Application of the random decrement technique in the identification of damage on submerged stiffened plates


The dynamic response of an intact and damaged stiffened plate model vibrating in air and in water was investigated experimentally and analytically. The random decrement (randomdec) technique was used to calculate experimentally randomdec signatures of the model. A finite elemen model was formulated to generate the numerical free vibration responses of the model. The numerical free vibration responses were then compared with the experimental randomdec signatures. The sensitivities of the experimental randomdec signatures and the analytical free vibration responses to indicate various lengths of crack were analyzed. The results indicated that the randomdec signatures and the free vibration responses could be used to identify the presence of damage and water by changing the signature and response strength, and decreasing the natural frequency. Keywords: Stiffened palte model, randpm decrement technique, randomdec signature.Achmad Zubaydi; Jurusak Teknik Perkapalan FTK,ITS