Numerical and analytical study on deep biaxial bending collapse of thin-walled beams

The objective of the paper is to get a fundamental understanding of large r otation response of thin-walled prismatic beams subjected to biaxial bendin g. Square and rectangular section beams were subjected to a cantilever bend ing with hinge rotation up to 40 degrees. A general purpose nonlinear FE co de PAM-CRASH was used to generate results. Altogether 94 computer runs were made by changing aspect ratio, condition of the loading and bending plane with respect to principal inertia axes of the cross section. The main empha sis was placed on the determination of initial and subsequent yield loci. I t was also shown that the direction of the vector of generalized strain rat es obeys the normality rule. Calculated in the paper was also a critical an gle defining a preferable direction of bending. The present finding can be used to better interpret results of FE calculation of automotive bodies and to develop simplified crash-oriented design tools. (C) 2000 Elsevier Scien ce Ltd. All rights reserved.