• Structural Engineering and Mechanics
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• v.63 no.2
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• pp.181-193
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• 2017

An identification method for determination of the parameters of the rheological models of dampers made of viscoelastic material is presented. The models have two, three or four parameters and the model equations of motion contain derivatives of the fractional order. The results of dynamical experiments are approximated using the trigonometric function in the first part of the procedure while the model parameters are determined as the solution to an appropriately defined optimization problem. The particle swarm optimization method is used to solve the optimization problem. The validity and effectiveness of the suggested identification method have been tested using artificial data and a set of real experimental data describing the dynamic behavior of damper and a fluid frequently used in dampers. The influence of a range of excitation frequencies used in experiments on results of identification is also discussed.

• Smart Structures and Systems
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• v.25 no.5
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• pp.581-592
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• 2020

Magneto-rheological fluids and magneto-strictive materials are of the well-known smart materials which are used to control and reduce the vibrations of the structures. Vibration analysis of a smart annular three-layered plate is provided in this work. MR fluids are used as the core's material type and the face sheets are made from MS materials and is assumed they are fully bonded to each other. The structure is rested on visco-Pasternak foundation and also is subjected to a transverse magnetic field. The governing motion equations are derived based on CPT and employing Hamilton's principle and are solved via GDQ as a numerical method for various boundary conditions. Effect of different parameters on the results are considered and discussed in detail. One of the salient features of this work is the consideration of MR fluids as the core, MS materials as the faces, and all of them under magnetic field. The outcomes of this study may be led to design and create smart structures such as sensors, actuators and also dampers.