FEM and Experimental Studies on Profile Stretch-wrap Bending with Inner Pressure
Cross section distortion of profile occurring in the stretch-wrap bending process is one of main factors influencing the forming precision and must be minimized by some technical methods to cope with the high forming precision requests of Aluminum Space Frame (ASF). A numerical and experimental study on the stretch-wrap bending process with inner pressure is carried out to detect the effect of inner pressure on decreasing cross section distortion. FEM study is first presented to predict the magnitude of inner pressure enough to overcome the cross section distortion and the risk of fracture of the profile. Then an experimental test is conducted and the effect of inner pressure on cross section distortion and springback is gotten. The study shows that this forming method not only has the advantages of traditional stretch-wrap bending method, but also can get bended profiles with high section shape precision with even lower inner pressure. Also the forming method has the advantage of simpleness, low cost and easiness to be carried out, as the pressure is lower compared with hydroforming.
Xian-Bin ZHOU, Ke-Shan DIAO, Chao-Hai JIN, Xiao-Xing LI, Bernard CRIQUI
Stretch-wrap Bending, Aluminum Profile, FEM, Cross Section Distortion, Inner Pressure, Springback, Car Body Frame Structure.