Effects of material property stratification and residual stresses on single angle flexural ductility

Abstract

This paper investigates the influences that non-homogeneous material properties and residual stress distributions have on the structural ductility of single angle beams bent about the minor principal axis. Such non-homogeneity in material response, and initial stress distribution results from manufacturing processes and varies substantially on a case-by-case basis. The investigation reported herein is based on experimentally verified nonlinear finite element modeling techniques. Mild carbon steel single angles with three distinct material property stratification scenarios are studied within the context of minor principal axis flexure. These cases are also examined both with and without the presence of residual stresses. Both plastic hinge rotation capacity and severity of unloading within the moment–rotation response are studied; in this way it is possible to quantify the structural ductility of single angle beams. In addition, differing definitions for plastic section properties are examined to ascertain their impact on the values of the above ductility response measures.