碳纤维/树脂基复合材料曲壁蜂窝夹芯结构的三点弯曲性能

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

为研究碳纤维复合材料(CFRP)曲壁蜂窝结构在三点弯曲载荷作用下的承载特性与失效模式,对不同芯层高度、面板厚度的结构进行了理论预报、数值模拟及试验.首先,根据夹芯结构的主要失效模式,提出了相应的理论预报公式,并绘制了失效机制图;其次,建立了CFRP曲壁蜂窝夹芯结构的有限元仿真模型,对其在三点弯曲载荷作用下的典型失效行为进行模拟;最后,通过模压成型工艺制备了不同尺寸的CFRP曲壁蜂窝夹芯结构,并将试验结果与理论、模拟结果进行比较.结果表明,蜂窝夹芯结构承载能力与芯层高度、面板厚度密切相关,结构芯层及面板刚度随其尺寸的减小而下降,导致结构失效模式由面芯脱黏失效变为面板压溃失效.

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.