C型CFRP薄壁结构轴向吸能特性及其触发机制

Axial energy absorption characteristics and trigger mechanism of C-channel CFRP thin-walled structures

为了提高C型碳纤维增强树脂复合材料(CFRP)薄壁结构的耐撞性,对其在轴向压溃载荷作用下的吸能特性和失效行为进行研究。考虑层间分层效应,建立了C型CFRP薄壁结构的渐进损伤模型。采用二次名义应力失效和基于混合模式能量方法的非线性损伤演化准则分别对层间初始失效和损伤演化进行预测。针对该结构提出混合角度倒角触发和尖顶触发,对比分析了不同触发配置对C型CFRP薄壁结构耐撞性指标和失效模式的影响。结果表明混合角度倒角触发所对应的初始峰值随着混合角度的增大呈减小的趋势。通过减小混合角度尖顶触发与加载板在初始压溃阶段的接触面积,能够有效降低初始峰值。混合角度尖顶触发能够改善失效过程,对提高该结构的耐撞性有积极的影响。

To improve the crashworthiness of C-channel carbon fiber reinforced polymer(CFRP)thin-walled structures,the energy absorption characteristics and failure behavior of the structures under axial crushing load were studied.Considering the delamination effect,the progressive damage model of C-channel CFRP thin-walled structure was established.The quadratic stress failure and the nonlinear damage evolution criterion based on the mixedmode energy method were used to predict the initial interlaminar failure and damage evolution,respectively.For this structure,the hybrid-angle chamfer trigger and steeple trigger were proposed,and the effects of different trigger configurations on the crashworthiness index and failure mode of C-channel CFRP thin-walled structures were compared and analyzed.The results show that the initial peak load corresponding to the hybrid-angle chamfer trigger decreases with the increase of the hybrid angle;The initial peak load can be effectively reduced by reducing the contact area between the hybrid-angle chamfer trigger and the loading plate at the initial crushing stage;The hybridangle steeple trigger can improve the failure process and has a positive effect on improving the crashworthiness of the structure.