gas pipelines were installed. All the early steel pipes of submarine pipelines depended on importing because of the strict requirements of com... Since the development of offshore oil and gas, increased submarine oil and gas pipelines were installed. All the early steel pipes of submarine pipelines depended on importing because of the strict requirements of comprehensive properties, such as, anti-corrosion, resistance to pressure and so on. To research and develop domes- tic steel pipes used for the submarine pipeline, the Longitudinal-seam Submerged Arc Welded (LSAW) pipes were made of steel plates cut from leveled hot rolled coils by both the JCOE and UOE (the forming process in which the plate like the letter “J”, “C”, “0” or “U” shape, then expansion) forming processes. Furthermore, the mechanical properties of the pipe base metal and weld metal were tested, and the results were in accordance with the corresponding pipe specification API SPEC 5L or DNV- OS-FI01, which showed that domestic LSAW pipes could be used for submarine oil and gas pipelines. 展开更多
关键词 Mechanical properties Offshore oil and gas Longitudinal-seamsubmerged arc welded pipe (LSA W) pipeline JCOE formingprocess UOE forming process
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CONTRACTED EFFECT OF BELL-SHADE SHAPE WELDING ARC AND ACCOMPANIED MAGNETIC FIELD WITH SPIRAL PIPE SHAPE 被引量:4
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作者 Yu Jianrong, Zhang Jiaying , Jiang Lipei, Jiao Xiangdong Beijing Institute of Petrochemical Technology, Beijing 102600 Department of Mechanical Engineering,Tsinghua University, Beijing 100084 Jia Changshen, Shi Yaowu Xi′an Jiaotong University, 《中国有色金属学会会刊:英文版》 CSCD 1997年第2期96-99,共4页
CONTRACTEDEFFECTOFBELLSHADESHAPEWELDINGARCANDACCOMPANIEDMAGNETICFIELDWITHSPIRALPIPESHAPE①YuJianrong,ZhangJi... CONTRACTEDEFFECTOFBELLSHADESHAPEWELDINGARCANDACCOMPANIEDMAGNETICFIELDWITHSPIRALPIPESHAPE①YuJianrong,ZhangJiaying,JiangLipei,... 展开更多
关键词 longitudinal magnetic field BELL SHADE SHAPE welding arc contracted effect ACCOMPANIED magnetic field SPIRAL pipe SHAPE
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Quality Control on Crimping of Large Diameter Welding Pipe 被引量:3
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作者 FAN Lifeng GAO Ying +1 位作者 LI Qiang XU Hongshen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第6期1264-1273,共10页
Crimping is used in production of large diameter submerged-arc welding pipes. Many researches are focused on crimping in certain manufacturing mode of welding pipe. The application scopes of research achievements beco... Crimping is used in production of large diameter submerged-arc welding pipes. Many researches are focused on crimping in certain manufacturing mode of welding pipe. The application scopes of research achievements become limited due to lack of uniformity in theoretical analysis. In order to propose a crimping prediction method in order to control forming quality, the theory model of crimping based on elastic-plastic mechanics is established. The main technical parameters are determined by theoretical analysis, including length of crimping, base radius of punch, terminal angle of punch, base radius of die, terminal angle of die and horizontal distance between punch and die. In addition, a method used to evaluate the forming quality is presented, which investigates the bending angle after springback, forming force, straight edge length and equivalent radius of curvature. In order to investigate the effects of technical parameters on forming quality, a two-dimensional finite element model is established by finite element software ABAQUS. The finite element model is verified in that its shapes error is less than 5% by comparable experiments, which shows that their geometric precision meets demand. The crimping characteristics is obtained, such as the distribution of stress and strain and the changes of forming force, and the relation curves of technical parameters on forming quality are given by simulation analysis. The sensitivity analysis indicates that the effects of length of crimping, technical parameters of punch on forming quality are significant. In particular, the data from simulation analysis are regressed by response surface method (RSM) to establish prediction model. The feasible technical parameters are obtained from the prediction model. This method presented provides a new thought used to design technical parameters of crimping forming and makes a basis for improving crimping forming quality. 展开更多
关键词 welding pipe crimping forming forming quality control finite element analysis(FEA) response surface method(RSM)
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Finite element synthesized analysis of the forming process of spiral welded pipe 被引量:2
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作者 俞建荣 吴波 +3 位作者 赵增慧 凌星中 肖云峰 陈海洋 《China Welding》 EI CAS 2006年第4期71-74,共4页
