Indonesia Conference Directory

Partially debonding at the skin/core interface during fabrication and/or in-service life is recognized to be the primary pre-failure modes in the ship sandwich structure. The vibration-based damage detection approach is a promising option to ascertain damage existence. The numerically dynamic behavior subjected to harmonic loading of partially debonded sandwich is investigated using two model discretizations: spring element and real contact model. The material consists of two thin steel skins bonded to the lightweight core of resin/clamshell powder. The considerable influence of the debonding ratio, location, shape on the structural modal parameters (natural frequency, mode shape, and structural time history dynamic responses) based on two model discretizations is rigorously compared. To be confident in results of the numerical analysis, an experimental modal analysis of initial model is carried out to validate the correctness of the FE model. It is recognized that the spring element method is less convenient for handling the debonding problem than the surface contact definition. The result shows that the higher natural frequencies and mode shapes are more sensitive to the debonding presence. The results demonstrate that both methods can be useful for assessing practical problems related to the non-destructive damage detection in ship structure.