Interlaminar stress analysis of piezo-bonded composite laminates using the extended Kantorovich method

• An iterative free edge stress analysis of piezo-bonded composite laminates is proposed.
• Interlaminar stresses are concentrated at the free edge under piezoelectric excitation.
• The stresses obtained by the extended Kantorovich method are verified using the results of 3D FEM.
• For the general application, cross-ply, angle-ply and quasi-isotropic laminates are investigated.
• The stress concentration due to piezo actuation is accurately predicted by the proposed approach.

An iterative method has been applied to analyze the free edge interlaminar stresses of piezo-bonded composite laminates. Electric fields are applied to two symmetrically bonded piezo actuators that can generate induced strain, resulting in pure extension of the whole structure. The stresses, which satisfy the traction-free and free edge boundary conditions, are obtained by taking the principle of complementary virtual work, and conducting the extended Kantorovich method. In order to obtain accurate interlaminar stress distributions, static and kinematic continuity conditions are applied at the interfaces between plies through iterations. The stress components were obtained under the plane strain assumption as well as antiplane shear assumption. The results were compared with those obtained by the finite element method, to demonstrate the validity of the proposed method. Through the iteration processes, the interlaminar stresses converged well, and predicted maximum peak stress at the interface of piezo and composite layers. The present method provides accurate stresses distribution near the free edges, of piezo-bonded composite laminates.