Compression properties of carbon fiber reinforced polymer grid sandwich structure

Abstract

Carbon fiber reinforced polymer (CFRP) grid sandwich structure with four different grid configurations was prepared using the interlocking assembly process in the present work. All test specimens were subjected to quasi-static out-of-plane uniform compression. The equivalent density, height, geometric configuration, and other factors of the structural core layer were analyzed, and their effects on the failure mode, damage mechanism, and energy absorption characteristics of CFRP grid sandwich structure were discussed. The results showed that there are four distinct stages in the load versus displacement curve of CFRP grid sandwich structure specimens subjected to uniform compression, namely, preloading stage, elastic stage, load drop stage, and platform stage. The main failure modes of CFRP grid sandwich structure are the local buckling and compression fracture of the core rib. The failure load, compression strength, breaking absorbed energy, and specific absorbed energy of CFRP grid sandwich structure are positively correlated with the equivalent density of the structure core layer, and negatively correlated with the height of the structure core layer. When the equivalent density of the core layer of the Mixed CFRP grid sandwich structure was increased by 10 kg/m3, the compressive strength and specific energy absorption of the structure increased by about 5.08 MPa and 186.79 mJ, respectively, and when the core layer height was increased by 10 mm, the compressive strength and specific energy absorption decreased by about 12.04 MPa and 67.39 mJ, respectively; The strength and stability of the Mixed CFRP grid sandwich structure are significantly higher than those of the Triangular, Diamond, and Square CFRP grid sandwich structures.