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Parameter identification of Bouc-Wen model for vacuum packed particles based on genetic algorithm

Bartkowski Piotr, Zalewski Robert, Chodkiewicz Paweł

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 2

322--333

EN

This paper investigates cylindrical samples made of vacuum packed particles. Such structures are composed of granular media placed in a hermetic encapsulation where, in the final stage, a partial vacuum is generated. The main advantage of such a structure is that the underpressure value makes it possible to control the global physical properties of granular systems. Materials with various grains are analyzed in the paper. A modified Bouc-Wen hysteresis model is adopted to describe the nonlinear properties of the tested specimens. To identify the model parameters, a genetic algorithm is applied. The proposed model is found to be in good agreement with the experimental data.

2

Performance comparison of active and semi-active SMC and LQR regulators in a quarter-car model

Ferdek U., Łuczko J.

Journal of Theoretical and Applied Mechanics

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2015

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Vol. 53 nr 4

811—822

EN

In this paper, an analysis is performed on a quarter-car model of car suspension with semi- -active and active damper utilizing the sliding mode (SMC) and linear-quadratic control (LQR). The effect of control parameters and time delays in the transmission of control signal on the factors related to the safety and comfort of driving is investigated. The results obtained from numerical simulations are shown in form of frequency characteristics for several selected performance factors.

3

Semi-active suboptimal control strategy applied to periodically vibrating mechanical systems

Miachajłow M., Szolc T.

IPPT Reports on Fundamental Technological Research

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2013

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nr 4

31--36

EN

The aim of this paper is to present the new method for obtaining the semi-active suboptimal control strategy, used for the purpose of vibration reduction in mechanical systems. The method is dedicated to systems where vibrations are of a periodic type. Generally, many semi-active control strategies have been developed up to date, but it seems that none of them are applied directly to the problem of mechanical systems suffering from disadvantageous, periodical vibrations. Probably, the reason why there were no such attempts in the past is that the semi-active vibration damping methods most often were used in situations where systems experience a finite time transient excitation, like for example seismic activity. In a case of systems experiencing repeatable (periodic), steady-state vibrations, such as machines or vehicles working at their nominal conditions, the common approach was to use the passive methods rather than the semi-active ones. This situation is changing nowadays and attempts of using semi-active methods to attenuate the disadvantageous steady state vibrations in machines and vehicles are becoming more common and successful. Therefore, there has been observed a surge in developing of the general purpose methods for determination of the optimal control strategies for such applications. The described method aspires to be the one of possible alternatives.

4

A Design of piezoelectric vibration absorber with the capacitive adjustment

Pietrzakowski M.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2002

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Vol. 6, No 3

363-369

EN

In the paper the problem of vibration damping via piezoelectric absorbers capacitively shunted is studied. The considered system is a simply supported beam with the absorber composed of piezoceramic patches joined by means of brackets in a uniform distance from the beam surface symmetrically on both sides of the beam. Due to the applied damping strategy piezoceramic actuators are shunted with a changeable capacitor in the external circuit to tune the resonance frequencies of the system. The analysis is completed with results of numerical simulations.