Proposal of Numerical Experiment for Discrete Fracture of Fiber Reinforced Composites

点击翻译按钮获取中文摘要

In order to evaluate the strength and toughness of composite materials, the following studies were carried out.1.Tensile tests of unidirectionally-carbon-fiber-reinforced plastic using smooth specimens, and the observation of fracture process.2.Stress analysis at the crack tip of Double Cantilever Beam specimen by means of Finite Element Method.3.Atomic and probabilistic analyzes on microcroaking.4.Numerical simulation of discrete fracture due to multiple microcracks.In the first study, transverse tensile tests of unidirectionally-carbon-fiber-reinforced plastic were carried out using smooth specimens, and the multiple small cracks initiated at the interface of carbon fiber and matrix were observed by means of microscope. The fracture process was discussed based on the observation results.In the second study, finite element analysis of the stress at the crack tip of Double Cantilever Beam specimen of unidirectionally-carbon-fiber-reinforced plastic was carried out. The effect of fibers on the stress distribution was examined and the applicability of conventional fracture mechanics to the composite material was discussed.In the third study, atomic and probabilistic analyzes on the microcrack were carrid out. The definition of microcrack was clarified and a method for determination of the distribution of internal microcracks from their cross-sectional distribution was proposed.In the last study, numerical simulation of the initiation and propagation of microcracks was carried out. The discrete fracture by microcracking was successfully simulated.