Experimentally based strategy for damage analysis of textile-reinforced composites under static loading

For a reliable design of components made of textile composites, a deep knowledge of their failure behaviour and of realistic damage models is necessary. Such models require the onset of damage and the evolution of different damage phenomena to be determined experimentally. In this context, an experimental damage analysis strategy is proposed here that combines crack density measurements, acoustic emission analysis and optical microscopy with the recording of stiffness degradation by ultrasonic wave speed measurements. The correlation between the results of quasi-static tests is discussed for two selected examples of textile composites: multi-layered flat bed weft-knitted glass fibre–epoxy composites and woven glass fibre–polypropylene composites made of hybrid fabrics.