Experimental characterization of the compressive properties and failure mechanism of novel multiaxial 3D woven composites

This paper reports an innovative multiaxial 3D orthogonal-interlock woven architecture and weaving process, associated with the compressive properties of its composites. Three types of multiaxial 3D woven composite plates with different bias yarn contents (S1: 22.7%, S2: 27.1%, and S3: 33.2%) are prepared, compressive are loads applied in both the warp and weft directions, and the failure mechanism is evaluated using microcomputed tomography (micro-CT). The experimental results show that the compressive stress-strain curves of the specimens S1 and S2 under warp loading follow a linear increase prior to the peak stress, while that of the specimen S3 increases nonlinearly up to failure. Additionally, the stress-strain curves of all specimens loaded in the weft direction show a linear response within the full strain range. S1 and S3 withstand the maximum compressive strengths in the warp and weft directions accordingly. The compressive properties of multiaxial 3D woven composites mainly depend on the directional fiber content along the loading direction. CT image slices show that matrix cracks, fiber/matrix interface debonding and fiber breakage/splitting are the major failure patterns of multiaxial 3D woven composites subjected to compression loads.