Soleimanian, Sina (2024) Semi-active Vibration Control for Vehicle Transmission Systems. [Tesi di dottorato]

Anteprima

Testo Soleimanian_Sina_36.pdf Download (7MB) | Anteprima

Abstract

This doctoral thesis proposes a novel semi-active vibration control technique for mechanical transmission systems. The backbone of current research technology is the adaptive stiffness and damping properties of metal rubber (MR) which plays the role of tuning to the vibrational system eigenmodes. The adaptive properties of MR material were proved by a previous study, but the present research investigates the effect of this feature on the structural response and designs an MR-based semi-active vibration controller for industrial application. For this purpose, the semi-active control strategy is created based on an optimal tuning using experimental harmonic test results. The control strategy is applied in practice using a linear actuator controlled by a double pole double throw (DPDT) relay, and National Instruments hardware and software for reading data and writing the control task. The isolator attachment position is defined through the analysis of eigen mode shapes that are predetermined by numerical simulation. The assessment of isolator effectiveness is carried out in two phases. The first phase investigates the vibration control rate for a cantilevered plate and the second phase studies a plate accommodating a bearing and a shaft. The last phase is dedicated to a plate accommodating bearing and shafts in a commercial vehicle transmission system. The first phase is prominent since it demonstrates the vibration isolator effect on dynamics response of a well-known structure. In the second phase, a maximum isolation rate of 55.17 % is measured near the vibration isolator position. It is observed that the isolation position has a prominent effect on structure vibration behavior where the elastic wave has been reduced in amplitude by passing the isolator position. The effectiveness of the MR-based semi-active control approach is eminent and its application for vibration isolation of commercial mechanical transmission systems could be studied in the future. In the third phase of study, a particular automotive transmission component—precisely, a plate dedicated to accommodating bearings—has been selected as the focus of research to control its noise and vibrations. A microcomputer-driven control system is applied, featuring characteristics such as high performance, compact size, lightweight design, and energy efficiency, which make it ideal for testing in the automotive sector. The efficacy of the devised control scheme is assessed through the deployment of accelerometers and sound intensity probes to quantify the vibrations and the radiated acoustic power, respectively. Interesting noise and vibration reduction rates are achieved using both open-loop and closed-loop strategies. This research opens the horizons to employ MR material in a semi-active configuration for industrial requirements surpassing its classical passive implementation, notably in terms of wide-band attenuation performance.

Downloads

Actions (login required)

Modifica documento