D4.3 - Determination of the dynamic iron content in magnetorheological fluids using an indirect measurement method based on an equivalent circuit model
- Event
- 22. GMA/ITG-Fachtagung Sensoren und Messsysteme 2024
2024-06-11 - 2024-06-12
Nürnberg - Band
- Vorträge
- Chapter
- D4 - Messdatenanalyse
- Author(s)
- T. Wiener, C. Offenzeller - STIWA Advanced Products GmbH,Gampern (Austria), B. Jakoby - Johannes Kepler University,Linz (Austria)
- Pages
- 368 - 373
- DOI
- 10.5162/sensoren2024/D4.3
- ISBN
- 978-3-910600-01-0
- Price
- free
Abstract
Magnetorheological (MR) fluids are a class of smart materials with versatile applications in various engineering domains. A MR fluid consists essentially of a carrier medium (e.g. synthetic oil) with embedded magnetizable particles (e.g., carbonyl iron particles in our case). The concentration of iron in the carrier medium determines the rheological properties of the MR fluid. The influence of the iron content in the MR fluid on the inductance of the system should be analyzed. The measurement technique investigated in our research relies on the analysis of current responses following a voltage step change which is applied to a coil magnetizing the MR under test in a test setup involving a magnetic circuit and a chamber containing the sample MR fluid. The evaluation process is conducted by means of utilizing a physically inspired model featuring lumped elements in an equivalent electrical circuit. This model is based on the T-equivalent circuit of a transformer incorporating representations of field induced eddy currents and particle motion within the MR fluid on the secondary side of the (fictitious) transformer. The model is then used to determine the inductance and to represent the electrical behavior of the actuator in a step response.