Novel concepts optimization for functionally graded adhesives used in bonded composite patch repairs techniques
M. W. Harmel, K. Zouggar, K. Madani, M. Benyettou, R.D.S.G. Campilho, Meisam Jalalvand
Abstract
This study consists of a Finite Element (FE) analysis on the use of a graded adhesive material to repair a damaged plate. The numerical model was developed using a combination of two eXtended Finite Element Method (XFEM) techniques to automatically propagate the crack in the damaged plate and the cohesive zone model (CZM) technique for adhesive debonding. The mechanical and cohesive properties of the two adhesives were introduced according to the volume gradation exponent using the USDFLD subroutine in the Abaqus® computer code. Several gradation designs between the two adhesives were considered to determine their performance in transferring load from the damaged zone to the patch. The results of the tensile curve analysis and the adhesive layer debonding analysis showed that the use of functionally graded adhesives (FGA) can improve the performance of the repair process by delaying debonding, depending on the choice of adhesive and the proposed design.