ADHESIVELY-BONDED REPAIRS TO FIBER-COMPOSITE MATERIALS II - FINITE-ELEMENT MODELING

Part I described the static performance (i.e. the performance under a monotonic rate of loading) of carbon-fibre reinforced-plastic (CFRP) c omposites 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 adhesi ve and CFRP forming the joint, were determined both in the unaged cond ition and after ageing. The hot/wet ageing of the repair joints and ma terials was simulated by immersing the joints and materials in water a t 50 degrees C. In Part II, the mechanical properties of the adhesive and the CFRP have been used in conjunction with a finite element analy sis (FEA) to determine failure criteria which would predict the experi mentally observed failure paths and strength of the adhesively-bonded repair joints. Two material models were used for the adhesive: a linea r elastic and linear elastic-plastic. Two models were also used for th e composite. In the first model, the composite was assumed to be a hom ogeneous orthotropic material with smeared properties. In the second, it was modelled as a combination of individual plies of various orthot ropic/anisotropic properties, depending upon the fibre orientation ang le. Three possible types of failure for the repair joints were analyse d in order to predict the expected failure paths and failure loads. Th e general agreement between the experimental observations, and predict ions of the failure path and loads was found to be good. (C) 1998 Else vier Science Ltd. All rights reserved.