An integrated load increment method for finite elasto–plastic stress analysis

Abstract

SUMMARYA new computational scheme, named the 'Integrated Load Increment' method (ILI), has been developed to handle elasto-plastic analysis of solids by the finite element variational technique. This scheme allows considerably larger loading steps to be applied to the structure without deviating from its nonlinear, load-deformation relationship. It has been shown that these relationships can be evaluated by integrating the nonlinear constitutive equations within each load increment under certain conditions. A numerical example on a pressurized thick-walled. cylinder indicates that a 240 per cent improvement in computational efficiency and substantial reduction of loading steps over the conventional load incremental method can be achieved by the ILI technique.

Stress Characterization of Autofrettaged Thick-Walled Cylinders

“…The method was found to result in a 240% improvement in computational efficiency and a substantial reduction in the number of load steps. The applicability of the isoparametric elements and the order of computation times involved have also been studied for three-dimensional FEM elastic-plastic problems [26]. The conventional FEM has been found to be weak in predicting surface stresses, where phenomena of interest usually occur.…”

Instability load analysis of a telescopic boom for an all-terrain crane

“…Second, the traditional load increment method needs to set a fixed load increment in the process of calculating the nonlinear equilibrium equations to obtain the structural equilibrium path (Wang et al, 2017). If the fixed increment is set too small, it will increase the calculation amount and reduce the calculation efficiency (Cheng et al, 1980). If the increment is too large, then the convergence may fail.…”