STUDY OF THE EFFECT OF IN-PLANE BRAID DISTORTIONS ON THE MECHANICAL PROPERTIES OF BRAIDED COMPOSITES USING STOCHASTIC TOOLS AND FINITE ELEMENT MODELLING

摘要

In this paper, three types of braided composites each with different in-plane distortions, with a mean braid angle of 45° braid angle have been produced, to the study the effect of in-plane distortions on the tensile behaviour (in axial direction) of braid composites. The first type of braid composite contained distortions introduced during preform manufacturing, handing and lay-up process; the second and third of composites had these distortion but in addition each also contained tailored distortions. The in-plane distortions of these three types of braid composite in terms of changes in braid angle, and braid axis deviation has been studied using stochastic tools. In addition the axial tensile behaviour of three types of composite produced is compared with a perfect braid, produced with help of finite element (FE) software (Abaqus CAE), using a unit cell shell based model. This paper also develops an algorithm to automatically determine the braid angle which is an optimised version.