An Elastic-Plastic Stress Analysis of Simply Supported Thermoplastic Composite Beams Under a Transverse Uniformly Distributed Load

Abstract

An analytical elastic-plastic stress analysis is carried out on thermoplastic composite beams supported from two ends under transverse uniformly distributed load. The composite beams consist of woven steel fiber and thermoplastic matrix. The material is assumed to be perfectly plastic for the elastic-plastic solution. The intensity of the uniform force is chosen at a small value; therefore the normal stress components of σ y is neglected during the elastic-plastic solution. The expansion of the plastic region and the residual stress component of σ x are determined for 0°, 15°, 30° and 45° orientation angles. Plastic yielding occurs first 0° and 45° orientation angles on the lower and upper surfaces of the beam at the same distances from the ends. However; it starts first at the lower surface for 15°, 30° orientation angles. The intensity of the residual stress component of σ x is found to be maximum at the lower and upper surfaces; whereas the intensity of residual stress component τ xy is maximum on or around the x axis of the beam.