Design strategy for 3D layer-to-layer angle interlock woven composites

• Elastic behaviour of 3D woven composites can be systematically designed. • Key properties of the weave (KPoWs) represent the 3D woven geometry. • Effective elastic properties follow trends with respect to KPoWs. • Manufacturing parameters are related to effective elastic properties through KPoWs. • KPoWs-based design is a systematic alternative to conventional trial and error. A design strategy for 3D layer-to-layer angle interlock woven composites has been established by employing a set of three key properties of the weave (KPoWs): the global fibre volume fraction, the interlocking angle and the ratio of the weft tow volume to the warp tow volume. Using analytically derived expressions of the KPoWs, their variation trends relative to the manufacturing parameters have been revealed. At the same time, via a range of systematic computational material characterisation exercises, the KPoWs were shown to be sufficient for representing the woven reinforcement as far as the elastic behaviour predictions are concerned, because the effective elastic properties were found to follow consistent variation trends with the KPoWs. As a result, through use of KPoWs, manufacturing parameters have been associated with the effective elastic properties in a systematic manner. This offer means for obtaining a desirable elastic behaviour of 3D woven composites via variation of their internal architecture. The design method developed is the alternative to trial-and-error-based selection method conventionally adopted for this type of materials. As an example of application of the proposed method, a woven composite with balanced weft and warp properties has been designed.