Estimation method of singular stress field at adhesive bonded joint interface of dissimilar materials by inverse analysis of deformed shape data

This study applied a method of estimating the singular stress field at the bonded edge interface of dissimilar materials through inverse analysis on the deformed shape of the adherend. The inverse analysis used a mathematical model of the bonded member based on the free body diagram concept. Tikhonov regularization was applied in the inverse analysis to reduce the influence of displacement measurement errors on the estimated values. The Tikhonov regularization parameter was selected based on the behavior of the estimated singular stress field and singularity index. In order to verify the validity of the estimation method for adhesive joints combining dissimilar materials, peel tests were performed in numerical simulation, and the singular stress field at the bonded edge was estimated by the estimation method. The verification examined the influence of regulation parameters in the inverse analysis based on results obtained by introducing artificial measurement errors into the deformation shape data. The numerical simulation results showed that the stress distribution obtained from the inverse analysis was close to the correct value for all material combinations. Furthermore, the inverse analysis results remained close to the correct values even when measurement errors were introduced. These results demonstrate the effectiveness of the estimation method for predicting singular stress fields at bonded interfaces involving dissimilar materials. Additionally, the regularization parameter was shown to be effective in handling measurement errors.