Welding deformations can be predicted by inherent strains that are assumed to be distributed in the welds and nearby area. This method is more convenient compared with the thermo elasto plastic finite element method b...Welding deformations can be predicted by inherent strains that are assumed to be distributed in the welds and nearby area. This method is more convenient compared with the thermo elasto plastic finite element method because only elastic analysis is necessary. The problem is how to know the inherent strains in advance during deformation analysis. The relations between inherent strains and welding parameters based on some experimental curves and a 3 D FEM model were introduced. According to this study, the longitudinal and transverse inherent strains that are the most important factors on welding deformations can be determined. The effectiveness of the proposed methods is demonstrated through the deformation analysis of a large welded cylinder with multipass welds as an example.展开更多
It has been widely studied about the final residual stress and deformation in muhipass welding of thick weldments. But there is a lack of a clear understanding of the interrelationship of interpass stress and deformat...It has been widely studied about the final residual stress and deformation in muhipass welding of thick weldments. But there is a lack of a clear understanding of the interrelationship of interpass stress and deformation during multipass welding. In this study, a three dimension numerical model of a sixteen-pass double V-groove welded joint with 50 mm plate is developed to compute the stress field and deformation by using multiple CPU parallel processing technology. The following factors such as the non-linear of temperature, heat radiation, filling of material step by step and so on are considered. Distribution and evolution law of welding stress in the transverse and longitudinal section is analyzed in this paper, and the interpnss stresses are studied also. At the same time the evolution course of angular deformation amount is analyzed, and the experimental results show that the calculated resuhs accord with the measured results of angular deformation.展开更多
运用光学显微镜和扫描电镜研究了SA203Gr.D钢焊接接头的组织和二次电子像,通过裂纹扩展性试验(Crack Tip Opening Displacement)观察焊缝区的断裂力学性能,并采用盲孔法测试得到了不同区域的残余应力分布。试验结果为SA203Gr.D钢的焊接...运用光学显微镜和扫描电镜研究了SA203Gr.D钢焊接接头的组织和二次电子像,通过裂纹扩展性试验(Crack Tip Opening Displacement)观察焊缝区的断裂力学性能,并采用盲孔法测试得到了不同区域的残余应力分布。试验结果为SA203Gr.D钢的焊接制造提供了重要的参考依据。展开更多
Two main methods, inactive eiement method and quiet element method, to simulate the process of multilayer ：and multipass welding：were reviewed, and the shortcomings of both methods were diScussed as well Based on ...Two main methods, inactive eiement method and quiet element method, to simulate the process of multilayer ：and multipass welding：were reviewed, and the shortcomings of both methods were diScussed as well Based on these analyses, a method called node dynamic relaxation method was put into forward to simulate the multilayer and multipass welding process, and the principle and application of this method were discussed in detail. The simulating results show that using the node dynamic relaxation method can decrease mesh distortion, improve calculation efficiency, and obtain good simulation results. This method can also be used in the field of simulation addition or removing materials in finite element analysis.展开更多
基金National Natural Science Foundation ofChina!( No. 592 752 0 3)
文摘Welding deformations can be predicted by inherent strains that are assumed to be distributed in the welds and nearby area. This method is more convenient compared with the thermo elasto plastic finite element method because only elastic analysis is necessary. The problem is how to know the inherent strains in advance during deformation analysis. The relations between inherent strains and welding parameters based on some experimental curves and a 3 D FEM model were introduced. According to this study, the longitudinal and transverse inherent strains that are the most important factors on welding deformations can be determined. The effectiveness of the proposed methods is demonstrated through the deformation analysis of a large welded cylinder with multipass welds as an example.
基金National Natural Science Foundation of China (No. 50775053, 50675046)
文摘It has been widely studied about the final residual stress and deformation in muhipass welding of thick weldments. But there is a lack of a clear understanding of the interrelationship of interpass stress and deformation during multipass welding. In this study, a three dimension numerical model of a sixteen-pass double V-groove welded joint with 50 mm plate is developed to compute the stress field and deformation by using multiple CPU parallel processing technology. The following factors such as the non-linear of temperature, heat radiation, filling of material step by step and so on are considered. Distribution and evolution law of welding stress in the transverse and longitudinal section is analyzed in this paper, and the interpnss stresses are studied also. At the same time the evolution course of angular deformation amount is analyzed, and the experimental results show that the calculated resuhs accord with the measured results of angular deformation.
文摘Two main methods, inactive eiement method and quiet element method, to simulate the process of multilayer ：and multipass welding：were reviewed, and the shortcomings of both methods were diScussed as well Based on these analyses, a method called node dynamic relaxation method was put into forward to simulate the multilayer and multipass welding process, and the principle and application of this method were discussed in detail. The simulating results show that using the node dynamic relaxation method can decrease mesh distortion, improve calculation efficiency, and obtain good simulation results. This method can also be used in the field of simulation addition or removing materials in finite element analysis.
