An efficient modelling technique for simulation of guided waves in delaminated composite and sandwich structures

Abstract

The paper presents a higher order laminate model with sub-lamination capability for simulating wave propagation within delaminated composite and sandwich beams. Each sub-laminate adopts cubic and quadratic through-thickness variation for axial and transverse displacement, respectively. This is achieved by taking displacements at external surfaces, which are beneficial for connecting sub-laminates, used to model multilayered structures by stacking them in the thickness direction without additional treatment. The model has the flexibility to achieve the desired level of accuracy and computational efficiency by using a suitable sub-lamination scheme. The delamination can be inserted conveniently between two sub-laminates stacked one over the other. The effect of contact within delamination regions is also incorporated in this model to capture higher harmonics induced by a clapping mechanism produced during delamination closing. The model is implemented within a framework of spectral finite elements in the time-domain. The accuracy and computational efficiency of the model are thoroughly checked by solving numerical examples of wave propagation within intact/delaminated composite/sandwich beams. Detailed finite element (FE) models used to produce results for validation show that the proposed model can save more than 90% of computing time and memory compared to detailed FE modelling to achieve similar level accuracy. The model is finally utilised to investigate the influence of delamination sizes and location on the wave response of sandwich beams.