Elastic-Plastic Stress Analysis of Thermoplastic Matrix Laminated Composite Beams

This study deals with an elastic-plastic behavior of woven steel fibers reinforced thermoplastic matrix laminated composite beam subjected to a bending moment. The beam consists of symmetric four orthotropic layers and its material is assumed to be strain hardening. The Tsai-Hill theory is used as a yield criterion in the solution. The Bernoulli-Euler hypotheses are utilized for small plastic deformations. The beam lay-up sequences are chosen as [0°]₄, [15°/-15°]_s, [30°/-30°]_s and [45°/-45°]_s. The bending moment values that begin plastic flow at the upper and lower surfaces of the beam are carried out for various stacking sequences. The variations of the elastic, elastic-plastic and residual stress components versus increasing plastic region spread are given in tables and figures. The transverse displacement is obtained at the free end, numerically.