A robust and automated method for geometric modelling of thick laminates with multiple and asymmetric ply wrinkles

Ply wrinkles are often found in thick laminates and they are known to be a major failure cause of composite structures. To assess the criticality of the ply wrinkles accurately and efficiently, the complex wrinkle geometries -which are commonly simplified as a single sinusoidal, Gaussian or combined function, should be described precisely and preferably in an automated manner. This study presents a robust method for automated geometric reconstruction and finite element meshing of entire thick laminates with multiple, asymmetric out-of-plane ply wrinkles. We extract coordinate information of each data point along the plies from inspection images, subsequently, multiple Gaussian functions are used to best fit the complex wrinkle geometry. To reconstruct the entire laminate, we interpolate ply geometries of the intermediate layers based on the fitted layers. Finite element models of thick laminates with the concerned ply wrinkles are subsequently generated and analysed to assess structural criticality. The entire procedure is automatised and is implemented in MATLAB codes. The demonstration studies show the robustness and efficiency of the proposed method which can contribute to closing the gap between non-destructive testing and criticality assessment of thick laminates with ply wrinkles.