金属与CFRP穿透增强连接结构低速冲击损伤特性与结构优化

Low-velocity impact damage characteristics and structural optimization of metal and CFRP through-thickness reinforcement connection structures

为提升金属与复合材料连接结构的抗冲击性能,使用金属激光选区熔融技术制造金属突触结构,并与T300斜纹编织碳纤维复合材料(CFRP)共固化模压成型形成穿透增强连接结构,通过夏比摆锤冲击实验验证突触连接结构的抗冲击性,基于CFRP损伤形式与冲击吸收功对突触形貌等影响因素进行分析优化设计,并完成有限元仿真对比计算。实验结果表明:穿透增强连接方式能够避免由于开孔带来的金属应力集中与碳纤维切断,冲击吸收功为68.54 J,相较于螺栓连接提升216.1%;突触高度增加能够有效抑制复合材料冲击分层,突触特征尺寸、突触阵列密度影响复合材料内部缺陷,其冲击吸收功随着突触特征尺寸、突触阵列密度的增大先增加后减少;基于突触特征尺寸变化进行有限元仿真,仿真值与实验结果偏差小于17%,损伤形式基本一致。

To improve the impact resistance of metal and composite material joint structures,a metal synapse structure was manufactured using metal laser selective melting technology.The structure was cocured and molded with T300 twill woven carbon fiber-reinforced composite material(CFRP)to form a through-thickness reinforcement joint structure.The impact resistance of the synapse joint structure was verified through Charpy pendulum impact tests.Analysis and optimization of the synapse morphology were conducted based on CFRP damage patterns and impact absorption energy,as well as other influencing factors.Finite element simulations and comparative calculations were performed.The experimental results indicate that the penetration-enhanced joint method can prevent metal stress concentration and carbon fiber cutting caused by drilling holes.The impact absorption energy measures at 68.54 J,with a 216.1%improvement compared to the bolted connections.Increasing the height of the synapses effectively inhibits the composite material impact delamination.The synapse feature size and synapse array density affect internal defects in the composite material.With increasing synapse feature size and synapse array density,the impact absorption energy first increases to a point and then decreases.Finite element simulations based on synapse feature size variations showed that the simulation results deviated from the experimental results by less than 17%,and the damage form is highly consistent.