Adhesively-bonded repairs to fibre-composite materials II: Finite element modelling

Part I described the static performance (i.e. the performance under a monotonic rate of loading) of carbon-fibre reinforced-plastic (CFRP) composites which had been repaired by adhesively bonding and co-curing, a second section of CFRP prepreg to the original parent material. The mechanical behaviour of these repair joints, as well as of the adhesive and CFRP forming the joint, were determined both in the unaged condition and after ageing. The hot/wet ageing of the repair joints and materials was simulated by immersing the joints and materials in water at 50 degrees C. In Part II, the mechanical properties of the adhesive and the CFRP have been used in conjunction with a finite element analysis (FEA) to determine failure criteria which would predict the experimentally observed failure paths and strength of the adhesively-bonded repair joints. Two material models were used for the adhesive: a linear elastic and linear elastic-plastic. Two models were also used for the composite. In the first model, the composite was assumed to be a homogeneous orthotropic material with smeared properties. In the second, it was modelled as a combination of individual plies of various orthotropic/anisotropic properties, depending upon the fibre orientation angle. Three possible types of failure for the repair joints were analysed in order to predict the expected failure paths and failure loads. The general agreement between the experimental observations, and predictions of the failure path and loads was found to be good. (C) 1998 Elsevier Science Ltd. All rights reserved.