Static and dynamic mechanical behavior of 3D integrated woven spacer composites with thickened face sheets

3D integrated woven spacer composites with thickened face sheets are fabricated successfully. Static compression and impact behavior are analyzed to evaluate the effect of thickened face sheets. The results show that thickened face sheet is an important influence parameter, warp compression and impact properties have been improved significantly than those of composite without thickened face sheets. Moreover, the damage and failure mechanism is significantly different. The main failure mode under flat compression is an abrupt rigid breakage of core fiber bundles. However, the thickened face sheets reduce the shear stress that transfer to core fibers. For warp compression, there is no face sheets fracture or dislocation, the local shear fracture occurs on the thickened face sheets. In regard to low-velocity impact, the strength of thickened face sheets dominates the failure, the damage is mainly manifested as the penetration of the top and bottom face sheets, matrix cracking, interface debonding, micro-buckling, as well as tearing and breakage of core fibers.