多胞圆管夹芯组合板落锤冲击试验及数值仿真

Drop hammer impact tests and numerical simulation of multi-cell circular tube sandwich composite panel

为了应对煤矿巷道冲击地压下支架结构破坏严重的问题,提出了一种多胞圆管夹芯组合板。该组合板可与煤矿巷道金属支架结合,通过溃缩变形吸能共同抵御冲击荷载。共设计了4个不同芯层厚度夹芯组合板试件的落锤冲击试验,并建立了有限元模型,基于试验验证了该数值模型,开展了多胞圆管夹芯组合板的冲击响应和吸能特性的参数分析。研究结果表明,冲击作用下,多胞圆管夹芯组合板面板呈现圆盘状凹陷,芯层胞体和十字肋发生了褶皱和下陷变形,各个腔室协同工作、相互支撑,并通过塑性变形吸能。同时底部冲击反力的峰值总是滞后且低于落锤冲击荷载峰值,在多次冲击条件下,该组合板也能展现出良好的吸能缓冲效果。多胞圆管夹芯组合板可吸收超过90.00%的冲击能量,其中65.00%以上能量由芯层结构吸收。芯层厚度从0.5 mm增加到2.0 mm,芯层部分吸收能量的占比增大了24.17%,相反面板吸能效率递减,减幅为17.17%,芯层厚度减小可降低峰值冲击荷载,芯层厚度为1.0 mm时吸能效果较好。面板厚度对吸能性能影响较小,建议其厚度选择与芯层厚度相近。冲击能量一定情况下,改变落锤质量和冲击速度对结构动力冲击性能和吸能效率的影响很小。

Here,aiming at the problem of serious failure of support structures under impact ground pressure in coal mine tunnel,a multi-cell circular tube sandwich composite panel was proposed.This composite panel could be combined with metal supports in coal mine tunnel to absorb energy through collapse deformation,and jointly resist impact load.4 sandwich composite panel specimens with different core layer thicknesses were designed for drop hammer impact tests,and a finite element model was established.This numerical model was verified based on tests.The parametric analyses of impact responses and energy absorption characteristics of the composite panel were performed.The study results showed that under impact condition,the multi-cell circular tube sandwich composite panel presents a disc-shaped depression,and core layer cell bodies and cross ribs undergo wrinkling and sinking deformation;various chambers collaboratively work,support each other and absorb energy through plastic deformation;meanwhile,peak values of bottom impact reaction forces always lag behind and are lower than peak values of hammer impact load;under multiple impacts condition,this composite panel can also exhibit good energy absorption and the buffering effect;this composite panel can absorb over 90.00%of impact energy,over 65.00%of energy is absorbed by core layer structure;if core layer thickness increases from 0.5 mm to 2.0 mm,the proportion of energy absorbed by core layer increases by 24.17%,on the contrary,energy absorption efficiency of panel decreases by 17.17%;reducing core layer thickness can reduce peak impact load,the energy absorption effect is better when core layer thickness is 1.0 mm;effects of panel thickness on energy absorption performance are smaller,and it is recommended to choose its thickness similar to that of core layer;under a certain impact energy,changing weight and impact velocity of hammer has little effect on dynamic impact performance and energy absorption efficiency of panel structure.