Compressive strength assessment of fibre composites based on a defect severity model

This paper presents a defect severity concept for characterising fibre misalignments commonly found in practical composites. Drawing an analogy with brittle fracture from sharp defects, we show that compressive failure is governed by regions with clusters of misaligned fibres and that failure occurs from a critical region most favourable to initiating a kink-band. Based on a large database of measured fibre misalignments, a defect severity model is proposed. The initiation and progression of kink-bands are also analysed using a finite element model