NUMERICAL INVESTIGATION OF FLEXURAL PERFORMANCE OF REPAIRED GFRP COMPOSITE SANDWICH BEAM WITH HYPER-ELASTIC MATERIAL AS CORE

In a sandwich structure, laminated composite face sheets may have non-acceptable manufacturing flaws or in-service damages, which needs to be repaired to avoid rejection of full part. Different combination of face sheets and cores are being explored to maximize their potential by many researchers. This study presents a numerical investigation of flexural performance of localized repaired face sheet of a sandwich beam, which consists of glass fiber-reinforced plastic (GFRP) composite face sheets and hyper-elastic material core. Three models representing pristine, damaged and repaired configurations were constructed using finite element method. Cohesive zone modeling approach was used to simulate the damaged and repaired configurations. Damage and its repair were modelled at different thickness locations. Three-point bending simulations have been carried out with consistent geometry, boundary conditions and material definitions for all configurations. Layer-by-layer stress fields were extracted and compared to evaluate the residual strength in damaged configurations and strength restoration in repaired configurations without weight penalty. The approach of this study will help in evaluating the performance of repaired sandwich structure with hyper-elastic core material.