Mechanical properties of hand-making polyester composites

Abstract

The aim of this paper is to determine the effect of arrangement of fibreglass fabric plies in a polymer composite on a strength. Based on the experimental results, the real effect of plies arrangement and their most favourable configuration with respect to strength is determined. The experiments were performed on 4 types of handmade composites which had different fibre orientations and thicknesses. The first three of the composites had three plies of fabric. The plies arrangement in Composite I was unchanged, in Composite II the central ply had the 45 degrees orientation, while in Composite III the outside ply (tangential to the adhesive layer) was oriented at 45 degrees. In contrast. Composite IV consisted of five plies with unchanged arrangement. Composite plates were first cut into smaller specimens and then after stabilizing, the composite specimens were subjected to strength tests. The highest tensile strength and elongation are obtained for Composite IV, which was the higher the thickness from the tested composite samples, but for this composite the tensile modulus was lowest value. Composite II has the lowest values of strength parameters among the tested composites, which contain three plies and central ply has the 45 degrees orientation.