Plastic interaction relations for hollow structural steel sections.

Abstract

The first part of this study reports an experimental program consisting of six full-scale tests on pipe sections under load combinations of shearing forces, bending moments, and twisting moments. The experimental results agree very well with the predicted failure loads based on recently developed interaction relations. The experimental program establishes the validity of the analytical techniques used to derive the interaction relations for pipe sections. The verified methodology is extended to derive interaction relations for square hollow structural sections under combinations of normal forces, twisting moments, biaxial bending moments, and biaxial shearing forces. Careful consideration is given to the applicability limits of the developed interaction relations. A stress resultant transformation scheme is devised in order to reduce the number of interaction relations from 20 cases to only three fundamental cases.