Numerical simulation concerning the forming and welding process of spiral welded pipe was conducted, which included three steps : the first step was the stress analysis when the spiral was formed, and then the stress... Numerical simulation concerning the forming and welding process of spiral welded pipe was conducted, which included three steps : the first step was the stress analysis when the spiral was formed, and then the stress was regarded as initial condition of melding during the temperature field analysis in the process of welding, the last step was the thermal stress analysis of the weld seam after the welding was over. Moreover, when the steel strip was pushed, the stress was also calculated by non-linearity contact technology using Abaqus Software. By finite element modeling and calculating of the forming and welding process of the spiral welded pipe, the key points of the multi-fields synthetic simulating were studied and discussed. 展开更多
关键词 spiral welded pipe contact effect stress field temperature field finite element analysis
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Three-roller continuous setting round process for longitudinally submerged arc welding pipes 被引量:4
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作者 Xue-ying HUANG Jun ZHAO +3 位作者 Gao-chao YU Qing-dang MENG Zhen-kai MU Rui-xue ZHAI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第5期1411-1426,共16页
In order to solve the problems of excess ovality and cross-section distortion of longitudinally submerged arc welding pipes after forming,a new three-roller continuous setting round process was proposed.This process c... In order to solve the problems of excess ovality and cross-section distortion of longitudinally submerged arc welding pipes after forming,a new three-roller continuous setting round process was proposed.This process can be divided into three stages:loading stage,roll bending stage and unloading stage.Based on the discretization idea,the mechanical model of the primary statically indeterminate problem of the longitudinally submerged arc welding pipes at the roll bending stage was established,and the deformation response was obtained.The simulation and theoretical results show that there are three positive bending regions and three reverse bending regions along the circumference of the pipe.The loading force of each roller shows growth,stability and downward trend with time.The error between the theoretical fitting curve and the simulated data point is very small,and the simulation results verify the reliability of the theoretical calculation.The experimental results show that the residual ovality decreases with the increase of the reduction,and the reduction of the turning point is the optimum reduction.In addition,the residual ovality of the pipe is less than 0.7%without cross-section distortion,which verifies the feasibility of this process. 展开更多
关键词 longitudinally submerged arc welding pipes three-roller continuous setting round statically indeterminate problem mechanical model ovality optimum reduction
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Prediction of welding residual stress in multipass narrow gap welded pipes with large thickness 被引量:1
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作者 谭龙 张建勋 庄栋 《China Welding》 EI CAS 2014年第1期6-11,共6页
The objective of this study is to investigate the influence of post weld heat treatment (PWHT) on the distribution of residual stress in welded pipes with large thickness. The detailed pass-by-pass finite element si... The objective of this study is to investigate the influence of post weld heat treatment (PWHT) on the distribution of residual stress in welded pipes with large thickness. The detailed pass-by-pass finite element simulation was developed to study the residual stress in narrow gap multipass welding of pipes with a wall thickness of 150 mm and 89 weld beads. The effect of PWHT on welding residual stress was also investigated by means of numerical analysis. The simulated results show that the hoop stress is tensile stress in the weld region and compressive stress in the parent metal areas adjacent to weld seam. After heat treatment, the residual stresses decrease substantially, and the simulated residual stress is validated by the experimental one. The distribution of the through-wall axial residual stress along the weld center line is a self-equilibrating type. 展开更多
关键词 finite element analysis muhipass welding residual stress post weld heat treatment thick-walled pipe
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Research on technology of automatic welding machine and procedure for pile pipes of offshore jacket platform 被引量:3
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作者 Tang Deyu Feng Biao Li Chunrun Niu Huli Zhang Jianhu Long Bin Sun Bo 《Engineering Sciences》 EI 2010年第2期24-30,43,共8页
Because of the high requirement of quality,vile working environment and great difficulty of automatic welding,MMAW is usually adopted for the welding of the platform jacket and the pile pipe.Its low efficiency and har... Because of the high requirement of quality,vile working environment and great difficulty of automatic welding,MMAW is usually adopted for the welding of the platform jacket and the pile pipe.Its low efficiency and hard working is one of the choke points for construction progress. In this article,an up-to-date technology for platform pile pipe welding was introduced. Cored with FCW-S and combined with the characters and requirements of platform construction,the special automatic horizontal welding equipment and process were developed. Further more,the offshore application were introduced too. 展开更多
关键词 OFFSHORE jacket platform pile pipe automatic welding PLC
