Effect of Fiber Distribution on Elastic-Viscoplastic Behavior of Long Fiber-Reinforced Laminates
Tetsuya MATSUDA, Nobutada OHNO, Hiroki TANAKA and Toshihiro SHIMIZU
Abstract:In this work, the effect of transverse fiber distribution on the elastic-viscoplastic behavior of long fiber-reinforced laminates is studied using a homogenization theory. To this end, a basic cell with random fiber distribution is arranged point-symmetrically with respect to the cell boundary facet centers. The basic cell is also arranged Y-periodically. It is demonstrated that the point-symmetric arrangement enhances the randomness of fiber distribution than the Y-periodic arrangement. Then, by assuming the point-symmetry based fiber distribution as the transverse fiber array in laminae, the in-plane elastic-viscoplastic deformation of CFRP laminates is analyzed using the homogenization theory of nonlinear time-dependent composites. Comparative analysis is further performed by assuming the perfectly periodic, hexagonal fiber distribution in laminae. It is thus shown that the transverse randomness of fiber distribution has negligible influence on the macroscopic elastic-viscoplastic behavior of laminates, whereas the microscopic distribution of stress in laminae is markedly affected by the fiber distribution. It is also shown that the results of analysis agree very well with the corresponding experimental results. Key Words:Homogenization, Fiber distribution, Point-symmetry, Laminates, CFRP, Viscoplasticity