A hybrid exact strip and finite element method for modelling damage in composite plates

• Main Author: Suliman, Basem Saoud
• Published: Cardiff University 2018
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.753585

Delamination is a frequent cause of failure in laminated structures, particularly under compressive loads. The presence of delaminations in composite laminates reduces their overall stiffness. In addition, delaminations tend to grow rapidly under postbuckling loads, causing further reductions in the structural strength and leading ultimately to a sudden structural failure. Recently, many studies have been carried out to investigate the effects of delaminations on the buckling and vibration behaviour of composite structures. Finite element analysis is often used to perform these due to its ability to model complex geometries, loading and boundary conditions, but this comes at a high computational cost. The exact strip method provides an efficient alternative approach using an exact dynamic stiffness matrix based on a continuous distribution of stiffness and mass over the structure, so avoiding the discretization to nodal points that is implicit in finite element analysis. However due to its prismatic requirements, the exact strip method can model damaged plates directly only if the damaged region extends along the whole length of the plate. This thesis introduces a novel combination of exact strip and finite element analysis which can be used to model more complex cases of damaged plates. Comparisons with pure finite element analysis and a previous technique based on the exact strip method demonstrate the capability and efficiency of this hybrid method for a range of isotropic and composite plates.