Predicting the Natural Frequency Response and Strain Energy Release Rate in Delaminated Adhesively Bonded Joints through Finite Element Analysis and Experimental Validation

Abstract

The primary focus of this research is to investigate the eigen values and strain energy release rate (SERR) of delaminated adhesively bonded single lap joint (SLJ). To achieve this, the study utilizes finite element analysis (FEA) to calculate eigenvalues for the adhesively bonded joints. These predictions are then compared with published data to validate the accuracy of the FEA model. Experimental work is also conducted on intact and delaminated bonded joints to further verify the FEA model reliability. Furthermore, the virtual crack closure technique (VCCT) in ABAQUS software was used to determine SERR values around the delamination front. Simulation solutions are obtained for various overlapping lengths (e.g., 25, 30, 35, and 40 mm) to predict the natural frequency under different boundary conditions, adhesive thickness ratios (a/h), and delamination shapes. Similarly, changes in the lamination scheme are considered to predict SERR values. It is observed that an increase in the adhesive thickness ratio leads to a decrease in the natural frequency response. Furthermore, a higher number of end restrictions contribute to improved outcomes. There is no significant impact of delamination shape on the natural frequency response. Notably, the cross-ply lamination sequence exhibits higher SERR values around the delamination front than other sequences.