Papers by Author: Bogdan Sapiński

Abstract: This paper summarises the results of numerical calculations of magnetic field and circuit parameters in an electromagnetic generator supplying a rotary MR damper. The design and operating principles of the generator are outlined. The distribution of the magnetic flux density vector is obtained, other parameters include its modulus, the magnetic flux from permanent magnets and time patterns of induced voltage and current in the control coil of the damper, power and energy of magnetic field in this coil at different rotational speeds of the induction with respect to the armature.

Abstract: The paper presents the conditioning system prototype intended for an electromagnetic generator supporting an MR damper in self-powered vibration reduction systems. The system engineered in the form of an electronic circuit comprises the following blocks: the MR damper control coil supply, self-powering, measurement and the microcontroller. The self-powering function consists in supplying the microcontroller from the generator, assuming that the voltage is larger than that required to power the microcontroller, otherwise the microcontroller will take up energy from a battery since the system has also the battery charging option. The performance of the system was verified through experiments where it acted as a component of a vibration reduction system.

Abstract: Magnetic Shape Memory Alloys (MSMA) constitute one of the newest groups of intelligent materials [. Although these materials have yet to find commercial applications, literature with information on the first pre-prototype actuators can already be found. The mechanism of operation of these actuators is based on the magnetic shape memory effect. During tests, the shifting of piston and current in the coil of the electromagnet were measured. Measurements were synchronized with set courses of this current coil of the actuator. The obtained results made it possible to make static characteristics for constant levels of current, and dynamic curves for constant values of frequency as well as to construct a mathematical model. In this work, the authors have described laboratory tests of an experimental actuator of this type.

Abstract: Recent advances in the research of magnetorheological (MR) fluid based devices have indicated the opportunities for squeeze mode devices using the smart fluids. The mode seems suitable for small amplitude and high force applications. Therefore, it is of a research and engineering interest to explore the model of a controlled squeeze mode MR mount (damper). As such, in the paper the authors highlight the model of a squeeze mode hydraulic mount, then present the simulation results in the form of dynamic stiffness and damping vs. frequency plots, respectively.

Abstract: This paper is devoted to modeling of a three-layered cantilever beam filled with magnetorheological (MR) fluid. The beam consists of two aluminium outer layers and an MR fluid layer placed between them. The study covers description of MR fluid behavior in the pre-yield regime, analysis of strain and internal forces, formulation of differential equations of motion and finite element model (FEM) and numerical calculations. The aim of the study is to determine maximal amplitudes up to which the MR fluid operates in the pre-yield regime.

Abstract: The study is devoted to the electromagnetic induction device (EID) attached to the magnetorheological (MR) damper. The study covers design considerations, calculations of magnetic field, fabrication and testing of the EID on the dynamic testing machine (DTM).