Effects of stitching parameters on the mechanical properties of stitched sandwich panel structures

This paper studied the mechanical performances of a novel stitched sandwich panel structure (SSPS), which contains two Al₂O₃/Al₂O₃ woven composite face-sheets, an aerogel heat-insulation core, and several mullite z-pin fiber yarns. Four types of experiments were conducted, including out-of-plane compression and tension, interlaminar shear, and three-point bending, to reveal the effects of stitching density, stitching yarn twist, and strands on the mechanical performances of the SSPS. Experimental results indicated that the stitching parameters have significant effects on the mechanical properties of the SSPS, in particular, the strengths and failure features. This study indicated that perforation and stitching are convenient and efficient approaches to promote the performances of panel-core-panel sandwich structures.