Predicting the compressive engineering performance of carbon fibre-reinforced plastics

Abstract

Abstract This paper examines the compressive strength data of a recent experimental study [Smith FC. The effect of constituents’ properties on the mechanical performance of fibre-reinforced plastics. PhD thesis. Centre for Composite Materials, Imperial College, April 1998] concerned with the evaluation of a range of engineering properties of continuous carbon fibre/epoxy composites subjected to static tensile and compressive loading. A plastic fibre kinking analysis [Budiansky B. Micromechanics. Comput Struct 1983;16(1):3–12] and a linear softening cohesive zone model (CZM) [Soutis C. Compressive failure of notched carbon fibre–epoxy panels. PhD thesis. Cambridge University Engineering Department, UK, 1989; Soutis C, Fleck NA, Smith PA. Failure prediction technique for compression loaded carbon fibre–epoxy laminates with an open hole. J Comp Mat 1991;25(5):1476–1498] are used for the prediction of the unnotched and open hole compressive strength (OHC) of unidirectional and multidirectional laminates made of six different commercially available CFRP prepregs. Damage introduced by drop-weight (low-velocity) impact is modelled as an equivalent open hole and the cohesive zone model [Soutis C. Compressive failure of notched carbon fibre–epoxy panels. PhD thesis. Cambridge University Engineering Department, UK, 1989; Soutis C, Fleck NA, Smith PA. Failure prediction technique for compression loaded carbon fibre–epoxy laminates with an open hole. J Comp Mat 1991;25(5):1476–1498] is applied to estimate compression-after-impact (CAI) strength. The unnotched strength is accurately predicted from the knowledge of initial fibre misalignment and the shear yield stress of the composite, while the difference between the theoretical and experimental OHC and CAI strength results in most cases is less than 10%.