Multi-scale analysis of effects of constituent properties on open-hole tension performance of composite laminates

The effect of constituent properties on open-hole tension performance of CFRP was studied by means of a combination of experiments and numerical simulations. A new stress-based multi-scale failure model was proposed, in which failure criteria of constituents were carefully determined based on experimental results. Open-hole tension performance of three material systems (T300/5228, T300/5428, T700/5428) were examined. Good agreements were found between the experimental results and the numerical simulations. It was found that fiber strength was a key factor influencing ultimate strength of the laminates, while matrix property degradation alleviated the stress concentration. The relative strength of fiber and matrix determined the OHT strength and failure mode, as well as types and extent of internal damage in the notched composites prior to failure.