Failure factor of reinforced layer for fiber-wound composite pipe under different loads

This study examined the failure mechanism of fiber-wound composite pipe and determined the optimum winding angle. Simulation models of glass fiber-wound composite pipe were established. Failure factor of the reinforced layer of fiber-wound composite pipes under internal pressure, torsion, axial tension and bending load are investigated in conjunction with the three-dimensional Tsai-Wu failure criterion. The results show that the winding angle has a significant effect on the stress distribution of the reinforced layer. The inner layer of the reinforced layer is prone to failure under internal pressure. The outer layer of reinforcement layer under torsion is the easy failure position. The failure-prone layer under tensile load is related to the winding angle. The inner layer of the reinforced layer is prone to failure when the winding angle is less than 60°, and the outer layer is prone to failure when the winding angle is more than 60°. The outer reinforced layer is prone to failure under bending loads. When the winding angle is less than 50°, the easily failed failure position is on the inside of bending. When the winding angle is greater than 50°, the easily failed position is on the outside of bending. The smaller winding angle is conducive to improve the tensile, bending and torsion resistance of the composite pipe. The larger winding angle is beneficial for improving resistance to internal pressure. The optimal winding angle range for each load is different and multiple winding angles should be used in the design to obtain a higher overall load carrying capacity. The research results can provide a theoretical basis for the improved design, manufacture and evaluation of fiber-wound composite pipes.