De-coupled multi-scale analyses of fiber-reinforced composites by elastic-creep-damage combined model

The numerical study is made to illustrate the applicability of the method of decoupled multi-scale analysis to the micro-macro evaluation of the mechanical behavior of carbon-fiber-reinforced plastics (CFRP) that exhibit inelastic deformations and internal damage of the matrix material. During the course of this illus- tration, it is confirmed that the reliability of the decoupled method can be guaranteed if the macroscopic constitutive model is introduced so as to inherit the microscopic material behavior. To this end, with ref- erence to the results of the numerical material testing on the periodic microstructures (unit cells) of CFRP, we propose an anisotropic elasto-plastic-creep-damage combined constitutive model to represent the macro- scopic material behavior and demonstrate the characteristics of the inelastic deformations that resemble the material behavior assumed for plastics at micro-scale. With the identified macroscopic material parameters, the macroscopic structural analysis, which is followed by the localization analysis consistently, can be an actual proof of the utility value of the decoupled method in practice.