Beam and finite element analysis of quasi-unidirectional composite SLB and ELS specimens

The mixed-mode I/II delamination problem in composite specimens was investigated using closed-from solutions, the finite element technique and experiments. Unidirectional glass/polyester composite laminates were manufactured and tested. The mixed-mode I/II SLB and ELS specimen configurations were used in order to obtain compliance and fracture energy predictions. Linear beam theories incorporating transverse shear and elastic foundation effects were utilized to calculate the displacements of both the SLB and ELS specimens. The compliance and fracture energy was calculated as the superposition of the various contributions. Plane stress finite element models including some accompanying effects were constructed. The analytical and numerical results were compared with the experiments and very good agreement was found.