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

Abstract

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 [+θ₂, 90₂, -θ₂, 0₂]_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.

Keywords

• E-glass/epoxy,Double Cantilever Beam,Delamination,Mode I Fracture

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