Evaluation of multi-directional compression behaviors and failure of three-dimensional orthogonal woven composites via liquid nitrogen temperature

Three-dimensional orthogonal woven composites (3DOWCs) are extensively employed in structural engineering applications for their lightweight, high designability, and excellent interlayer performances. This work constructed two 3DOWCs with different fiber volume contents, and their multi-directional compression properties and damage mechanisms at room and liquid nitrogen temperatures (RT and LNT) were thoroughly investigated and evaluated. Temperatures, fiber volume contents, and loading directions all had a significant influence on behaviors. The stress-strain curves presented ductility at RT and gradually decreased after reaching the maximum load, whereas they were brittle and rapidly decreased at LNT. Compared to the compression properties at RT, the compression strength of 3DOWC40-LNT and 3DOWC50-LNT increased by 22.6% and 9.3% in the warp direction, 11.8% and 29.0% in the weft direction, as well as 32.9% and 24.6% in the Z direction. Additionally, edge yarn stripping and shear cracking were the primary fracture patterns for 3DOWCs under RT, while they exhibited interface layering, yarn fracture, shear cracking, and interfacial debonding at LNT, especially the deformation along the warp direction was more pronounced under Z direction compression.