Wrinkling of a bilayer resting on a soft substrate under in-plane compression

• Published in: Philosophical magazine (Abingdon, England) Vol. 92; no. 12; pp. 1554 - 1568
• Main Authors: Jia, Fei, Cao, Yan-Ping, Liu, Tian-Shu, Jiang, Yi, Feng, Xi-Qiao, Yu, Shou-Wen
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis Group 21.04.2012; Taylor & Francis
• Subjects: bilayer film; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Mechanical and acoustical properties; pattern transformation; Physical properties of thin films, nonelectronic; Physics; soft substrate; surface patterning; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); wrinkling; Thickness; Finite element method; Elastic modulus; Compressive stress; Calcium selenides; Numerical analysis; Composite materials; Digital simulation; Soft magnetic materials; Switching; Bilayers
• ISSN: 1478-6435; 1478-6443
• DOI: 10.1080/14786435.2011.652691

The wrinkling problem of a bilayer film resting on a soft substrate under in-plane compression is investigated via theoretical analysis and numerical simulations. Such a system may undergo two different wrinkling modes, namely surface wrinkling of the top single layer on a composite substrate or bilayer wrinkling on a homogeneous substrate, depending on the geometric and material parameters. In the present paper, a theoretical solution is first derived for the former case, while a solution available in the literature is applied for the latter. The solution derived here can degenerate both to the classical solution for a stiff layer resting on a semi-infinite soft substrate and that for a stiff layer lying on a compliant substrate of finite thickness. A series of finite element simulations are performed to demonstrate the accuracy of the theoretical solution. In addition, it is found that, at a given compressive strain, a certain change in the elastic modulus of the intermediate layer may lead to a dramatic surface pattern transformation between the two wrinkling modes, indicating a novel approach to realise surface pattern switching.