Rate-dependent hysteresis: modeling, analysis and identification, with applications to magnetorheological dampers
Total activity: 34
Type of activity
MIN DE ECONOMIA Y COMPETITIVIDAD
Funding entity code
This project focuses on developing identification algorithms for systems with hysteresis of the "rate-dependent" type, the analysis of these systems, and on designing experiments with magnetorheological dampers to orient and validate the results. Hysteresis is a nonlinear phenomenon observed in some physical systems under low frequencies excitations. It can be classified into two categories: rate independent (RI) and rate dependent (RD). For RI hysteresis, the graph output versus input of the hysteresis system does not change with the frequency of the input signal. This is the case for example of the Bouc-Wen model, the Dahl model, or the Preisach model. For RD hysteresis, the graph output versus input of the hysteresis system may change with the frequency, and converges to a fixed loop (the hysteresis loop) when the frequency goes to zero. This is the case for example of the LuGre model and the semilinear Duhem model. Research in the field of hysteresis has focused mainly on the study of rate-independent hysteresis. It is only in the last 15 years that the importance of rate-dependent phenomena has been acknowledged. The way researchers dealt with this new challenge is by modifying existing rate-independent models of hysteresis to accomodate the rate-dependent features observed experimentally. However, up till very recently, there was no general framework to study rate-dependent hysteresis. Such framework has been developped by our group within the context of a previous DPI project. Our aim in the present project is to use this framework to explore rate-dependent hysteresis modeled by the LuGre and the semilinear Duhem model. The aforementioned models consist of nonlinear differential equations with unknown parameters. The determination of these unknowns from experimental data is called identification, and it is a problem of high interest for the scientific community. However, due to the fact that there exists not a general theory of identification for nonlinear systems, the identification of hysteresis models has mainly been done within an experimental framework where analytical issues were not the main target to achieve. One of the main objectives of this project is to fill this gap by developing identification algorithms for the mentioned classes of hysteresis systems, with analytical proofs of convergence of the estimated unknowns to their true counterparts. The experimental data used by the algorithms we intend to elaborate, are the periodic orbits (P. O.) obtained by exciting the hysteresis systems using periodic inputs. In our approach, to have a rigorous characterization of these P.O. is the key to construct an effective and robust identification algorithm. Finally, the identification methods we intend to develop are in open loop which implies that the process has to be stable. So the analysis of the stability of the mentioned class of nonlinear systems is utmost importance. The results of this project will be both driven and tested by means of numerical simulations and also by experiments that involve magnetorheological (MR) dampers. Additionally, we aim to use the framework of rate-dependent hysteresis developped by our group to provide experimental evidence of the behavior of minor loops of MR dampers (since this issue has been overlooked in the current literature for RD-hysteretic systems), and to study its implications in terms of the efficiency of this type of devices.
Puzzyrov, V.; Acho, L.; Pujol-Vazquez, G.; Rodellar, J. Journal of Theoretical and Applied Mechanics Vol. 57, num. 2, p. 519-531 DOI: 10.15632/jtam-pl/105471 Date of publication: 2019-04 Journal article