Automatic ply detection and finite element model generation for composite laminates

Abstract

This paper presents a novel methodology to detect and isolate individual ply information contained within a relatively low-resolution cross-section image of thick composite laminate specimens. The proposed method can process laminate sample images and construct detailed geometric models in a fast and automated manner with minimal user interaction. The finite element models can be used directly for structural and strength simulations to analyse the effect of waviness defects. The algorithm processes the greyscale sample image and splits it into multiple slices. The initial starting points for each ply were identified by analysing the pixel brightness of the image. The pixel brightness variation was used to identify the different plies in all image slices and a list of possible ply centreline coordinate is generated. The ply centreline points are grouped and connected by selecting the points with minimal distance to the previous one in the ply. A finite element mesh is created for each ply by creating a boundary at the midpoint between two adjacent plies. The geometric information of the isolated plies is then used to create structured finite element models using an in-house meshing algorithm.