Towards virtual material characterisation of unidirectional composites with microscopic simulations

Abstract

This paper reports on the experimental and numerical investigation of IM7/8552 unidirectional composites. Polished composite samples have been investigated using an optical microscope and an automatized algorithm for pattern recognition to determine the distribution of radius and inter-fibre distance. Based on the obtained parameters, multiple unit cells have been generated and virtually loaded in tension, compression and shear to generate material properties while taking into account stochastic effects. To reduce computing time, several parameters such as unit cell size, mesh fineness or boundary conditions have been investigated beforehand. In a second time, material models available in LS-DYNA have been compared with focus on computational effectivity and result accuracy. Moreover, effect of loading rate on unidirectional properties has been investigated. Compared to experimentally-measured mechanical parameters, first numerical results show a promising path towards a predictive tool for unidirectional composites.