Effect of residual stresses on wave propagation in adhesively bonded multilayered MEMS structures

The paper investigates propagation of stationary plane longitudinal and transverse waves along the layers in adhesively bonded multilayered structures for MEMS applications in the presence of residual stresses. The multilayered structure is assumed to consist of the infinite amount of the periodically recurring layers made of two different materials possessing significantly dissimilar properties: conductive metal layer and insulating adhesive layer. It is assumed that the mechanical behaviour of both materials is nonlinear elastic and can be described with the help of the elastic Murnaghan potential depending on the three invariants of strain tensor. The problem is formulated in the framework of the three-dimensional linearized elasticity theory of finite initial deformations. The influence of the residual stresses in each layer and of the ratio of the layer thicknesses on the normalized velocity of propagation of the stationary plane wave is examined and discussed. It is found that for some multilayered structures there exist such values of the ratio of the layer thicknesses that wave velocities do not depend on the magnitude of residual stresses but are equal to the corresponding wave velocities in the unstressed structure.