Structural analysis of variable‐stiffness composite tubes produced by filament winding under radial compression and holes influence

Abstract A structural analysis of variable‐stiffness polymer composite tubes, produced by variable‐angle filament winding process, and subjected to radial compression testing is presented. The work methodology involves the comparison between constant‐angle and variable‐angle composite tubes, including transverse holes and stress concentration effects. A numerical procedure, coupling a finite element structural analysis with an optimization algorithm routine, was developed and performed to generate comparative composite tube designs with maximized strain energy. Results showed that for variable‐angle tube design the initial radial stiffness, maximum force, and strain energy, were improved. For the investigated case, the variable‐angle tube design with holes notably presented an initial radial stiffness improvement, 45.4% higher than the constant‐angle tube without holes. Reached an almost full maximum force recovery, only 3% lower than a constant‐angle tube design solution without holes. In addition, it showed a strain energy c.a. 13% better than the constant‐angle design with holes solution. The observed results highlight special features promoted by the variable‐angle manufacturing strategy, which allow the exploitation of different structural behaviors according to specific requirements. Highlights Mechanical analysis of variable‐stiffness composite tube with holes under radial compression. Numerical procedure for composite tube design definition and analysis. Presents a variable‐angle composite tube manufactured by filament winding. Mechanical response comparison between constant‐stiffness and variable‐stiffness composite tubes. Enhancement of structural performance with the proposed composite tube design.