Damage failure analysis of flexible-oriented three-dimensional woven composites with void defects: An experimental and numerical study

Three-dimensional woven structures have garnered significant interest due to their enhanced mechanical properties and structural integrity. This study delves into a detailed analysis of progressive damage failure in multi-structured, flexible-oriented three-dimensional woven composites (FO3DWC), with a specific focus on the effects of voids. Employing the flexible-oriented three-dimensional woven process (FO3DWP), four distinct structures were fabricated and subjected to uniaxial tensile tests. The study integrates an progressive damage failure model coupled with a random element selection method to investigate the effects of void defects on mechanical properties. The results show that significant variations occur in the strength of the L45135 structure due to the void defects, with a maximum decrease of up to 4.37% when the porosity is 5%. This research provides a quantitative understanding of how voids impact the mechanical performance of FO3DWC, offering valuable guidance for material design and application in various engineering fields.