Three-dimensional scaled boundary finite element method to study interfacial imperfections in thick laminated composite plates undergoing bi-axial bending

In this work, the scaled boundary finite element method (SBFEM) is employed to model weakly bonded thick laminated composite plates subjected to bi-axial bending. A three-dimensional modelling technique incorporated in the SBFEM framework is used for thick laminated plates, where two-dimensional plate models cease to provide accurate results. Weakly bonded interfaces are modelled using spring layer models with the incorporation of zero-thickness interface elements between the layers. The interface element is subjected to behave in a linearly elastic manner capturing the slippage between the layers. Using SBFEM, it is possible to have fewer discretisation in the through thickness direction of the plate (or individual lamina) without compromising the accuracy of the results. Additionally, the size of interface elements can be kept small without altering the size of the adjoining bulk element. Validation examples covering symmetric, anti-symmetric cross ply and angle ply laminates have been solved using the proposed approach. Results from the proposed method using SBFEM are compared with well-established methods for modelling thick laminated composite under bi-axial bending.