Viscoelastic stress analysis of adhesively bonded joints

Existing closed form solutions for the stress analysis of the single lap joint were studied intensively, and methods of analysis and assumptions between the analyses of Goland and Reissner, Hart-Smith and Delale and Erdogan were compared. The existing SAAS3V finite element program was modified to accommodate additional mesh generation and plotting capabilities. The modified version, SAAS3VP, was used for performing linear elastic and viscoelastic analyses on the single lap joint, and a non-linear viscoelastic analysis on the thick adherend specimen. Metlbond 1113 and Araldite adhesive properties were used in the linear elastic and viscoelastic analyses, respectively. FM-73 adhesive properties were used in the non-linear viscoelastic analysis. Time-dependent shear moduli were calculated from the results of the latter analysis and compared with the experimentally obtained shear modulus of Krieger. Interface layers were defined in both the single lap and thick adherend analyses and the influence of changing the interface layer stiffness on adhesive stresses was also investigated.