Compressive strength and stiffness of filament-wound cylinders

In filament-wound composites, the existence of fiber undulation introduces unique challenges in the calculation of compressive modulus and strength using traditional composite theories. In the current work, a previously developed three-dimensional continuum representation of undulated fibers was incorporated into a multi-scale homogenization process to simulate the effective longitudinal stress-strain behavior of filament-wound cylinders and compressive failure in the undulation regions. Calculated properties were compared to previously obtained experimental data for carbon fiber cylinders made with various matrix materials and winding parameters. The average difference between predicted and measured properties was 14% and the predicted failure modes were consistent with the experimental observations.