An evaluation of the loading direction sensitivity of 3D woven composite with novel web-shaped Z-binder architecture

Abstract 3D orthogonal (ORT) through-thickness woven composites have excellent out-of-plane properties but exhibit inferior in-plane properties and are loading sensitive. This study proposes a novel web-shaped orientation of z-binder architecture in 3D orthogonal through-thickness model with in-plane uniform elastic moduli to address this drawback. On-axis tensile, Off-axis tensile and In-plane Shear tests were performed on the four macroscale models (ORT_on, WEB_on, ORT_off, WEB_off). The ORT model, validated by data from the literature, was used as a reference for the proposed WEB model. The overall fibre volume fraction of the WEB_on, and WEB_off models were 7.07% and 8.67% lower than the ORT_on, and ORT_off models. In the on-axis tensile test, the E_x and E_y were lower by 16.89% and 2.66% for WEB_on model, but in the off-axis tensile test, they were higher by 13.75% and 13.77% for WEB_off models. The G_xy was 10.96% lower for WEB_on model. The difference between the E_x and E_y under on-axis loading conditions was 14.81% for ORT model, whereas 0.22% for WEB model. Thus, the proposed WEB shaped z-binder architecture model outperforms the ORT model under the off-axis and is comparable in transverse loading conditions. It also possesses loading direction insensitivity, unlike the ORT model.