Micromechanical modelling on cyclic plastic behaviour of unidirectional fiber reinforced aluminium matrix composites

This work investigates the cyclic plastic behavior of continuous fiber-reinforced aluminum matrix composites (CFAMCs) with different volume fractions of fiber up to a maximum value of 63.61% using micromechanical approach of modeling. Shakedown, ratcheting limit and load-bearing capacity have been studied. The FEM models, based on two dimensional micromechanical representative volume element (RVE) with a square packing geometry, were subjected to constant macro stress under off-axis loading condition and thermal cycling conditions. A number of direct numerical methods, under the Linear Matching Method (LMM) framework, are adopted for the determination of limit load, reverse plasticity limit and ratchet limit of AMCs. The typical micromechanical model adopted in all analysis consists of continuous fibers with circular cross section, embedded in an aluminum matrix. Two most common reinforcing materials alumina and silicon carbide are investigated. Various factors that affect shakedown and ratcheting behaviors of composites are analyzed and discussed, including effects of fiber volume fraction and temperature on the AMC’s low cycle fatigue life.