Modal tailoring and closed-form solutions for rotating non-uniform Euler-Bernoulli beams

Sarkar, Korak and Ganguli, Ranjan (2014) Modal tailoring and closed-form solutions for rotating non-uniform Euler-Bernoulli beams. In: INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, 88 . pp. 208-220.

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Abstract

In this paper, the free vibration of a rotating Euler-Bernoulli beam is studied using an inverse problem approach. We assume a polynomial mode shape function for a particular mode, which satisfies all the four boundary conditions of a rotating beam, along with the internal nodes. Using this assumed mode shape function, we determine the linear mass and fifth order stiffness variations of the beam which are typical of helicopter blades. Thus, it is found that an infinite number of such beams exist whose fourth order governing differential equation possess a closed form solution for certain polynomial variations of the mass and stiffness, for both cantilever and pinned-free boundary conditions corresponding to hingeless and articulated rotors, respectively. A detailed study is conducted for the first, second and third modes of a rotating cantilever beam and the first and second elastic modes of a rotating pinned-free beam, and on how to pre-select the internal nodes such that the closed-form solutions exist for these cases. The derived results can be used as benchmark solutions for the validation of rotating beam numerical methods and may also guide nodal tailoring. (C) 2014 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
Additional Information:	Copyrights for this articles belongs to the PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Department/Centre:	Division of Mechanical Sciences > Aerospace Engineering(Formerly Aeronautical Engineering)
Date Deposited:	14 Dec 2014 10:03
Last Modified:	14 Dec 2014 10:03
URI:	http://eprints.iisc.ac.in/id/eprint/50427

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