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Experimental and Simulation Studies on Cold Welding Sealing Process of Heat Pipes 被引量:4
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作者 Yong LI Shengle CHEN +2 位作者 Jinlong HUANG Yuying YAN Zhixin ZENG 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第2期332-343,共12页
Sealing quality strongly affects heat pipe performance, but few studies focus on the process of heat pipe sealing. Cold welding sealing technology based on a stamping process is applied for heat pipe sealing. The bond... Sealing quality strongly affects heat pipe performance, but few studies focus on the process of heat pipe sealing. Cold welding sealing technology based on a stamping process is applied for heat pipe sealing. The bonding mechanism of the cold welding sealing process (CWSP) is investigated and compared with the experimental results obtained from the bonding interface analysis. An orthogonal experiment is conducted to observe the effects of various parameters, including the sealing gap, sealing length, sealing diameter, and sealing velocity on bonding strength. A method with the utilization of saturated vapor pressure inside a copper tube is proposed to evaluate bonding strength. A corresponding finite element model is developed to investigate the effects of sealing gap and sealing velocity on plastic deformation during the cold welding process. Effects of various parameters on the bonding strength are determined and it is found that the sealing gap is the most critical factor and that the sealing velocity contributes the least effect. The best parameter combination (AIB3CID3, with a 0.5 mm sealing gap, 6 mm sealing length, 3.8 mm sealing diameter, and 50 mm/s sealing velocity) is derived within the experimental parameters. Plastic deformation results derived from the finite element model are consistent with those from the experiment. The instruction for the CWSP of heat pipes and the design of sealing dies of heat pipes are provided. 展开更多
关键词 Cold welding sealing process(CWSP) · Bonding strength · Heat pipe · Orthogonal experimen
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Hot-rolled strips of up to 19 mm in thickness and their processing to helically welded large diameter pipes of grade X80 被引量:1
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作者 Volker FLAXA Franz Martin KNOOP 《Baosteel Technical Research》 CAS 2010年第S1期56-,共1页
Hot-rolled wide strip for production of large diameter,heavy gauged(up to 19 mm) helical line pipe grade X80 was a priority development over the last three years.Microstructure,texture and mechanical properties of str... Hot-rolled wide strip for production of large diameter,heavy gauged(up to 19 mm) helical line pipe grade X80 was a priority development over the last three years.Microstructure,texture and mechanical properties of strips have been characterised.Also the welding conditions have been simulated.The favourable microstructure is achieved by the proper selection of an appropriate chemical composition of low carbon content and increased niobium micro alloying in combination with suitable strictly controlled hot-rolling parameters.The addition of niobium in combination with the adjustment of other alloying elements increases the recrystallisation stop temperature and thus makes it possible to apply a high temperature processing(HTP) concept.The homogeneous bainitic microstructure across the strip gauge is then formed during accelerated cooling on the run-out table of the hot-rolling mill.All results indicated excellent properties of these hot strips which make it suitable for spiral pipes of grade X80 for example 18.9mm×Φ1 220 mm at dimension. 展开更多
关键词 hot-rolled strip helically welded pipe X80 up to 19 mm wall thickness salzgitter
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Cold welding sealing of copper-water micro heat pipe ends 被引量:3
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作者 汤勇 陆龙生 +1 位作者 邓大祥 袁冬 《中国有色金属学会会刊:英文版》 CSCD 2009年第3期568-574,共7页
The quality of micro heat pipe(MHP) is strongly affected by sealing technology. Based on the analysis of requirements of sealing technology, a cold welding technology was presented to seal MHP. In the cold welding pro... The quality of micro heat pipe(MHP) is strongly affected by sealing technology. Based on the analysis of requirements of sealing technology, a cold welding technology was presented to seal MHP. In the cold welding process, compression force was used to flatten micro groove copper(MGC) tube. Then the bonding of MGC tube was reached because of intensively plastic deformation of MGC tube under pressure. It is found that the plastic deformation area of the cold welding of MGC tube can be divided into three sections. The deformation of micro grooves in each section was investigated; the influence of the dimensions of cylindrical heads on the weld joint shape and strength was studied; and a comparison between smooth copper tube and MGC tube was done. The results show that a groove compression stage exists in the cold welding of MGC tube besides a flattened stage and a melting stage. 展开更多
关键词 密封技术 微型热管 铜管 冷焊 塑性变形 MGC 焊接技术 焊接工艺
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Transient out-of-plane distortion of multi-pass fillet welded tube to pipe T-joints
