Investigation of defect behavior during the stamping of a thin-walled semicircular shell with bending angle

Springback, wrinkling, and thinning typically occur during the stamping of thin-walled semicircular shells with bending angle. These defects cause poor forming accuracy of specimens and lead to assemble difficultly; consequently, the produced specimens do not meet requirements. In this work, the defect behavior during the stamping of thin-walled semicircular shells with bending angle is studied via an analytical model, experiments, and finite element (FE) simulation. First, an analytical model is established to predict springback and analyze springback trend. Second, stamping experimental tests of a thin-walled semicircular shell with bending angle are conducted. The influences of blank holder force (BHF) and stamping speed on the springback, wrinkling, and thinning of specimens are investigated. Finally, an FE simulation model is developed to investigate the deformation characteristics and springback of the thin-walled semicircular shell with bending angle. Results show that the maximum springback decreases with increasing BHF. Meanwhile, the results of the analytical model are consistent with the experimental and simulation results. The maximum thinning rate of the specimen increases with increasing BHF, whereas the wrinkling defect exhibits the opposite trend. The maximum thinning rate and wrinkling of the specimen increase with increasing stamping speed. Compared with that of BHF, the effect of stamping speed on defects is smaller.