Microscopic Strain of Random Discontinuous Fiber Composites Subject to Various Macroscopic Strain Conditions

Abstract

With the wide applications of composite materials, virtual simulation tools become a big matter of concern in the new development process to predict the behaviors of materials before fabricating. The mechanical properties, behaviors of composites are strongly dependent on their microstructures. To link the gap between microstructure to macroscopic properties, the homogenization technique is used. Conversely, the localization technique is utilized to investigate the behavior of constituent materials at microstructure under macroscopic loading conditions. In this paper, the asymptotic homogenization (AH) method is applied to investigate the behavior of fibrous composite materials under different macroscopic strain conditions which are very complicated to carry out by experiment works. For demonstration, a short fiber reinforced plastic model with random fiber orientation, random fiber arrangement, and random fiber length is analyzed. The influences of strain conditions on this complex microstructure on the microscopic strain distribution are observed and visualized on any arbitrary cross-section. The results show that the high microscopic strain arises more in the case of coupled shear strain conditions through histograms, whereas the largest microscopic strain appears in the case of coupled transverse strain and shear strain conditions. This analysis is worthy of the discontinuous fiber composite material design, initial damage prediction, and damage propagation analysis for further steps.