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
Residual stress is very important for the study of cardiovascular-relevant issues,such as assessing the vulnerability of atherosclerosis and aneurysm.In this paper,the circumferential residual stress of porcine aorta ...Residual stress is very important for the study of cardiovascular-relevant issues,such as assessing the vulnerability of atherosclerosis and aneurysm.In this paper,the circumferential residual stress of porcine aorta was characterized by combining ex vivo experiments with numerical studies.In the experiments,porcine aortic rings were prepared and cut open,and the cross sections of the opened aortic rings were extracted to construct finite element models.The 5-parameter Mooney-Rivlin model was chosen to describe the tensile mechanical behavior of the aorta.In numerical studies,based on the finite element models and hyperelastic material model,a pulling-back displacement was applied to reclose the models of the opened aortic rings,and the equivalent circumferential residual stress to the pre-opened aorta was analyzed.The results showed that the circumferential residual stress of the aorta generally decreased from the proximal to the distal ends,and the residual stresses of the aortic rings close to the distal end did not show a great difference.This work provides an improved understanding of the residual stress distribution in aorta and may be used as a more realistic initial condition for future stress analysis of the arterial tissue.展开更多
基金supported by the Taishan Scholar Construction Funding(ts201511018)the National Natural Science Foundation of China(11372359)+2 种基金the Natural Science Foundation for Distinguished Young Scholars of Shandong Province(JQ201417)the Fundamental Research Funds for the Central Universities(15Cx08006A)the Innovation Project Foundation for Graduate Student of China University of Petroleum(YCXJ2016029)
文摘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.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.11772093,11972118,61821002)Australian Research Council(ARC)(Grant No.DP200103492).
文摘Residual stress is very important for the study of cardiovascular-relevant issues,such as assessing the vulnerability of atherosclerosis and aneurysm.In this paper,the circumferential residual stress of porcine aorta was characterized by combining ex vivo experiments with numerical studies.In the experiments,porcine aortic rings were prepared and cut open,and the cross sections of the opened aortic rings were extracted to construct finite element models.The 5-parameter Mooney-Rivlin model was chosen to describe the tensile mechanical behavior of the aorta.In numerical studies,based on the finite element models and hyperelastic material model,a pulling-back displacement was applied to reclose the models of the opened aortic rings,and the equivalent circumferential residual stress to the pre-opened aorta was analyzed.The results showed that the circumferential residual stress of the aorta generally decreased from the proximal to the distal ends,and the residual stresses of the aortic rings close to the distal end did not show a great difference.This work provides an improved understanding of the residual stress distribution in aorta and may be used as a more realistic initial condition for future stress analysis of the arterial tissue.
