金属纤维钩织复合结构压缩行为分析

目的 针对金属薄壁复合管在轴向压缩时初始峰值载荷高、吸能效果不佳、结构耐撞性不好等问题，研究金属纤维钩织复合结构以及填充6063铝合金管试件的轴向准静态压缩行为和吸能特性。方法 利用短针钩织与烧结工艺制备不同孔隙率的金属纤维钩织结构，将它们填充到6063薄壁管之后，在万能试验机上进行轴向压缩试验，引入评价指标，对试验数据进行处理分析。结果 孔隙率为85.9%、87.9%、89.4%的金属纤维钩织结构的初始峰值力分别为0.48、0.38、0.32 kN，平均压缩力分别为0.72、0.55、0.45 kN。它们的初始峰值力和平均压缩力都非常小，都小于0.8 kN。然而，它们的压缩力效率非常高，分别为1.5、1.45、1.41。初始峰值力、平均压缩力和压缩力效率均随孔隙率的增加而减小。这一特性有利于提高结构的耐撞性，表明不存在初始冲击效应，能够直接进入吸能阶段。结论 通过填充金属纤维钩织结构，可以在初始峰值力几乎没有增加的情况下提高6063管材的准静态耐撞性。此外，钩织结构孔隙率对金属纤维钩织结构的准静态力学行为有明显影响。

Compression Behavior Analysis of Metal Fiber Crocheted Composite Structures

The work aims to study the quasi-static compression behavior and energy absorption characteristics of metal fiber crocheted composite structure and 6063 aluminum alloy pipe specimen filled with such structure, so as to solve the problems of high initial peak load, poor energy absorption effect and poor crashworthiness of metal thin-walled composite pipe during axial compression. The metal fiber crocheted structures with different porosities were prepared by short-needle crochet and sintering process, and after such structures were filled into the 6063 thin-walled pipe, the axial compression test was carried out on the experimental platform of the universal testing machine. Evaluation indexes were introduced and the test parameters were processed and analyzed. The results indicated that the initial peak force of metal fiber crocheted structures with porosity of 85.9%, 87.9% and 89.4% was 0.48, 0.38 and 0.32 kN respectively, and the average compressive force was 0.72, 0.55 and 0.45 kN respectively. Their initial peak force and average compressive force were very small, less than 0.8 kN. However, they showed very high compressive force efficiencies of 1.5, 1.45, and 1.41, respectively. The initial peak force, average compressive force and compressive force efficiency all decreased with the increase of porosity. This property was conducive to improving the crashworthiness of the structure, indicating that there was no initial impact effect and it could directly enter the energy absorption stage. By filling the metal fiber crocheted structure, the quasi-static crashworthiness of 6063 pipe can be improved with little increase in initial peak force. Moreover, the porosity of crocheted structure has obvious effect on the quasi-static mechanical behavior of metal fiber crocheted structure.