Tang Shan, Li Ying, Yang Yang, Guo Zaoyang
College of Aerospace Engineering, Chongqing University, 174 Shazheng Street, Chongqing, China.
Soft Matter. 2015 Oct 28;11(40):7911-9. doi: 10.1039/c5sm01614b. Epub 2015 Sep 1.
If a soft solid is compressible, its volume changes with imposed loading. The extent of the volume change depends on its Poisson's ratio. Here, we study the effect of the mechanical-driven volumetric change on buckling and post-buckling behaviors of a hard thin film perfectly bound on a compliant substrate through the theoretical analysis and finite element method. Poisson's ratio of the substrate has been chosen to be in the range of -1 to 0.5, allowing its volume change during deformation. We find that Poisson's ratio cannot only shift the critical strain for the onset of buckling, but also affect the buckling modes. When Poisson's ratio of the substrate is close to -1, the surface instabilities of the thin film can be suppressed and delayed to large deformation. The present study demonstrates a new way to control surface instabilities of a bilayered system by changing Poisson's ratio of the material.
如果软固体是可压缩的，其体积会随施加的载荷而变化。体积变化的程度取决于其泊松比。在此，我们通过理论分析和有限元方法研究了机械驱动的体积变化对完全粘结在柔性基底上的硬质薄膜的屈曲和后屈曲行为的影响。基底的泊松比已被选定在 -1 到 0.5 的范围内，以允许其在变形过程中发生体积变化。我们发现泊松比不仅可以改变屈曲起始的临界应变，还会影响屈曲模式。当基底的泊松比接近 -1 时，薄膜的表面不稳定性可以得到抑制，并延迟到大变形阶段。本研究展示了一种通过改变材料的泊松比来控制双层系统表面不稳定性的新方法。
