On the Calculation of Energy Release Rates in Composite Laminates by Finite Element, Boundary Element, and Analytical Methods

Abstract

To characterise a transversal crack evolution in a cross-ply [0/90] s fibre reinforced composite laminate, the associated energy release rate (ERR) was calculated by means of the J-integral embedded into the Finite Element Method (FEM). The ERR values computed for the propagation of the transversal crack were correlated to the ones obtained by using the Virtual Crack Closure Technique (VCCT) embedded within the Boundary Element Method (BEM). In addition, the results were compared with analytical values. The results correlated well except when the crack length was approximately 80% of the ply thickness. In such case, ERR values showed some discrepancies between FEM and BEM. The reason stems from the fact that in the VCCT used not all components of the stresses are considered, resulting in smaller ERR values. In addition, the results proved that transversal cracks can influence each other only in a limited distance.

The Fracture Behavior of Pure and Hybrid Intraply Knitted Fabric-Reinforced Polymer Composites

“…The J-integral approach is a measure of the energy release rate associated with crack onset. One of the advantages of using J-integral is that under quasi-static conditions, it is equal to the energy release rate G for linear elastic materials [39]. Assuming linear elastic conditions prevailing along the integration path Γ, the numerical value of the J-integral can be related to the fracture toughness in plane stress condition as in Eq.…”

An enhanced void-crack-based Rousselier damage model for ductile fracture with the XFEM

“…However, for the first time, in this paper, XFEM is combined with the Rousselier model, thus enabling the crack to propagate while keeping the observation of the void volume fraction. Hence, the energy concentration exerted by the crack is released when the crack propagated (Curiel-Sosa et al, 2018;Tafazzolimoghaddam and Curiel-Sosa, 2015) and resulted in a much lower void volume fraction compared to the case without crack extension. Nevertheless, the results are still can be acceptable in a purpose to predict the void damage formation with crack development.…”