Abstract:

More uniform strength for all layers can be achieved by variation of winding angle to improve the utilization efficiency of filament-wound (FW) pipe. An optimization model of FW pipe under uniform internal pressure and axial force is built based to Tsai-Wu failure criterion to maximize the lowest strength ratio along thickness direction. An improved optimization algorithm derived from two conventional methods (complex method and steepest descent method) is proposed by optimizing the  winding angle of the layer by layer, and the minimum strength ratio is maximized. In three cases of pure hoop stress and the ratios of hoop stress to axial stress of 2:1 and 1:1, an optimization model of pipes made of E-glass/epoxy is illustrated to evaluate the improvement of the minimum strength ratio and the uniformity of the optimized winding angle distributionunder different ratio of thickness to radius, respectively. The research shows that the material utilization can be increased by proper winding angle variation. A quite uniform distribution of strength ratio along thickness can be realized easily by the optimization of the winding angle.

Key words: filament wound pipe, winding angle, failure criterion, fiber stresses