Investigation of Debonding Effect on Response of Sandwich Panel Structure Columns Reinforced by Composite Fibers

The delamination and debonding phenomena of the layer are two of the defects that occurs in composite-reinforced sandwich structures. In this paper, the debonding and debonding growth of buckling load has been investigated. Debonding growth is modeled by cohesive elements with defect code in Abaqus finite element software. In this study, debonding and growth of debonding between composite and core layers has been investigated. In this model, three simulations were performed and the results were compared with the results of previous research. The first model is a structure with no defect, the second considers the initial defect of debonding, and the third model is the structure considering the initial defect of debonding and its growth. In the second and third models, the initial debonding is considered to be 25 and 50 mm in length. The results in the second and third models indicate two stages in the load-displacement diagram that justify the occurrence of local buckling at the site of debonding. As expected, an increase in the length of the initial debonding would reduce the local and global buckling load. In contrary to previous research, considering the growth of debonding and the use of defect code, the results of load-displacement are closer to the empirical results.