Characterization of Delamination Crack in Multidirectional E-glass/epoxy Composite under Mode I Loading

In this study, mode I critical strain energy release rate ( G Ic ) of unidirectional E-glass/epoxy was determined by double cantilever beam (DCB) test. Calculated G Ic was used to initiate delamination in numerical models. The effect of stacking sequence and fiber orientation of the sublaminates and the effect of thickness on mode I delamination crack length and G Ic distribution along the specimen width in 0 o //0 o interface have been studied using ANSYS ® . 3-D 8-node linear interface element INTER 205 is used to create a predefined crack path. To investigate the fiber orientation effect , composites with [+θ 2 , 90 2 , -θ 2 , 0 2 ] s stacking sequences were modeled. Interlaminar fracture analyses were performed by Virtual Crack Closure Technique (VCCT). Experimental and numerical critical loads ( P cr ) showed a good agreement. According to the results, while fiber orientation affects significantly the extended crack length and the G Ic distribution along the specimen width, stacking sequence only affects the G Ic distribution.