Three-Point Bending Properties of Carbon Fiber Reinforced Polymer Composite Honeycomb Sandwich Structures With Curved Wall

Abstract

In order to analyze the load-bearing capacities and failure modes of carbon fiber reinforced polymer composite honeycomb sandwich structures with curved wall under 3-point bending loads, theoretical prediction, numerical simulation and tests were carried out for structures with different core heights and facesheet thicknesses. According to the main failure modes of sandwich structures, different theoretical prediction formulas and failure mechanism diagrams were firstly made. Then, the numerical simulation model for the CFRP sandwich structure with a honeycomb core was established to simulate its failure behavior under the 3-point bending load. Finally, different-size CFRP sandwich structures were fabricated by a molding process, and the experimental results were compared with theoretical and simulation results. The results show that, the bearing capacity of the sandwich structure is positively correlated with the core height and the facesheet thickness, and the core and facesheet stiffness decrease with the structure size, which results in the structural failure modes changing from core-facesheet debonding to face crushing.