VІ-13 20 th INTERNATIONAL SCIENTIFIC CONFERENCE “TRANSPORT 2011” CALCULATION OF BANDWIDTH OF A TRANSDUCER FOR LATERAL FORCE ACTING IN WHEELSETS OF RAILWAY VEHICLES Nebojša Bogojević, Snežana Ćirić Kostić, Aleksandar Vranić, Zlatan Šoškić bogojevic.n@mfkv.kg.ac.rs Faculty of Mech. Engineering Kraljevo, University of Kragujevac, Dositejeva 19, Kraljevo Serbia Abstract: The aim of this paper is to estimate the bandwidth of the KUB transducer for measurement of the lateral forces that act upon the wheelset of rail vehicle. The solid 3D model of the transducer's body has been created and the natural frequencies of the transducer's body have been calculated by FEM analysis. The results obtained from modal analysis that enable estimation of the bandwidth of the KUB transducer are compared to the UIC recommendations in order to establish applicability of KUB transducer for the application in investigation of railway vehicles. Key words: transducer, bandwidth, wheelset, rail vehicle INTRODUCTION Bandwidth of a transducer is the main descriptor of its dynamic properties. It represents the frequency range in which amplitude-frequency characteristic of the transducer is constant, and phase- frequency characteristic of the transducer is linear. If frequency spectrum of an input signal belongs to the bandwidth of a transducer, then the corresponding output signal is proportional to the input signal, i.e. a transducer does not distort input signals with frequency spectra within the bandwidth of the transducer. Therefore, the bandwidth of a transducer determines input signals that may be processed by application of the transducer. International regulations [1] for investigations of safety and comfort of railway vehicles demand that measurements of mechanical quantities during test rides should be performed with frequency of acquisition that has to be higher than 200 Hz. Besides mechanical quantities that may be measured by commercial measurement transducers (acceleration), these regulations request measurements of mechanical quantities that are to be measured by specialized devices, like it is the case with the lateral force which acts on wheelsets of investigated railway vehicle (the force will be denoted as H-force in the text that follows). This paper presents estimation of the bandwidth of a transducer for measurement of H-force by numerical methods. The goal of the investigation is to determine if the transducer satisfies requirements for measurements of the horizontal forces that act on the wheelset of the rail vehicle. Mechanics ISSN 1312-3823 Transport issue 3, 2011 Communications article № 0576 Academic journal http://www.mtc-aj.com