Abstract Viscoelastic damping material has been widely used in engineering machinery to absorb vibration and noise. Dynamic behavior of the viscoelastic is mainly affected by temperature frequency. Classical dynamic equations have complex structures with multiple ambiguous parameters. So a novel variable-order fractional constitutive model (VOFC) established based on operator. Then are derived ...

Due to the medium and small damping characteristics of the hard coating compared with viscoelastic materials, the classical modal strain energy (CMSE) method cannot be applied to the prediction of damping characteristics of hard-coating composite structure directly. In this study, the CMSE method was modified in order to be suitable for this calculation, and then the damping optimization of the...

The internal friction of high-purity NiAl single crystals was investigated utilizing a low-frequency subresonance torsion a p m . Above lOOOK the damping increases strongly up to Q-' =0.3 at 1400K. The activation enthalpy of this viscoelastic relaxation depends on the composition and shows the highest value (2.8eV) for stoichiometric NiAl. The results are discussed in terms of diffusionantrolle...

1. Abstract An efficient damping layout optimization method of structural-acoustic systems is proposed to minimize acoustic responses using a gradient-based optimization algorithm. To analyze vibro-acoustic systems, a hybrid model that uses finite elements for the structures and boundary element for the cavity is developed. The four-parameter fractional derivative model is used to represent the...

Abstract Viscoelastic materials is a kind of damping which has been wildly applied in vibration control ocean and civil engineering, viscoelastic mostly work complex thermoelectric multi-field coupled environment. In this work, two-dimensional plate studied with stain relaxation time time. The placed magnetic field, the upper surface subjected to thermal shock. problem investigated by modified ...

In a previous paper (Hilton & Yi 1992), a systematic study was undertaken to determine how shapes of relaxation–time functions affect damping characteristics of isotropic viscoelastic materials. The significant parameters were the instantaneous and fully relaxed moduli (Regions A and E on Fig. 1), the two “knees” (B and D), the central slope (C) and anisotropic shift functions. The sensitivity ...

Amorphous polymers have been extensively used for energy dissipative applications due to their relatively low density and controllable rate dependent damping. In general, molecular mobility depends on the rate of applied loading and the ambient temperature, and results in a wide variety of mechanical properties. The variation in the macromolecular chain dynamics can be obtained by altering the ...

In this article we show exponential and polynomial decay rates for the partially viscoelastic nonlinear wave equation subject to a nonlinear and localized frictional damping. The equation that model this problem is given by utt − κ0∆u + ∫ t 0 div[a(x)g(t− s)∇u(s)] ds + f(u) + b(x)h(ut) = 0 in Ω× R, (0.1) where a, b are nonnegative functions, a ∈ C(Ω), b ∈ L∞(Ω), satisfying the assumption a(x) +...

Abstract In this article, we consider a viscoelastic plate equation with past history, nonlinear damping, and logarithmic nonlinearity. We prove explicit general decay rate results of the solution to history. Convex properties, inequalities, generalized Young’s inequality are mainly used estimate.

Behavior of a poro-elastic material bonded onto a vibrating plate is investigated in the low-frequency range. From the analysis of dissipation mechanisms, a model accounting for damping added by the porous layer on the plate is derived. This analysis is based on a 3-D finite element formulation including poroelastic elements based on Biot displacement theory. First, dissipated powers related to...