A new compact model of squeeze-film damping is developed based on the numerical solution of the Boltzmann kinetic equation. It provides a simple expression for the damping coefficient and the quality factor valid through the slip, transitional and free-molecular regimes. In this work, we have applied statistical analysis to the current model using the chi-squared test. The damping predictions a...

The paper describes an investigation of the effect of structural damping in the torsion mode on wing flutter with the object of finding circumstances in which damping reduces the flutter speed. The drop in flutter speed can be considerable (25 per cent) and extend to very large values of structural damping. The effect is most apparent when the relative density (wing to air) is high, and when th...

a reliability analysis of suspension bridges against buffeting failure due to gustiness of wind velocity is carried out using the concept of pra (probabilistic risk analysis) procedure. for this purpose, the bending stresses at the critical nodes of the bridge deck are obtained for buffeting forces using a spectral analysis technique and a finite element approach. for the purpose of reliability...

Noise, Vibration and Harshness (NVH) is a critical consideration in the design of automotive and aerospace vehicles for comfort, and fatigue of components arising from interior structural and acoustic pressure fluctuations due to external structural or acoustic loading. In the low to mid frequency range, current NVH models, obtained by direct, unsymmetric, coupled Eulerian Finite Element discre...

this study is investigated the optimum parameters for a tuned mass damper (tmd) under the seismic excitation. shuffled complex evolution (sce) is a meta-heuristic optimization method which is used to find the optimum damping and tuning frequency ratio for a tmd. the efficiency of the tmd is evaluated by decreasing the structural displacement dynamic magnification factor (ddmf) and acceleration ...

We consider a mechanical system excited by an external force. Model of such a system is described by the system of ordinary differential equations: Mẍ(t) + D(v)ẋ(t) + Kx(t) = f̂(t), where matrices M,K (mass and stiffness) are positive definite and the vector f̂ corresponds to an external force. The damping matrix D(v) is a positive semidefinite matrix which depends on damping positions and parame...