摘要
基于凹角蜂窝的负Poisson比拉胀效应,对其屈曲力学性能进行了有限元仿真分析,得出区别于传统正六边形蜂窝结构的两种屈曲模态.为了研究这两种屈曲模态的屈曲强度以及产生机理,采用梁柱理论对其进行了理论分析.根据梁-柱方程和平衡关系建立包含杆端弯矩和杆端转角的方程组,利用屈曲临界条件建立稳定方程,得到屈曲强度的解析表达式.采用增材制造技术打印凹角蜂窝试件,对其屈曲性能进行实验验证.结果表明,双轴加载条件的不同会引起屈曲模态的显著变化;区别于传统蜂窝结构,凹角蜂窝的负Poisson比拉胀效应使其在双轴受拉状态下发生屈曲失稳;双轴应力状态下的屈曲失效界面分析获得了典型的屈曲分岔现象.这项研究对凹角蜂窝因失稳而破坏以及利用凹角蜂窝失稳实现特殊力学性能的研究具有一定的指导意义.
Based on the negative Poisson’s ratio effect of the re-entrant honeycomb,the finite element simulation of its buckling mechanical properties was carried out,and 2 buckling modes other than those of the traditional hexagonal honeycomb structures were obtained.The beam-column theory was applied to analyze the buckling strength and mechanism of the 2 buckling modes,where the equilibrium equations including the beam end bending moments and rotation angles were established.The stability equation was built through application of the buckling critical condition,and then the analytical expression of the buckling strength was obtained.The re-entrant honeycomb specimen was printed with the additive manufacturing technology,and its buckling performance was verified by experiments.The results show that,the buckling modes vary significantly under different biaxial loading conditions;the re-entrant honeycomb would buckle under biaxial tension due to the auxetic effect,being quite different from the traditional honeycomb structure;the typical buckling bifurcation phenomenon emerges in the analysis of the buckling failure surfaces under biaxial stress states.This research provides a significant guide for the study on the failure of re-entrant honeycomb structures due to instability,and the active application of this instability to achieve special mechanical properties.
作者
周世奇
侯秀慧
邓子辰
ZHOU Shiqi;HOU Xiuhui;DENG Zichen(School of Mechanics,Civil Engineering and Architecture,Northwestern Polytechnical University,Xi’an 710129,P.R.China;MIIT Key Laboratory of Dynamics and Control of Complex Systems,Xi’an 710072,P.R.China)
出处
《应用数学和力学》
CSCD
北大核心
2023年第1期12-24,共13页
Applied Mathematics and Mechanics
基金
国家自然科学基金(11972287
11872303)。
