一方向ハイブリッド繊維強化材の引張破壊過程のシミュレーション

Abstract

The failure process of fiber reinforced composites is a complicated accumulation process of damage due to random failure of fibers, matrix and interfaces, which leads to a catastrophic fracture. A Monte Carlo simulation is one of the most effective methods to analyze such a complicated probabilistic phenomenon as a failure process of composites, and several investigations have been carried out in the past. In most of the past investigations, a simple failure model has been applied in which only random fiber break and stress concentration in the nearest fiber to the broken fiber are taken into consideration. This formulation, however, leads to no more than a flat cleavage plane of a specimen, which does not apparently agree with an actual observed phenomenon.The present paper proposes a new failure model considering interfacial debonding between fibers and matrix as well as fiber breakage. A tensile failure process simulation was carried out for unidirectional carbon fiber (C)/glass fiber (G) hybrid composites with two different kinds of hybrid constitution (concentrated versus dispersed) based on the proposed failure model. The simulation was compared with the observed results of hybrid model experiments based on an acoustic emission (AE) method.The present simulation showed a complicated zigzag cleavage plane in the specimen and also the clear difference in failure process depending upon hybrid constitutions. Furthermore, the simulated results agreed well in tendency with the model experiments in regards to the characteristic shape of stress-strain diagrams and AE properties.