EXPERIMENTAL AND NUMERICAL INVESTIGATION OF EFFECTS OF CURE CYCLE ON PROCESS-INDUCED-DISTORTIONS OF CARBON FIBRE REINFORCED COMPOSITES

摘要

Processing of composite materials involves complex phenomena such as heat transfer, resin flow, resin cure and stress development. Evolution of the material behaviour during cure process, results in development of residual stresses. Consequently, the cured product has different dimensions at room temperature from the tool it was processed on.Process simulation of composites offers effective means for understanding the effects of process parameters and variables on the finished product and reducing manufacturing risks and costs. The accuracy and efficiency of process simulation is highly dependent on models that capture the behaviour of the composite material as it evolves during cure process.In this paper we have experimentally and numerically investigated the effect of complex cure cycles on process-induced distortions of parts made of CYCOM? IM7/5320-1 CFRP system. These cure cycles include isothermal holds at different temperatures and also off-the-tool post curing. Manufactured parts were scanned using a coordinate measurement machine. The process is also simulated using the process modelling platform COMPRO-CCA. Simulations included representation of various aspects of the curing material including its cure kinetics, resin modulus development (CHILE, Viscoelastic and Elastic-Viscoplastic constitutive models), thermal expansion and cure shrinkage. Model predictions are validated against the experimental measurements.