Flexural failure mechanisms of three-dimensional woven textile sandwich panels: Experiments

Abstract

Three-point bending tests were conducted to reveal the failure mechanisms of the three-dimensional WTSC. Sixteen groups of experiments were designed and performed based on the orthotropic core structure and different thicknesses of the two skins. Bended along the weft direction, skin yielding and crimpling renders WTSC ductile failure mode. Bended along the warp direction, skin cracking renders WTSC brittle–ductile failure mode, while core shearing renders a quasi-brittle mode. After the initial failure, the progression of plastic hinges renders WTSC residual load capacity in a long deformation plateau, while fractures of lower skins lead to complete and abrupt failures. According to the experiments, failure mechanisms of WTSC include skin fracture, skin yielding, skin crimpling, tensile failure, indentation, and core shearing. Strength of the skins and the core in the warp and weft directions were predicted. The woven skin and the woven core are stronger in the weft direction. These failure mechanisms lead to six typical styles of flexural deflection curves having different brittle and ductile characteristics.