Experimental Vibration Analysis for Viscoelastically Damped Circular Cylindrical Shell Using Nonlinear Least Square Method |
Min Cheon-Hong,Park Han-Il,Bae Soo-Ryong |
Graduate School of Korea Maritime University,Division of Ocean Development Engineering Korea Maritime University,Agency for Defence Development |
비선형 최소제곱법을 이용한 점탄성 감쇠를 갖는 원통셀의 실험진동해석 |
민천홍,박한일,배수룡 |
한국해양대학교 대학원,한국해양대학교 해양개발공학부,국방과학연구소 |
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© 2008 The Korean Society of Ocean Engineers
Open access / Under a Creative Commons License
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Keywords:
Curve fitting method, Experimental modal analysis, Circular cylindrical shell, Modal parameter, Modal identification, Nonlinear least square method |
핵심용어:
곡선맞춤법, 실험모드해석, 원통셀, 모드변수, 모드추출, 비선형 최소제곱법 |
Abstract |
It is a recent trend for advanced ships and submarines to incorporate composite structures with viscoelastically damping material. Much research has been done on curve-fitting techniquesto identify vibration characteristic parameters such as natural frequencies, modal damping ratios, and mode shapes of the composite structure. In this study, an advanced technique for accurately determining vibration characteristic of a circular cylindrical shell-attached viscoelastically damping material is used, based on a multi-degree of freedom (MDOF) curve-fitting method. First, an initial value is obtained by using a linear least square method. Next, using the initial value, the exact modal parameters of the composite circular cylindrical shell are obtained by using a nonlinear least square method. Results show computation time is greatly decreased and accurate results are obtained by the MDOF curve-fitting method. |
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