Criteria For Comparing The Effectiveness Of Damping Treatments
Report Number: WADD TR 61-25
Author(s): Mead, D. J.
Corporate Author(s): University Of Southampton
Laboratory: Materials Central
Date of Publication: 1961-01
Pages: 46
Contract: AF 61(052)-332
DoD Project: 7351 - Metallic Materials
DoD Task: 73521
Identifier: AD0408982
Abstract:
In this report, expressions are derived for the response of simple vibrating systems, from which criteria have been deducted to indicate the effectiveness of a damping treatment in attenuating the response. The criteria include factors by which the treatment increases the mass and stiffness of the system, together with the loss factor increment. The response quantities considered include bending stresses, accelerations, inertis forces and sound transmission associated with simple vibrating plates under harmonic and random excitation. Coincidence sound transmission is also briefly considered. It is shown that whereas the mass and loss factor increase is always advantageous, a stiffness increase in some instance is detrimental. As an example, three different commercial treatments are compared on the basis of some of the criteria. With low treatment weights, the treatment providing the highest loss factor is superior judged by each criterion, but at higher weights according to some criteria a treatment having a lower stiffness, density and loss factor is more effective. The existence of optimum treatment weights for maxiumum effect upon the response is also shown by some criteria.
Provenance: IIT
Author(s): Mead, D. J.
Corporate Author(s): University Of Southampton
Laboratory: Materials Central
Date of Publication: 1961-01
Pages: 46
Contract: AF 61(052)-332
DoD Project: 7351 - Metallic Materials
DoD Task: 73521
Identifier: AD0408982
Abstract:
In this report, expressions are derived for the response of simple vibrating systems, from which criteria have been deducted to indicate the effectiveness of a damping treatment in attenuating the response. The criteria include factors by which the treatment increases the mass and stiffness of the system, together with the loss factor increment. The response quantities considered include bending stresses, accelerations, inertis forces and sound transmission associated with simple vibrating plates under harmonic and random excitation. Coincidence sound transmission is also briefly considered. It is shown that whereas the mass and loss factor increase is always advantageous, a stiffness increase in some instance is detrimental. As an example, three different commercial treatments are compared on the basis of some of the criteria. With low treatment weights, the treatment providing the highest loss factor is superior judged by each criterion, but at higher weights according to some criteria a treatment having a lower stiffness, density and loss factor is more effective. The existence of optimum treatment weights for maxiumum effect upon the response is also shown by some criteria.
Provenance: IIT