Numerical analysis of the DCB test configuration applicability to mechanically coupled Fiber Reinforced Laminated Composite beams

This article presents a numerical FE study on the mode I strain energy release rate (SERR, GI) distribution along delamination front in mechanically coupled laminated composites deformed in accordance with the DCB test configuration as described in the ASTM D 5528 Standard. The standardized boundary conditions were compared to the freed ones and two kinds of the laminate stacking sequence were considered. The bending-twisting coupling having the superior meaning in the case of mode I experimental tests was simulated in the Abaqus/CAE finite element software environment with its VCCT facility. The beam models were examined towards the crack front shape and the mode I SERR distribution. The results were compared to those obtained for other coupled, as well as uncoupled layups. Two dimensionless parameters describing GI distribution were introduced and related to the other results. The advantages of the standardized DCB test setup and possible problems with the results validity in case of the coupled laminates were examined. A usefulness of the results in the allied buckling tests of composite profiles made of coupled laminates from the point of view of delamination resistance was discussed.