Geometric scaling of reinforcement and its pivotal role in design of 3D woven composites

Geometric scaling has been defined as means of producing equivalent 3D layer-to-layer angle interlock woven composite configurations that have different reinforcement geometries but identical, or very similar, effective elastic properties. Scaling rules have been derived under condition that the key geometric properties of the weave: the interlocking angle, global fibre volume fraction and weft to warp tow volume ratio, should not be affected by scaling. The role of tow sizes as designable parameters directly associated with scaling has been established for the first time. With scaling method in place, design of 3D woven composites can be defined as a two-stage process, where the effective elastic properties are varied via systematic variation of tow densities, while scaling is applied at a post-processing stage to ensure the practicality of design. The design process is comprehensive in a sense that it involves all the designable parameters, explicitly defining their roles and contribution. • Geometric scaling is a novel method of varying 3D woven composite architectures • Scaling rules are derived mathematically and are easy to use • Scaled composite configurations have identical, or similar effective elastic properties • Scaling can be viewed as means of ‘post-processing’ the design to make it practical