Constant wall thickness winding of filament-wound revolution shell and elbow structures

Abstract

Constant wall thickness winding is a widely used processing technique in filament winding industry. The current methods almost used geodesic or semi-geodesic winding on revolution shell and elbow, which maybe result in non-uniform thickness distribution. The aim of this work is to reveal the mandrel and winding angle requirements of constant wall thickness wound conical tube and elbow, and the effect of winding angle on their mechanical performances. Firstly, constant wall thickness winding trajectory and the formula for finding its slippage coefficient are given on the revolution shell and elbow. Secondly, a design method for constant wall thickness winding on the conical tube and elbow is proposed based on the approaches to determine winding trajectory stability. The winding pattern designed by this method can ensure that the fibers fully cover the mandrel, and there is the same wall thickness at any region except for the end turnaround regions. Finally, a finite element analysis model is established to investigate mechanical performances of constant wall thickness wound structures. The results demonstrate that mechanical performances of constant wall thickness wound conical tube are improved with the increasing initial winding angle, and the elbow structure achieves best mechanical performance when the initial winding angle is about 49°. The ratios of their maximum burst strength to minimum burst strength are at least 3 and 1.4, respectively. Based on these principles and methods, a CAD tool is developed to design constant wall thickness winding.