X-cor夹层结构低速冲击实验和数值模拟研究

发布时间：2019-01-24 16:09

【摘要】：X-cor泡沫夹层结构是一种通过Z-pin技术增强泡沫夹芯的新型高性能夹层结构。在低速冲击下,X-cor夹层结构损伤失效机制复杂,通过在不同能量阶段对X-cor夹层结构失效行为进行分析,讨论Z-pin植入体积分数和泡沫芯材密度对失效行为的影响。低速冲击试样规格为Z-pin直径0.5 mm、植入角度为22°,分别改变泡沫类型和Zpin植入体积分数进行实验,结果表明:6 J冲击能量下,冲击能量主要由面板分层承担,相对于未植入Z-pin试样,随着Z-pin植入体积分数的升高,面板分层面积最多减少了45.1%,而泡沫密度对分层面积影响不大;12 J冲击能量下,部分Z-pin发生失效,通过剩余压缩强度比发现,随着Z-pin植入体积分数的增加,剩余压缩强度比先增大后减小,植入体积分数为0.42%时最高,而此时泡沫密度增加,剩余压缩强度比也随之增加;当能量到达18 J时,芯材开始出现剪切裂纹,同时吸收大部分能量,较弱的芯材剩余压缩强度比大,而Z-pin植入体积分数越大,剩余压缩强度比反而越小。采用数值模拟的方法建立低速冲击模型,并将冲击后的结果直接传递应用于剩余压缩强度模型中,得到的结果比实验值偏高25%~29%。
[Abstract]:X-cor foam sandwich structure is a new type of high performance sandwich structure which enhances foam core by Z-pin technology. The damage and failure mechanism of X-cor sandwich structure under low speed impact is complex. The effects of volume fraction of Z-pin implantation and density of foam core on failure behavior of X-cor sandwich structure are discussed by analyzing the failure behavior of X-cor sandwich structure at different energy stages. The low velocity impact specimen was tested with Z-pin diameter 0.5 mm, implantation angle of 22 掳, the foam type and the volume fraction of Zpin implantation were changed respectively. The results showed that the impact energy was mainly borne by the panel layers under the impact energy of 6 J. Compared with the unimplanted Z-pin specimen, with the increase of the volume fraction of Z-pin implantation, the lamination area of the panel decreased by 45.1%, while the foam density had little effect on the stratified area. At 12 J impact energy, partial Z-pin failure occurred. It was found that with the increase of Z-pin implantation volume fraction, the residual compressive strength ratio increased first and then decreased, and reached the highest at 0.42% implantation volume fraction. At the same time, the density of foam increases, and the ratio of residual compressive strength also increases. When the energy reaches 18 J, the core begins to appear shearing cracks and absorbs most of the energy at the same time. The lower the residual compressive strength ratio of the core is, the larger the volume fraction of Z-pin implantation is, the smaller the residual compressive strength ratio is. The low speed impact model is established by numerical simulation, and the results after impact are directly transferred to the residual compression strength model. The obtained results are 25% higher than the experimental values.
【作者单位】：南京航空航天大学材料科学与技术学院;
【基金】：航空科学基金项目(2015ZE52049)
【分类号】：TB332

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