Thermo-mechanical simulations of single butt welding were performed ,for CLAM steel, utilizing commercial software, ANSYS, in which double ellipsoid heat source model was introduced and phase transition action was pre...Thermo-mechanical simulations of single butt welding were performed ,for CLAM steel, utilizing commercial software, ANSYS, in which double ellipsoid heat source model was introduced and phase transition action was precluded. The residual stress distributions based on the calculated temperature field were calculated and ahnost coincided with those from the experimental results. Based on the simulation, it was also found that tensile stress exists in the partial melting region and bond area; whilst compressive stress turns on away from weld zone. The residual stress over the cross section is very little and it is also confirmed to be tensile stress.展开更多
The ring expansion procedures over various forming velocities are calculated with ANSYS software in order to show the effect of forming velocity on ductility of rate insensitive materials. Ring expansion procedures ar...The ring expansion procedures over various forming velocities are calculated with ANSYS software in order to show the effect of forming velocity on ductility of rate insensitive materials. Ring expansion procedures are simplified to one-dimensional tension by constraining the radial deformation, with element birth and death method, fracture problem of circular ring are considered. The calculated results show that for insensitive materials of 1060 aluminum and 3A21 aluminum alloy, fracture strain increases corresponding to the increase of forming velocity. This trend agrees well with experimental results, and indicates inertia is the key factor to affect ductility; With element birth and death methods, fracture problems can be solved effectively. Experimental studies on formability of tubular workpieces are also conducted, experimental results show that the formability of 1060 aluminum and 3A21 aluminum alloy under electromagnetic forming is higher than that under quasistatic forming, according to the characteristics of electromagnetic forming, the forming limit diasrams of the two materials tube are also built respectively, this is very important to promote the development of electromagnetic forming and guide the engineering practices.展开更多
文摘Thermo-mechanical simulations of single butt welding were performed ,for CLAM steel, utilizing commercial software, ANSYS, in which double ellipsoid heat source model was introduced and phase transition action was precluded. The residual stress distributions based on the calculated temperature field were calculated and ahnost coincided with those from the experimental results. Based on the simulation, it was also found that tensile stress exists in the partial melting region and bond area; whilst compressive stress turns on away from weld zone. The residual stress over the cross section is very little and it is also confirmed to be tensile stress.
文摘The ring expansion procedures over various forming velocities are calculated with ANSYS software in order to show the effect of forming velocity on ductility of rate insensitive materials. Ring expansion procedures are simplified to one-dimensional tension by constraining the radial deformation, with element birth and death method, fracture problem of circular ring are considered. The calculated results show that for insensitive materials of 1060 aluminum and 3A21 aluminum alloy, fracture strain increases corresponding to the increase of forming velocity. This trend agrees well with experimental results, and indicates inertia is the key factor to affect ductility; With element birth and death methods, fracture problems can be solved effectively. Experimental studies on formability of tubular workpieces are also conducted, experimental results show that the formability of 1060 aluminum and 3A21 aluminum alloy under electromagnetic forming is higher than that under quasistatic forming, according to the characteristics of electromagnetic forming, the forming limit diasrams of the two materials tube are also built respectively, this is very important to promote the development of electromagnetic forming and guide the engineering practices.