The topology optimization design of structures with anisotropic constrained damping layers (ACDL) is investigated in present paper. The evolutionary structural optimization (ESO) method is employed to find the optimal layout of ACDL with aim to maximum the modal damping loss factor of the sandwich structure. Modal strain energy (MSE) method is used to calculate the damping loss factor of whole ...

It has been observed that even though modal frequencies are well estimated using Operational Modal Analysis (OMA) techniques, damping estimation is not as accurate. The opinions on this aspect of OMA have been widely varying and no consensus or definite answers are available. In this paper the OMA procedure, data processing and modal parameter estimation, is studied with respect to proper dampi...

identification of damping parameter is usually more complicated and unreliable comparing to mass or stiffness identification in structural dynamics. there are many factors such as intermolecular friction, coulomb friction and viscous damping affecting the damping mechanisms in a structure. therefore it is difficult, and in some cases impossible, to describe the details of damping mechanisms by ...

local site conditions have a strong effect on ground response during earthquakes. two important soil parameters that control the amplification effects of seismic motions by a soil column are the soil hysteretic damping ratio and shear wave velocity. this paper presents the results of in situ damping ratio measurements performed using continuous surface wave attenuation data at a site in semnan ...

A wave model is proposed for estimating damping loss factor as a function of frequency for a beam with arbitrary transient loading applied through the boundary conditions. In contrast to modal methods which provide measures of damping only at the modal frequencies of the test structure, the damping factor is determined over discrete, but regularly spaced, frequency values associated with the te...

The resonant frequency and sensitivity of an atomic force microscope (AFM) cantilever with assembled cantilever probe (ACP) have been analyzed and a closed-form expression for the sensitivity of vibration modes has been obtained. The proposed ACP comprises an inclined cantilever and extension, and a tip located at the free end of the extension, which makes the AFM capable of topography at sidew...

L. Dahil, Istanbul Arel University, Department of Mechanical and Metal Technologies, Turkey, A. Karabulut, Afyon Kocatepe University, Faculty of Technology, MechanicalEngineering, Turkey, S. Baspınar, Afyon Kocatepe University, Technical EducationFaculty, Turkey In this study,damping ratios of 3 samples made of aluminum foam material, which have diff erent-density pores, were calculated, the ef...

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...

We present a model reduction Lanczos method for the computation of frequency response functions of Rayleigh damping problems. The connection with modal extraction and modal superposition is made. The usual model reduction methods require complex arithmetic. With the proposed method, complex arithmetic is only used for the reduced problem. A numerical example from structural damping is given.

A procedure is presented for modal and damping synthesis of flexible space structures from subsystem tests and/or analyses. In view of the various damping mechanism operative in a space structure, their contribution to total system damping and its compatibility with dynamic testing procedures, the spacecraft subsystems are identified as joints and components. The dynamics of joint subsystems is...