Predicting the compressive engineering performance of carbon fibre-reinforced plastics

This paper examines the compressive strength data of a recent experimental study [Smith FC. The effect of constituents' properties on the mechanical p erformance of fibre-reinforced plastics. PhD thesis. Centre for Composite M aterials, 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 kinki ng analysis [Budiansky B. Micromechanics. Comput Struct 1983;16(1):3-12] an d a linear softening cohesive zone model (CZM) [Soutis C, Compressive failu re of notched carbon fibre-epoxy panels. PhD thesis. Cambridge University E ngineering Department, UK, 1989; Soutis C, Fleck NA, Smith PA. Failure pred iction technique for compression loaded carbon fibre-epoxy laminates with a n open hole. J Comp Mat 1991;25(5):1476-1498] are used for the prediction o f 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 m odelled as an equivalent open hole and the cohesive zone model [Soutis C, C ompressive failure of notched carbon fibre-epoxy panels. PhD thesis. Cambri dge 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 t o estimate compression-after-impact (CAI) strength. The unnotched strength is accurately predicted from the knowledge of initial fibre misalignment an d 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%. (C) 2000 Elsevier Science Ltd. All rights reserved.