近日，西南交通大学的袁江宏&黄银及其研究团队取得一项新进展。经过不懈努力，他们揭示高长细比双稳结构轴向大冲程断裂不稳定性。相关研究成果已于2024年11月14日在国际知名学术期刊《理论与应用力学快报》上发表。

据悉，双稳态结构的机械突弹跳变失稳在许多实际应用中，如状态切换和能量转换，都具有重要意义。尽管存在多种能够发生突弹跳变失稳的双稳态结构，但对于具有高细长比的结构来说，要实现大行程的轴向突弹跳变失稳仍然很困难。

本文提出一种方法，仅通过有限数量、具有相对较低细长比的相同传统双稳态单元进行串联连接，即可构建出具有高细长比的弹性结构。为了实现大行程的轴向突弹跳变失稳，进一步引入了常见的剪刀机构作为刚性约束，以确保这些双稳态单元能够同步发生突弹跳变失稳。本文所实现的大行程突跳失稳具有全局稳健性，甚至对单个单元的局部不同步也不敏感。该设计为实现细长结构的大行程突弹跳变失稳提供了一种简单可行的方法，预计将在狭窄空间内的状态切换和能量转换中发挥特别重要的作用。

附：英文原文

Title: Large-stroke snap-through instability in the axial direction of a bi-stable structure with high slenderness

Author: Huan Zhou, Qian Sun, Haibin Xia, Yiwei Xiong, Youchao Yuan, Yin Huang, Jianghong Yuan

Issue&Volume: 2024-11-14

Abstract: Mechanical snap-through instability of bi-stable structures may find many practical applications such as state switching and energy transforming. Although there exist diverse bi-stable structures capable of snap-through instability, it is still difficult for a structure with high slenderness to undergo the axial snapthrough instability with a large stroke. Here, an elastic structure with high slenderness is simply constructed by a finite number of identical, conventional bistable units with relatively low slenderness in series connection. For realizing the axial snap-through instability with a large stroke, common scissors mechanisms are further introduced as rigid constraints to guarantee the synchronous snapthrough instability of these bi-stable units. The global feature of the large-stroke snap-through instability realized here is robust and even insusceptible to the local out-of-synchronization of individual units. The present design provides a simple and feasible way to achieve the large-stroke snap-through instability of slender structures, which is expected to be particularly useful for state switching and energy transforming in narrow spaces.

DOI: 10.1016/j.taml.2024.100561

Source: https://www.sciencedirect.com/science/article/pii/S2095034924000722