Evaluation of Mechanical Properties of Composite Laminates by Fractal Dimension

Abstract

This study focuses on the evaluation of mechanical properties of composite laminates by fractal dimension (FD). The fibre distribution in a laminate or FD could be changed according to different manufacturing processes, such as hand lay-up, resin infusion and resin transfer moulding. These manufacturing processes are considered in this study. Woven Kevlar / epoxy composite panels were manufactured with a [0/90]2S stacking sequence. The materials were characterised for interlaminar shear strength (ILSS) and flexural strength. The fibre volume fraction (Vf) and FD of the laminates were determined from optical microscopic images of polished cross-sections using ImageJ software (box counting method) with the Fractal and Lacunarity add-in. The results show significant relationships between the mechanical performance of the composite laminates and the FD.