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作者 R.Vetriselvan K.Devakumaran +1 位作者 P.Sathiya G.Ravichandran 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2017年第2期77-85,共9页
The out-of-plane distortion induced in a multi-pass circumferential fillet welding of tube to pipe under different weld sequences and directions was studied using Finite Element Method(FEM) based Sysweld software and ... The out-of-plane distortion induced in a multi-pass circumferential fillet welding of tube to pipe under different weld sequences and directions was studied using Finite Element Method(FEM) based Sysweld software and verified experimentally. The FEM analyses consisted of thermal and mechanical analyses.Thermal analysis was validated with experimental transient temperature measurements. In the mechanical analysis, three different weld sequences and directions were considered to understand the mechanism of out-of-plane distortion in the tube to pipe T-joints. It was learnt that the welding direction plays a major role in minimizing the out-of-plane distortion. Further, during circumferential fillet welding of the tube to pipe component, the out-of-plane distortion generated in the x direction was primarily influenced by heat input due to the start and stop points, whereas the distortion in the z direction was influenced by time lag and welding direction. The FEM predicted distortion was compared with experimental measurements and the mechanism of out-of-plane distortion was confirmed. 展开更多
关键词 MULTI-PASS welds FEM Temperature field OUT-OF-PLANE DISTORTION TUBE to pipe T-JOINTS Circumferential welding
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Comparative study of weld residual stress on steel pipes with different weld types
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作者 Luo Yun Zhang Xiaolei +1 位作者 Jiang Wenchun Hao Muming 《China Welding》 EI CAS 2016年第4期52-60,共9页
This study developed a sequential coupling finite element procedure to predict residual stresses of steel pipes with longitudinal wela/ circumferential weld and spiral weld.The results show that the residual stress i... This study developed a sequential coupling finite element procedure to predict residual stresses of steel pipes with longitudinal wela/ circumferential weld and spiral weld.The results show that the residual stress in heat affected zone(HAZ)is higher than that in weld for spiral weld pipe.For the circumferential weld pipe and spiral weld pipe,the residual stress in inner surface is higher than that in outer surface.However,for the spiral weld pipe,the residual stress in inner surface is smaller than that in outer surface.The hoop residual stress of circumferential weld pipe is higher than that of longitudinal weld pipe,while the axial residual stress of circumferential weld pipe is smaller than that of longitudinal weld pipe.The hoop stresses for circumferential weld pipe and axial stress for longitudinal weld pipe have exceeded the yield strength of base metal.With the increase of helix angle,the hoop stress decreases while the axial stress increases.For the spiral pipe(α=30° to 50°),both the hoop stress and axial stress are relatively small.The spiral pipe(helix angle ranging from 30° to 50°) is helpful to reduce stress corrosion cracking(SCC) and it is recommended to manufacture the steel pipe. 展开更多
关键词 steel pipe residual stress longitudinal weld circumferential weld spiral weld
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Girth welding procedure and weldability evaluation of coal seam gas transmission UOE pipeline
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作者 LIU Shuo QIAN Weifang +1 位作者 WANG Huailong CAO Neng 《Baosteel Technical Research》 CAS 2013年第3期36-41,共6页
According to the requirements of Queensland Gas Company Ltd. (QGC), the operator of the Queensland Curtis LNG (QCLNG) pipeline project in Australia, girth welding experiments and weldability evaluations have been ... According to the requirements of Queensland Gas Company Ltd. (QGC), the operator of the Queensland Curtis LNG (QCLNG) pipeline project in Australia, girth welding experiments and weldability evaluations have been carded out for three X70 UOE pipes from Baosteel based on API 1104 standards. Shielded metal arc welding (SMAW) and gas- shielded flux-cored wire arc welding (FCAW-G) have been applied, and the girth weld joint quality and mechanical performance were evaluated. It was found that the field girth weldability of Baosteel' s XT0 UOE pipes was excellent under the conditions used here and satisfied the requirements of the QCLNG project for field girth welding construction. Furthermore,Baosteel has offered a solution to the QCLNG project for pipeline girth welding in which the girth welding joint design, selection of welding processes and consumables, welding procedures, techniques and joint inspections are included. Such research provides important guidance for the difficult tie-in welding applications for the construction of the QCLNG pipelines in the field. 展开更多
关键词 coal seam gas UOE pipe girth weld weldABILITY welding procedure tie-in welding
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Elevated temperature strain softening characteristics of 12Cr1MoV steel friction welding pipe joints
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作者 YANG Dexin ZHAO Xiujuan +1 位作者 LIU Zhiquan CHEN Chunhuan and LUO Yu (Welding Department of Dalian Railway Institute. Dalian. 116028.) 《China Welding》 EI CAS 1996年第1期66-70,共5页
