This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
A Review of Theories on Constrained Layer Damping and Some Verification Measurements on Shim Material
Technical Paper
2003-01-3321
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Introducing a rubbercoated steel plate - a shim - on the backing plate of a brake pad often solves squeal problems in disc brakes. This may be attributed to one or more of several effects exerted by the shim:
- Isolation or decoupling of brake components
- Alteration of the force configuration
- The addition of damping
The effect of damping may be active in either or both of the following ways:
- In the direction of the normal force exerted by the piston
- As a constrained layer damping of the bending vibration of the pad
This paper will deal with the constrained layer damping effect introduced by applying a viscoelastic material and an additional steel plate on top of the backing plate. This paper reviews some theories on constrained layer damping and extracts information on the effect of varying important parameters such as layer thickness, stiffness of the constrained material etc. Measurements on specially designed damping materials are performed in order to verify the predictions of the theories, and finally measurements on a commercial available shims material are presented. The measurements are made with the conventional ‘half power bandwidth method’ on a specially designed plate that behaves like a beam in the frequency range of interest. The theory on constrained layer damping predicts important properties that are relevant for the application of shims material and the measurements shows a qualitative agreement with the predictions.
Recommended Content
Topic
Citation
Flint, J., "A Review of Theories on Constrained Layer Damping and Some Verification Measurements on Shim Material," SAE Technical Paper 2003-01-3321, 2003, https://doi.org/10.4271/2003-01-3321.Also In
References
- Flint J. Disc Brake Squeal University of Southern Denmark 2002
- Oberst H. Über die dämpfung der biegeschwingungen dünner bleche durch fest haftende belage Akustische Beihefte, Acustica 4 181 194 1952
- Kerwin E.M. Damping of flexural waves by a constrained viscoelastic layer JASA 31 952 962 1959
- DiTaranto R.A. Theory of vibratory bending for elastic and viscoelastic layered finite-length beams Journal of Applied Mechanics 87 881 886 1965
- Mead D.J. Markus S. The forced vibration of three-layer, damped sandwich beam with arbitrary boundary conditions Journal of Sound and Vibration 10 2 163 175 1969
- Yan M.-J. Dowell E.H. Governing equations for vibrating constrained-layer damping sandwich plates and beams Journal of Applied Mechanics 94 1041 1046 1972
- Cremer L. Heckl M. Ungar E.E. Structure-Borne Sound Springer Verlag Berlin 1988
- Ewins D. J. Modal Testing: Theory and Practice Roberts J. B. Dr. University of Sussex England 1986