Mateusz Romaszko

Experimental Tests of an Electromechanical Transducer of Reverse Linear Motion into Electrical Energy

This document deals with the results of laboratory tests of an experimental electromechanical transducer for supplying an magnetorheological (MR) damper. The aim of the tests was to determine: the electromotive force induced in the sectionalized coil, the voltage and the current strength in the control coil of the damper as well as instantaneous power. The results provided are based on the tests of the transducer under periodic kinematic excitations and are compared with those achieved in numerical calculations.

FEM Analysis of a Cantilever Sandwich Beam with MR Fluid Based on ANSYS

The study covers the modeling three-layered beam incorporating a magnetorheological (MR) fluid. The beam finite element model was created using the ANSYS software. The beam comprises two outer layers made of aluminium and MR fluid layer in between, sealed with silicone rubber. Interactions of the magnetic field are taken into account by varying the parameters of the finite elements. Data required for identification were collected from results of measurement of the beams free vibrations. The identification procedure assumes the good agreement between the frequencies of the beams free vibrations and dimensionless damping coefficients obtained from research and computation data. The validity of proposed beams finite element model was also investigated. Finally some numerical results were presented.

Identification of Complex Shear Modulus of MR Layer Placed in Three-Layer Beam – Part 2: Algorithm

The paper presents the procedure of identification of a complex shear modulus which describes properties of MR fluid in the pre-yield regime as a function of magnetic field. Data necessary for identification were collected basing on measurements of free vibrations of a three-layered cantilever beam at a special laboratory stand. Magnetic field exerting on MR fluid placed in the beam was generated by electromagnet. In the next step, complex modes of beam vibrations for various places of applying the magnetic field and its strength were calculated.

Identification of Complex Shear Modulus of MR Layer Placed in Three-Layer Beam – Part 1: Finite Element

The paper presents the finite element, which can be used to analyse the vibration of a three–layer beam with magnetorheological (MR) fluid layer. The MR fluid layer was sealed with silicone rubber. On the basis of the analysis of displacements, deformations of each layer has been established. Next, potential and kinetic energy of the three–layer beam were calculated. Because of the complexity of the beam with MR fluid, efficient solutions can be obtained only after discretization of the system. The finite element method was used in the study. For this purpose the mass and stiffness matrices were determined for the proposed linear finite element of two nodes and four degrees of freedom in each node.

Magnetic field analysis of the actuator in a semi-active vibration control of the beam with MR fluid

In this study the analysis of the magnetic field distribution of an electromagnet is presented. This electromagnet is used as an actuator in a semi-active vibration control of the three-layer beam with MR fluid. Two separate numerical methods are used for the purpose of calculating the magnetic field distribution. The first method is based on the Finite Element Method and implemented using ANSYS software. The second, simplified one is based on the assumption that the electromagnet can be substituted by a simple magnetic circuit divided into separate paths, with each sub-path defined by the value of reluctance of the corresponding electromagnet part. The comparison of the results from both methods with the ones obtained from an experiment is also presented and analyzed in the paper.