The strain softening characteristics analysis of 12Cr1MoV streel friction welding pipe joints.which were removed from heating apparatus pipes ager over 9 and is yearly of service, was undertaken. It is concluded that ... The strain softening characteristics analysis of 12Cr1MoV streel friction welding pipe joints.which were removed from heating apparatus pipes ager over 9 and is yearly of service, was undertaken. It is concluded that the evident softening did not occur in the weld metal and HAZ during serice. whereas it did in the base metal 2mm apart from the center of the weld metal. The difference is due to the restriction of the pipe hoop, which is formed on the joint during friction welding. The bainite. microstructure in the weld metal and HA Z, which is harder than the pearlite, pecrostpucture in the base metal, makes contpibution too. ThIS phenomenon is peculiar to the friction weldings pipes. 展开更多
关键词 strain softening boiler pipes CREEP friction welding
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Effect of strength matching on the reliability of welded pipe with circumferential surface crack
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作者 何柏林 于影霞 +1 位作者 霍立兴 张玉凤 《China Welding》 EI CAS 2004年第2期106-110,共5页
For different strength matching, the reliability index and failure probability of welded pressure pipe with circumferential surface crack were calculated using three dimensional stochastic finite element method. This ... For different strength matching, the reliability index and failure probability of welded pressure pipe with circumferential surface crack were calculated using three dimensional stochastic finite element method. This method has overcome the shortcomings of conservative results in safety assessment with deterministic fracture mechanics method. The effects of external moment and the depth of the circumferential surface crack (a) on the reliability of pressure pipe were also calculated and discussed. The calculation results indicate that the strength matching has certain effect on the reliability of the welded pressure pipe with circumferential surface crack. The failure probability of welded pressure pipe with high strength matching is lower than that with low strength matching at the same conditions. The effects of strength matching on the failure probability and reliability index increased by adding external moment (M) and the depth of the circumferential surface crack (a). 展开更多
关键词 welded pressure pipe RELIABILITY CRACK strength matching stochastic finite element method
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Mathematical modeling and simulation application for a wheeled mobile robot applied on pipe welding
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作者 薛杨 黄军芬 +1 位作者 黄继强 张翔 《China Welding》 EI CAS 2015年第3期52-57,共6页
A geometric model was built to represent the position relation of a wheeled mobile robot relative to a pipe. The relationship between the deviation of falling off for the robot and the curvature of the pipe was formul... A geometric model was built to represent the position relation of a wheeled mobile robot relative to a pipe. The relationship between the deviation of falling off for the robot and the curvature of the pipe was formulated quantitatively. Based on the relationship, a mathematical model was derived and a fuzzy control algorithm for the robot was developed. Simulations were carried out to confirm the dynamic index and the validity of the mathematical model of the fuzzy control algorithm for seam tracking of pipe welding. Experiments for pipe welding with the mobile robot were also carried out to verify the algorithm, and the results showed that the seam has a good quality with a preferable appearance of weld. 展开更多
关键词 wheeled mobile robot pipe welding deviation of falling off
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Study of relieving weld residual stresses in large pressure steel pipes of hydropower station by local explosion treatment
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作者 Zhu Shichang Chen Liangshan +2 位作者 Dong Xiuzhong Chen Huaining and Wang Yanyan(Institute of Metal Research, Academia Sinica, Shenyang) Tan Shenyu Huang Baoming and Chui Guangyuan(Shenyang Institute of Artillery) 《China Welding》 EI CAS 1995年第1期44-50,共7页
From comparing the test of local explosion treatment(LET)with the locaf heat treatment (LHT)in welded plates and welded steel pipes in field,LET has excellent effect of stress relief and high efficiency. Whereas the e... From comparing the test of local explosion treatment(LET)with the locaf heat treatment (LHT)in welded plates and welded steel pipes in field,LET has excellent effect of stress relief and high efficiency. Whereas the effect of stress relief for LHT with 575℃×1.5hr is poor.The mechanical properties of welded joints after LET are basically the same as those of as-welded joints.The practically measuring results on 4 large steel-pipe surfaces indicate that the welding residual tensile stresses in welds,which mostly is compression residual stress,are basically relieved. 展开更多
关键词 pressure steel pipe explosion treatment welding residual stress
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