嵌锁式碳纤维/树脂基复合材料方形蜂窝夹芯结构的力学性能及损伤失效

Mechanical properties and damage failure of carbon fiber reinforced polymer composite sandwich structure with square honeycomb core using the interlocking method

设计并采用嵌锁组装工艺制备了碳纤维/树脂基复合材料方形蜂窝夹芯结构,开展了面外平压性能和三点弯曲性能试验研究,获得了夹芯结构在平压载荷作用下的破坏模式,分析了其损伤失效机制及吸能特性,讨论了在三点弯曲载荷作用下面板质量非对称性和槽口方向对夹芯梁的破坏模式及承载能力的影响。研究结果表明嵌锁式碳纤维/树脂基复合材料方形蜂窝夹芯结构在准静态压缩载荷下表现为从槽口附近纤维断裂到开槽侧肋板失稳断裂,再到未开槽侧肋板断裂和压溃的渐进式损伤破坏模式;压缩应力-应变曲线出现明显的二次应力平台,体现出夹芯结构优异的吸能特性;配置较厚的上面板及芯材长肋板槽口向上时,结构的承载能力和初始失效载荷更高。

Composite sandwich structure with carbon fiber reinforced polymer(CFRP)square honeycomb core was designed and fabricated using the interlocking method.The out-of-plane compressive performance and the threepoint bending performance of the sandwich structure were studied experimentally.The failure modes of the sandwich structure under out-of-plane compressive loading were obtained and the failure mechanism and energy absorption characteristics were analyzed.The influences of the asymmetry of the face sheet quality and the direction of the slots on the failure modes and bending strength of the sandwich beam under three-point bending loading were explored,respectively.The experimental results show that the sandwich structure under out-of-plane compressive loading exhibits the progressive failure mode:fiber fracture near the slots,bucking and fracture of the slotted part of ribs,and the fracture and crushing of the unslotted part of ribs.The compressive stress-strain curve has obvious two-stage plateau stress,which means the excellent energy absorption characteristics of the sandwich structure.The sandwich structure has the higher load-carrying capacity and initial failure loading for the thicker upper face sheet and the upward slots of the long ribs of the core.