Coil springs with constrained-layer viscoelastic damping for passive isolation

Eric R. Ponslet; William O. Miller

doi:10.1117/12.310705

16 June 1998 Coil springs with constrained-layer viscoelastic damping for passive isolation

Eric R. Ponslet, William O. Miller

Proceedings Volume 3327, Smart Structures and Materials 1998: Passive Damping and Isolation; (1998) https://doi.org/10.1117/12.310705
Event: 5th Annual International Symposium on Smart Structures and Materials, 1998, San Diego, CA, United States

Abstract

This paper summarizes the design, optimization, development, fabrication, and testing of a vacuum compatible coil spring with embedded constrained layer visco-elastic damping. The spring is developed as part of the NSF funded LIGO (Laser Interferometer Gravity Wave Observatory) project. Large numbers of those springs are the primary components of multi- stage, in-vacuum, passive seismic isolation stacks that provide high attenuation (-160 dB/decade above 15 Hz) of floor vibrations for ultra-sensitive (better than 10^-18 m/(root)Hz noise floor between 40 and 1000 Hz) laser interferometers. The spring design addresses both requirements for passive isolation within a single, self- contained, vacuum tight envelope: low stiffness for maximum attenuation and non-viscous damping to limit resonant amplitudes in the stack. This is achieved with a tubular coil spring design with an internal torsional constrained layer damping structure. The paper presents the analysis of this spring using closed-form analytical expressions, trend studies showing the strong dependence of spring performance on key design parameters, and explicit numerical design optimization. Manufacturing issues are briefly discussed. Finally, experimental results from static and dynamic tests performed on prototype units are presented. Results show loss factors of the order of 1.5% in the transverse direction to 3% in the axial direction, at frequencies from 1 to 2 Hz.

Citation Download Citation

Eric R. Ponslet and William O. Miller "Coil springs with constrained-layer viscoelastic damping for passive isolation", Proc. SPIE 3327, Smart Structures and Materials 1998: Passive Damping and Isolation, (16 June 1998); https://doi.org/10.1117/12.310705

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available