[SY-E14] Symposium E-14

[SY-E14] An analytical model of the peeling forces at edges of multilayers subjected to temperature variations

^○Chengyin Zhang², Neng-Hui Zhang^1,2 (1.Department of Mechanics, College of Sciences, Shanghai University, China, 2.Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, China)

Due to different mechanical properties of various materials in a multilayered beam or plate, there is a thermal mismatch between layers when the structural temperature changes. The interfacial peeling stresses and interfacial shear stresses caused by the thermal mismatch can result in a delamination between layers, especially in the edge regions, and this can lead to the damage of a layered structures. Because of the complexity of the boundary stresses, it is difficult to obtain exact a closed-form solution for these interfacial thermal stresses in the edge regions. Therefore, instead of the precise stress field, we divert to the interfacial peeling moment integrated by the localized interfacial normal stress and the interfacial shear force integrated by the localized interfacial shear stresses. The in-plane stresses in terms of Zhang’s two-variables are integrated across the cross section in the far-field region in order to formulate the interfacial peeling moment and interfacial shear force in the edge regions for the multilayered beam system. To verify the applicability of the analytical model of the peeling forces (including interfacial peeling moment and shear force), an aluminum-silicon bimaterial beam in electronic devices is taken as a calculating sample. The influence of the thickness and Young’s modulus of the film on the peeling forces are discussed. And the analytical predictions have a good agreement with the results from a finite-element analysis.