Analysis of interfacial fracture toughness for laminated composites repaired with adhesive

In this study, adhesion interfacial fracture toughness in layered composite plates was searched for different fiber orientation angles and symmetric layer array as experimentially and numerically. In the research, composite plates are four layers and the layer arrays are [0º/θº/θº/0º]. In the study that was applied double cantilever beam (DCB) test, composite boards which were reinforced with epoxy resin matrix and unidirectional carbon fiber were used θº was identified as fiber orientation angle. As a result, effects of fiber orientation angle changes on fracture toughness was investigated. For each fiber angle and layer arrays, numerical fracture toughness was calculated by using critical load-place changing values which are gotten experimentially and start crack spreading. For DCB test, ANSYS, which is experimental sample model, was done by using finite element method. At the numerical study, composite materials which are four layers were prepared as three-dimensioned. Below critical place values, Mod I fracture toughness in the crack tip was calculated by using VCC (Virtual Crack Closure) technique. The Numerical values which are in line with the experimental results were presented as graphics.