WEB Contribution to Structural Mechanics of Patch-Based CompositesRoom 2
Fiber Patch Placement (FPP) is a novel, fully automated and resource-efficient manufacturing technology for complex shaped composite structures. A patch-based laminate layup offers curvilinear fiber orientations along load paths and high design freedom with least waste and fiber distortion. Initial research on this new type of composites has shown that, due to the patch-based fiber architecture, the structural mechanics of FPP laminates is fundamentally different in comparison to classic laminates. While in classic laminates the load transmission is performed mainly via normal stresses in the continuous fibers, in patch-based composites there is a shear-dominated transmission of forces between the patches. In this paper that structural mechanical difference is investigated with regard to strength properties for two different patch-overlap approaches. Composites manufactured by the fiber patch placement technology also require a new description in terms of failure mechanics. Each butt-joint between two patch ends forms a structural weak spot. Therefore, the failure characteristic of FPP structures will be determined by an alternation between joint failure and overlap failure. That kind of damage development will be sectional modeled based on the analytical concept of linear-elastic fracture mechanics.