Strain Rate Dependent Behaviour of Self-Reinforced Polypropylene Composites and their Hybrids

Abstract Strain rate is one of the external parameters to affect the behaviour and response of polymer composites due to their viscoelastic properties. Therefore, understanding the strain rate effect on the materials’ properties is crucial. The current work demonstrates the strain-rate sensitivity of self-reinforced polypropylene composites (SRPP) and their interply hybrids with glass fibre in bending loading. Hybridisation of SRPP with the glass reinforcement changes the strain-rate dependence behaviour. It was concluded that increasing strain-rate resulted in increasing both the strength and the modulus of the structures but the modulus dependence on strain-rate was less pronounced. For self-reinforced hybrid composites, a yield point was observed in the stress-strain flexural curve where the low strain failure glass laminate fails. The failure strain of GRPP, as well as maximum flexural strength, showed an increase by increasing the strain-rate.