【作者】 李伟；

【导师】 罗俊；

【作者基本信息】 华中科技大学 ， 固体力学， 2014， 硕士

【摘要】 薄膜材料通常附着在比较厚的柔性基体上发挥作用，在受到外界压缩载荷作用下基体表面的薄膜经常发生屈曲和分层，进而造成结构的破坏。在以往的研究中，屈曲和分层作为两种常见问题分别得到了广泛研究，而最近的研究表明，薄膜的屈曲可以导致与基体之间的分层，屈曲和分层可以同时存在。本文在前人的研究基础上，通过有限元方法研究了柔性基体上薄膜的屈曲以及屈曲所引起的分层现象。在不考虑分层的情况下，我们研究了薄膜/基体的泊松比和大小尺寸对屈曲临界载荷的影响，考虑了柔性基体不同超弹性本构关系描述下屈曲波长和波幅与载荷之间的关系，讨论屈曲表面形貌与三角函数之间的关系，并且对二者之间的差异进行了定量分析。在考虑分层的情况下，通过在薄膜和基体界面之间引入内聚力单元来模拟薄膜与基体之间的分层，研究了薄膜屈曲引起的分层现象。考虑了界面参数中界面刚度、界面极限强度、能量释放率对薄膜分层以及分层扩展的影响，得出超弹性基体上薄膜分层临界载荷的近似公式。讨论了分层对薄膜屈曲形貌的影响，并与三角函数进行了对比。更多还原

【Abstract】 Compressing a thin elastic film attached to a thick compliant substrate can lead tobuckling instability and delamination, thus causing failure of the structure. Twocommonly observed modes, buckling and buckle-delamination, have each been analyzedseparately in previous studies. Recent experiments have observed that the two modes canco-exist and co-evolve. In this paper, by analytical and finite element methods, we presenta study on concomitant buckling and buckle-delamination for an elastic film on a highlycompliant substrate.Without delamination, we present an analytical solution for buckling that takes intoaccount the effect of Poisson’s ratio and size of the substrate. By using differentsuper-elastic constitutive model, we investigated the buckling wavelength and amplitudewhen the load increases. Then, we discussed the relationship between the surfacetopography and trigonometric functions, and the differences between them werequantitatively analyzed.Considering delamination, we introduced cohesive zone model (CZM) to simulate thedelamination between the substrate and the film, and the buckling induced delaminationwas studied. In this part, some factors which affect on interfacial debonding areconsidered, such as interface stiffness, ultimate strength of the interface, the energy releaserate, then an approximate formula is derived to predict initiation of buckle-induceddelamination. Compared with the trigonometric function，the effect of delamination onbuckling morphologies of the films were discussed.更多还原