Initiation and growth of buckling in the biaxial diagonal tensile test on steel sheet

Abstract

Initiation and growth of buckling, a main cause of surface deflection in large steel press-formed components such as automobile outer panels, is simulated by the biaxial diagonal tensile test on square steel sheet specimens. The effects of the properties of the steel sheets and the biaxial loading conditions on the initiation and growth of buckling are examined by the tests and by FEM analysis. It is found that both the initiation and the growth of buckling are strongly affected by the yield strength of the material, σ s, and by the tensile stress in the breadth direction, p Y , and that buckling is restrained when p Y / σ s is high: this is because the compressive stress at the center of the specimen, the compressive stress area, and the development of the buckling area are largely affected by these factors.