Studying the nonlinear properties and strain-rate sensitivity of SiC short fiber-reinforced Al matrix composites

摘要

Stress-strain analysis has been an interesting issue for the mechanical design of composite structures. In this paper, a three-dimensional mechanical model based on generalized method of cells is presented to study the thermal residual stress and loading rates influence on the mechanical responses of short fiber-reinforced (SFR) composites. The effects of the fiber shape on the elastic constant of the SFR were investigated. To verify the prediction method, the calculated elastic modulus was compared with the results of finite element method. On this basis, a unified constitutive model is used to acquire the nonlinear properties of matrix materials. For comparison, SFR composites with and without consideration of thermal residual stress influences on the nonlinear responses are both considered. The results show that the distinct difference for SFR composites can be found at an early stage of loading. Meanwhile, the thermal residual stress influences on the mechanical behaviors present two characteristic stages.