Compressive failure behaviour of composite laminates due to the effects of cutout sizes and variation in fibre orientations

Abstract

Composite laminates have become progressively trending due to its tailorable of material properties, thus widely used in modern structures. Nevertheless, due to the complex fiber-matrix interaction added by the existing of cutouts, it is complicated to understand the failure mechanism and deformation behaviour of composite laminates. Based on literature review, the studies on the effect of various diamond cutout sizes and fibre orientations to the composite laminates are limited but in reality, the application of diamond cutouts are found practical for many composite structures. This paper aims to study the effect of various diamond cutout size to the failure behaviour of T300/5208 Graphite/Epoxy and UD Kevlar/Epoxy with various fibre orientations under uniaxial compression. Failure analysis was conducted using the Finite Element Simulation (ANSYS) based on Maximum Stress Theory. The results show a noticeable strength difference between composite plates with and without cutout. The main finding deduced from the study is that the existing of diamond cutout shape reduces the compressive strength of Graphite/Epoxy and Kevlar/Epoxy composite laminates up to 100 and 10 times respectively. The fibre orientation has greater effect in reducing the compressive strength of the composite laminates compared to the cutout size. This information is important in designing practical composite structure where cutouts exist, and thus this study has significantly contributed new fundamental knowledge.