Stress concentration factors for bonded lap joints

Abstract

This paper is concerned with the stress analysis by the finite element method of a bonded, single, lap joint. Since the adhesive layer is of primary importance, the stresses occurring in it are presented. A modified version of the well-known Wilson stress analysis program is used for the case of plane stress. The total length beyond the lap is considered long compared to the lap length. Stress concentrations as functions of dimensionless, geometric and material parameters are presented. For a given load (7, the important maximum shearing stress concentration, rmax/(7, and tearing stress concentration <rmax/(T, are plotted as functions of l/t and rj/t for different values of E/EA, where I is the lap length, 77 is the adhesive thickness, t is the thickness of the material being bonded, and E and EA are the moduli of elasticity for the adherend and the adhesive, respectively.