An experimental investigation of nonlinear deformations in single-lap joints

Experimental analyses of a single-lap joint were performed to investigate the geometrically nonlinear deformations and adhesive stress distributions. Strain gages were used to record the nonlinear deformation of the specimen, and the full-field moiré interferometry technique was applied to determine surface deformations of the adherend and adhesive. Mechanics models of the single-lap joint were evaluated by comparing the experimental results with numerical and theoretical predictions of adherend moment and adhesive stress distributions. The three-dimensional nature of the adhesive peel stress on the free surface is documented in the moiré analysis. Some comments on the failure mechanism and stress singularities are made.