Stress-strain analysis of adhesive-bonded single-lap composite joints under cylindrical bending

Abstract

An analytical study is proposed to develop an advanced model for determining the stress and strain distributions of adhesive-bonded composite single-lap joints under cylindrical bending. The anisotropic laminated plate theory and mechanics of composite materials are first used to derive the governing equations of the two bonded laminates. The entire coupled system is then obtained through assuming the peel stress between the two laminates. With the Fourier series and appropriate boundary conditions, the solutions of the system are obtained. Based on the proposed model, the stress and strain distributions of the adherends and the adhesive can be predicted. The coupling effects between tension and bending for asymmetric laminates are also included in this analysis. With the predicted stress distribution, the maximum peel and shear stresses, which are believed to be the most critical criteria on the joint strength, can be located and their values can be determined. An existing FEA code, �ALGOR�, is used as a comparison with this proposed analytical model. Based on the proposed analytical model, the maximum adhesive stress for different overlay lengths is predicted. An optimal overlay length is found to minimize the adhesive stress at the ends of the overlay. This study will be of interest to the aircraft industry since many advanced composite materials and adhesive-bonded lap joints are widely used in this field.