The University of Southampton
University of Southampton Institutional Repository

Experimental study on a nonlinear vibration isolator based on a post-buckled inverted L-shaped beam

Experimental study on a nonlinear vibration isolator based on a post-buckled inverted L-shaped beam
Experimental study on a nonlinear vibration isolator based on a post-buckled inverted L-shaped beam
In this paper, the characteristics and the effectiveness of a nonlinear passive vibration isolator based on a post-buckled beam is investigated experimentally. The intended application is specifically isolation in the vertical direction where the isolator is required to be sufficiently stiff statically to bear the weight of the isolated mass. The isolator consists of two beams joined to form an inverted L-shape and the weight of the isolated mass is taken to act at the vertex. If the weight of isolated mass is larger than the buckling load of the L-shaped beam then the beam buckles in one of two modes, one of which is unstable. In this paper, the static restoring force of the unstable mode is measured and an appropriately selected coil spring is added to counteract the negative stiffness of the beam. The resulting system presents a dramatically lower stiffness to small excursions about its equilibrium position in its buckled state but maintains its static load bearing capability. Free vibration measurements are presented which show some amplitude dependency of the natural frequency for large amplitude motion. Low amplitude harmonic base excitation measurements are also conducted from which transmissibility measurements are obtained and compared with corresponding results from a Finite Element model. The fundamental resonance is about 80% lower than that achievable by a comparable linear isolator. However the performance of the prototype design is compromised by the presence of higher frequency internal resonances of the isolator, mitigation of which is the focus of ongoing work
Sasaki, Takumi
cf9957ce-fd5d-4c07-bba8-bc93b496f47e
Waters, Timothy P.
348d22f5-dba1-4384-87ac-04fe5d603c2f
Fujito, Koichi
089313cf-9ad9-469b-bead-48c1206c6435
Tsuji, Yumiko
0c800bd8-93d1-4a22-8b0e-fe3d8cfb2611
Sasaki, Takumi
cf9957ce-fd5d-4c07-bba8-bc93b496f47e
Waters, Timothy P.
348d22f5-dba1-4384-87ac-04fe5d603c2f
Fujito, Koichi
089313cf-9ad9-469b-bead-48c1206c6435
Tsuji, Yumiko
0c800bd8-93d1-4a22-8b0e-fe3d8cfb2611

Sasaki, Takumi, Waters, Timothy P., Fujito, Koichi and Tsuji, Yumiko (2014) Experimental study on a nonlinear vibration isolator based on a post-buckled inverted L-shaped beam. 12th International Conference on Motion and Vibration Control (MoViC), Japan. 10 pp .

Record type: Conference or Workshop Item (Paper)

Abstract

In this paper, the characteristics and the effectiveness of a nonlinear passive vibration isolator based on a post-buckled beam is investigated experimentally. The intended application is specifically isolation in the vertical direction where the isolator is required to be sufficiently stiff statically to bear the weight of the isolated mass. The isolator consists of two beams joined to form an inverted L-shape and the weight of the isolated mass is taken to act at the vertex. If the weight of isolated mass is larger than the buckling load of the L-shaped beam then the beam buckles in one of two modes, one of which is unstable. In this paper, the static restoring force of the unstable mode is measured and an appropriately selected coil spring is added to counteract the negative stiffness of the beam. The resulting system presents a dramatically lower stiffness to small excursions about its equilibrium position in its buckled state but maintains its static load bearing capability. Free vibration measurements are presented which show some amplitude dependency of the natural frequency for large amplitude motion. Low amplitude harmonic base excitation measurements are also conducted from which transmissibility measurements are obtained and compared with corresponding results from a Finite Element model. The fundamental resonance is about 80% lower than that achievable by a comparable linear isolator. However the performance of the prototype design is compromised by the presence of higher frequency internal resonances of the isolator, mitigation of which is the focus of ongoing work

Full text not available from this repository.

More information

Published date: 2014
Venue - Dates: 12th International Conference on Motion and Vibration Control (MoViC), Japan, 2014-01-01
Organisations: Dynamics Group

Identifiers

Local EPrints ID: 368072
URI: https://eprints.soton.ac.uk/id/eprint/368072
PURE UUID: 77cd8ec2-83ae-439b-8122-14e88641c818

Catalogue record

Date deposited: 15 Sep 2014 10:32
Last modified: 17 Jul 2019 20:52

Export record

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×