Evaluation of Press Forming Technique for Bent Automotive Body Parts Using In-Plane Shear Deformation

Abstract

AbstractA basic evaluation of a new press forming technique using in-plane shear deformation was carried out to suppress fracture and wrinkle of parts bent in the height direction, supposing auto body parts such as the front side member rear. This two-step technique comprises two processes. The first process is deep draw forming with a rectangular blank to induce in-plane shear strain in the blank. The second process is bending the pre-formed blank into a part shape with a U-shaped cross section. According to experiments, in-plane shear deformation was induced in the blank in the first process when the press stroke changed along the part longitudinal direction, and increasing the induced in-plane shear deformation made it possible to form a part with a higher bent angle in the height direction in the second process. The results suggested that complex bent parts which were difficult to form by the conventional press forming technique can be formed without fracture or wrinkle when appropriate in-plane shear deformation is induced in the blank in the first process.KeywordsPress forming techniqueIn-plane shear deformationPre-forming