Large Deformation Analysis of an Elastic-Plastic Cantilevered Beam

Abstract

This study concerns the analysis of the deflection of an elastic-plastic cantilevered beam. Three regions of solution are treated: (i) purely elastic response at low loads; (ii) elastic-plastic response without a hinge, for intermediate loads; and (iii) elastic-plastic response with a hinge for loads corresponding to the fully plastic bending moment at the built-in end. Most existing solutions for this type of problem involve various approximations avoided here, for example, ignoring the elastic part of the strain or using upper bounds based on limit analysis. By avoiding such approximations, the solution given here may be useful as a benchmark for validating finite element codes in the large deformation elastic-plastic regime. Several aspects of the solution are analyzed: (i) the load-deflection relation; (ii) the growth of the elastic-plastic zone; (iii) limiting cases; (iv) the residual configuration; (v) the small bending configuration. A numerical procedure based on Runge-Kutta methods is used, leading to the load-deflection relation in graphical form.