Limit load estimation using plastic flow parameter in repeated elastic finite element analyses

The procedures described in this paper for determining a limit load is based on Mura's extended variational formulation. Used in conjunction with linear elastic finite element analyses, the approach provides a robust method to estimate limit loads of mechanical components and structures. The secant modulus of the various elements in a finite element discretization scheme is prescribed in order to simulate the distributed effect of the plastic flow parameter, μ 0 . The upper and lower-bound multipliers m° and m' obtained using this formulation converge to near exact values. By using the notion of leap-frogging to limit state, an improved lower-bound multiplier, m α , can be obtained. The condition for which m α is a reasonable lower bound is discussed in this paper. The method is applied to component configurations such as cylinder, torispherical head, indeterminate beam, and a cracked specimen.