Experimental Vibration Analysis of a Super-Structure Model Using Curve Fitting Method

Oh, Chang-Geun; Je, Hae-Kwang; Park, Sok-Chu

Journal of Navigation and Port Research 2002;26(3):281-287.
Published online August 31, 2002.

곡선맞춤법을 이용한 선체상부구조 모델의 진동해석

오창근, 제해광, 박석주

Experimental Vibration Analysis of a Super-Structure Model Using Curve Fitting Method

Chang-Geun Oh, Hae-Kwang Je, Sok-Chu Park

Abstract

It might be true that both experimental and analytic techniques have been developed in the vibration analysis and engineering. It could not be said, however, that the experimental method has been also developed as much as analytic method, such as Finite Element Method. One of the reasons is that computation time becomes longer and that the solution often diverges depending on the choice of initial value in solving nonlinear equation. The equation in experimental modal analysis is usually composed of the nonlinear term of natural frequency and modal damping ratio, and the linear one of equivalent stiffness. In this study, the nonlinear terms were solved first, and then the linear term was obtained. The experimental modal parameters were estimated, applying the developed experimental modal analysis (curve-fitting method) to the super-structure model. In addition, the number of modes and modal damping ratio could be easily determined by the developed program with the application of graphical techniques and with easy handling mouse button.

Key Words: experimental modal analysis;curve-fitting method;modal parameter;modal damping ratio