Practical Applicability and Limitation of Representative Volume Element Approach to Model Creep Behaviors of Metal Matrix Composites

摘要

The applicability and effectiveness of the representative volume element (RVE) approach for predictions of creep properties in metal matrix composite materials were analyzed numerically in this paper. A special attention was paid to the sensitivity of numerical solutions with respect to the volume element size, in terms of short-term creep strength and secondary creep rate of the model. The numerical models were based on the microstructure of composite material which consisted of creeping matrix with randomly distributed non-creeping hard spherical particles. A modified random sequential adsorption algorithm was applied to reproduce volume elements of composite microstructures. Then, the elements were subjected to creep deformations with uniaxial stress boundary condition. Statistical analysis of numerical experiments for different volume element sizes showed that the effective creep properties can be determined for large volumes of the elements. In both cases of creep strength and secondary creep rate, the statistical fluctuations of the numerical solutions were decreased with increasing volume of element. Several test cases are also presented in order to validate the model against experimental results from literature, and the advantage and limitation of the RVE approach are discussed.