Showing papers on "Loss factor published in 1985"
TL;DR: In this paper, it is shown that in the case of the standing wave resonance method, the use of the simple classical frequency equation for the determination of the complex modulus of a viscoelastic prismatic element from the modal values of frequency and transmissibility results in an absolute error of less than 8% for loss factors of up to 0·4.
48 citations
TL;DR: In this article, the optimum thickness distribution of unconstrained viscoelastic damping layer treatments for plates was investigated. And the results indicated that the system loss factor can be increased by as much as 100%, or more, by optimizing the thickness distribution.
30 citations
01 May 1985
TL;DR: In this paper, a finite element procedure is described for calculating the loss factors for elastic structures to which frequency-dependent viscoelastic damping treatments were applied, and the loss factor is computed by the modal strain energy (MSE) approach.
Abstract: A finite element procedure is described for calculating the loss factors for elastic structures to which frequency-dependent viscoelastic damping treatments were applied. The frequency dependence of the viscoelastic damping material is treated by approximating its shear modulus with a second-order polynomial so that the stiffnesses associated with the constant, linear, and quadratic terms can be combined, respectively, with the stiffness, damping, and mass matrices assembled for the rest of the structure. A single complex eigenvalue analysis is then performed in which the eigenvalues are purely imaginary. The loss factor is computed by the modal strain energy (MSE) approach. In the the MSE approach, the loss factor of a composite structure vibrating in one of its natural modes may be visualized as a weighted average of the loss factors of the component parts, with the relative stored energies as weighting constants. The finite element procedure, which can treat very general geometries, is illustrated for the case of a vibrating constrained-layer damped plate.
2 citations