An Elasto-Plastic Stress Analysis in a Polymer Matrix Composite Beam of Arbitrary Orientation Subjected to Transverse Uniformly Distributed Load

Polymer matrix composite beam of arbitrary orientation subjected to transverse uniformly distributed load is studied by an analytical elasto-plastic stress analysis. In the elasto-plastic solution, the material is assumed to be perfectly plastic. A composite consisting of fiber reinforced polymer matrix was produced for this work. The expansion of the plastic region and the residual stress component of are determined for 0°, 30°, 45°, 60° and 90° orientation angles. The yielding begins for 0° and 90° orientation angles at the upper and lower surfaces of the beam at the same distances from the free end. But, it starts first at the upper surface for 30°, 45° and 60° orientation angles. Sample problems are given for various orientation angles, x axis of the beam is used to obtain the location of the elasto-plastic boundary and to calculate elastic, elasto-plastic and residual normal and shear stresses. The intensity of the residual stress component of τ_xy is maximum on or around the x axis of the beam but the residual stress component of σ_x is maximum at the upper and lower surfaces.