A closed-form solution to the problem of crack identification for a multistep beam based on Rayleigh quotient

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:150

Article

Khiem, N. T.^1,2  Tran, T. H.²  Ninh, V. T. A.³ 

[1] Ho Chi Minh City Univ Technol HUTECH, Ctr Interdisciplinary Res, 475A Dien Bien Phu St, Ho Chi Minh City, Vietnam

[2] VAST, Inst Mech, 264 Doi Can, Hanoi, Vietnam

[3] Univ Transport & Commun, Hanoi, Vietnam

关键词: Multistep beam;    Crack detection;    Natural frequencies;    Rayleigh quotient;   

DOI  :  10.1016/j.ijsolstr.2018.06.010

来源: Elsevier

【 摘 要 】

In the present paper, the problem of detecting unknown number of cracks is solved in a closed form for a multistep beam. First, general Rayleigh quotient is established for a multistep beam with an arbitrary number of cracks and boundary conditions. Then, it is used for obtaining an explicit expression of natural frequencies through crack parameters for cantilever multistep beams. The obtained expression is straightforward for calculating natural frequencies of a multistep beam with an arbitrary number of transverse cracks and enables to develop an efficient procedure for detecting unknown number of cracks in the beam structure. Numerical examples show that the Rayleigh quotient is really a useful tool for modal analysis and identification of cracked multistep beams. An experimental study is accomplished for a two-step cracked cantilever beam to validate the theoretical development. (C) 2018 Elsevier Ltd. All rights reserved.

【 授权许可】

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