An elastic-plastic stress analysis of woven Ni-Cr reinforced thermoplastic composite cantilever beam

In the present study an analytical elastic-plastic stress analysis is carried out for a low-density homogeneous polyethylene thermoplastic cantilever beam reinforced by Ni-Cr steel fibers. The beam is loaded by a constant single force at its free end. The expansion of the region and the residual stress component of sigma(x), are determined for 0 degrees, 15 degrees, 30 degrees and 45 degrees orientation angles. For 0 degrees and 45 degrees orientation angles yielding begins at the upper and lower surfaces of the beam, at the same distances from the free end. However, for 15 degrees and 30 degrees orientation angles it starts first at the upper surface. The elastic-plastic analysis is carried out for both the plastic region which spreads only at the upper surface and the plastic region which spreads at the upper and lower surfaces together. The,residual stress components of sigma(xy) and tau(xy) are also determined. The intensity of the residual stress component is maximum at the upper and lower surfaces of the beam, but the residual stress component of tau(xy) is maximum on or around the x-axis. The beam can be strengthened by using the residual stresses. The distance between the plastically collapsed point and the free end is calculated for the same load in the beam for 0 degrees, 15 degrees, 30 degrees and 45 degrees orientation angles.