Shape bifurcation of an elastic wafer due to surface stress

IntroductionSurfacestressisresponsibleformanymesoscopicalphenomenainmaterialsandthushasbeenstudiedextensively[1～ 5 ].Althoughtheabsolutevalueofsurfacestressofasolidcurrentlycannotbeobtainedbyexperiments,themethodformeasuringitschangehasbeenwellestablished .Theprincipleisratherclear.Whenthesurfacestressononesurfaceofawafer,eitherfreestandingorclampedatoneend ,changesduetocertainreasonssuchasadsorption ,thedifferencebetweenthesurfacestressonthissurfaceandthatontheoppositeoneresultsinabendingmom…     

表面应力引起的弹性薄膜形状分叉

此工作致力于无约束各向同性弹性薄膜在表面应力发生变化时几何非线性变形分析。基于能量的考虑,导出了曲率与表面应力变化量的关系。与已有线弹性分析结果的显著区别是,当薄膜很薄而上下表面应力差足够大时,薄膜曲率的解不再唯一,而会发生分叉。