Limit Load of Anisotropic Components Using the M-Beta Multiplier Method

Abstract

The mβ-multiplier method is based on Mura’s extended variational theorems in plasticity, and has been applied previously to isotropic components containing notches and cracks. Lower bound limit loads rapidly converge to inelastic analysis results when the method is used in conjunction with elastic modulus adjustment procedures. In this paper, the mβ-multiplier method is applied to pressure components exhibiting anisotropy. Specifically, the method is applied to the limit load determination of a heat exchanger tubesheet, wherein the tubesheet is modeled as an equivalent solid plate with anisotropic properties. Results are presented for a finite element model where plasticity is represented with Hill’s yield criterion, and a model using a fourth order yield criterion that accounts for compressibility of the tubesheet.