Piecewise-Linear Yield Loci of Angle-Ply Reinforced Medium of Different-Resisting Rigid-Plastic Materials at 2D Stress State

The structural model of hybrid composites angle-ply that were reinforced parallel to some plane is constructed for the analytical determination of the composition’s yield loci while considering the plane stress state in all components. The materials of the components are homogeneous and isotropic, as well as have different yield strengths in tension and compression. Their mechanical behavior is described by the associated flow law for a rigid-plastic body with the piecewise-linear yield conditions of Johansen, Tresca, Hu, and Ishlinsky–Ivlev. The cases of fiber placement along the trajectories of the principal stresses in the composition and the cases of angle-ply reinforcement symmetric with respect to these trajectories are considered. The influence of the reinforcement structure (of directions and densities) on the size and shape of the yield loci of compositions is investigated. It is shown by numerical computations that the plastic flow in the compositions is associated with the calculated yield loci of reinforced media. As an example, yield loci for metal compositions with high-strength and low-strength binder and for fiberglass reinforced media are constructed. The calculated yield loci of the compositions are compared with the ones determined using different variants of the structural model with one-dimensional stress state in fibers.