铝圆管蜂窝材料制备及其准静态压缩性能研究

Fabrication and Quasi-static Compression Performance of Aluminum Circular Honeycomb

圆管蜂窝的制备是制约其发展和应用的一个关键问题。采用钎焊方法,设计钎焊工艺流程,制备铝圆管蜂窝材料,为蜂窝材料的生产提供了一种方法。对制备的蜂窝材料进行了准静态压缩试验,研究圆管的变形特征和力学响应。采用有限元对试验进行模拟,考虑钎焊焊缝和制备缺陷影响,建立圆管蜂窝的有限元模型,发现有限元模拟应力-应变曲线和变形过程与试验结果吻合良好。制备缺陷导致蜂窝提前密实化,对力学性能的影响不可忽略。在此基础上对不同壁厚圆管蜂窝进行了准静态压缩模拟,同时基于弹塑性理论推导了蜂窝的等效弹性模量和塑性初始屈服应力的计算公式,结果表明考虑焊缝影响时解析解和模拟结果相近,都要高于相同条件下不考虑焊缝的理想解,且随着相对密度的增加,焊缝的影响作用增大。

The fabrication and manufacturing of circular honeycomb is a critical technology that has play an important role on its development and application of industry.Aluminum circular honeycombs have been made by brazing method with specific processes and parameters,which is an invention for the porous structure manufacturing.Quasi-static compression performance testing of the honeycombs is carried out to study the deformation characteristics and mechanical behaviors of the circular tubes of honeycombs.The finite element model of circular honeycomb is established considering the influence of brazing seam and fabrication defects.It is found that the stress-strain curves and deformation processes simulated by the finite element method are in good agreement with the test results.The welded defects causes the honeycomb to be dense ahead of time,and the effect of defects on the mechanical properties cannot be ignored.On this basis,the quasi-static compression simulation of the circular honeycombs is carried out with different wall thickness,and the calculation formulas of the equivalent elastic modulus and the plastic initial yield stress of the honeycomb are derived based on the elastic-plastic theory.The results show that the analytical solution is agreed with that of numerical cases,with considering the influence of the welded joints,which is higher than the ideal solution without considering the welded joints.In addition,the influence of welded joints on the mechanical behavior of circular honeycomb is more and more obvious with the increasing of material relative density.