This paper presents the Fourier and wavelet characterization of vibratio...

A particle impact damper (PID) dissipates the vibration energy of a structure through impacts within damper. The PID is not commonly used in practice mainly because its low damping-to-mass ratio and difficulty achieving optimal design due to nonlinear characteristics. In contrast, Coulomb friction (FD) can offer higher damping force-to-mass than other dampers, but it also difficult be controlle...

considerations on the explosion resistant design of special infrastructures have increased in the recent years. amongst the various types of infrastructures, road and railway tunnels have a unique importance due to their vital role in connection routes in emergency conditions. in this study, the explosion effects of a projectile impacting on a railway tunnel located in a jointed rock medium has...

A new approach is developed for finite element modeling of muiti-layer laminated beams. Within the beam element, the laminate is decomposed as muttiple basic layers, such as base beam layers of metal like, soft-core layers of adhesives, and soft coating layers of polymers, and mass and stiffness matrices of these basic layers are assembled together to generate those matrices for the beam elemen...

Dynamic properties of the soils at the Lotung test site, Lotung, Taiwan, are estimated from seismic vertical array measurements (input± output data sets) using both time-invariant and time-variant parametric modeling methods (system identi®cation). Soil properties are directly mapped from model parameters to an equivalent lumped mass model of the soil interval. Shear stiffness and damping ratio...

In this paper, a new viscoelastic size-depended model developed based on a modified couple stress theory and the for nonlinear viscoelastic material in order to vibration analysis of a viscoelastic nanoplate. The material of the nanoplate is assumed to obey the Leaderman nonlinear constitutive relation and the von Kármán plate theory is employed to model the system. The viscous parts of the clas...

A = aerodynamic stiffness matrix C = speed of sound E = complex Fourier matrix f , F = physical and modal forces h = height of stream tube j = imaginary unit K, M = stiffness and mass matrices NB = number of blades P, Q = modal transformation matrices p = flow pressure Q = flow mass flux at the boundary q = generalized (modal) coordinate s = distance along the boundary T = period of flow unstea...

Joshi, Aditi S. M.S.M.E., Purdue University, May 2014. Study of Aluminum Honeycomb Sandwich Composite Structure for Increased Specific Damping. Major Professors: Dr. Douglas E. Adams and Dr. J. Stuart Bolton, School of Mechanical Engineering The aluminum honeycomb sandwich composite structure is commonly used in the aerospace and automotive applications where high strength to weight ratio is de...