<abstract xmlns="http://www.w3.org/1999/xhtml"><p>The purpose of this paper is to investigate a double torsion pendulum with planar frictional contact. The single torsion pendulum with one-degree-of-freedom is an angular equivalent of the linear harmonic oscillator. The second degree of freedom has been obtained by adding a free body to the inverted single torsion pendulum. The free body’s angular displacement is caused by frictional forces appearing in the interface (contact zone) between the free body and the pendulum column’s head kinematically excited at its base by a mechanism with torsion spiral spring. An experimental station has been set up and run to find most unknown parameters of the pendulum from the time series of state variables taken as inputs to the Nelder-Mead method of identification. The obtained results proved significant usability of the identification method in the case of numerical simulation of the pendulum’s dynamical model. It has not been satisfactorily proved in the case of time characteristics coming from a real system that exhibits also some unrecognized physical effects.</p></abstract>

The purpose of this paper is to investigate a double torsion pendulum with planar frictional contact. The single torsion pendulum with one-degree-of-freedom is an angular equivalent of the linear harmonic oscillator. The second degree of freedom has been obtained by adding a free body to the inverted single torsion pendulum. The free body’s angular displacement is caused by frictional forces appearing in the interface (contact zone) between the free body and the pendulum column’s head kinematically excited at its base by a mechanism with torsion spiral spring. An experimental station has been set up and run to find most unknown parameters of the pendulum from the time series of state variables taken as inputs to the Nelder-Mead method of identification. The obtained results proved significant usability of the identification method in the case of numerical simulation of the pendulum’s dynamical model. It has not been satisfactorily proved in the case of time characteristics coming from a real system that exhibits also some unrecognized physical effects.

Modeling And Parameter Identification Of Vibrations Of A Double Torsion Pendulum With Friction

Department of Automation, Biomechanics and Mechatronics, Lodz University of Technology, ul. Stefanowskiego 1/15, 90-924 Łódź, Poland

Acta Mechanica et Automatica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The purpose of this paper is to investigate a double torsion pendulum with planar frictional contact. The single torsion pendulum with one-degree-of-freedom is...

Modeling And Parameter Identification Of Vibrations Of A Double Torsion Pendulum With Friction

Published Online: Dec 30, 2015

Page range: 204 - 212

Received: Aug 23, 2015

Accepted: Dec 10, 2015

DOI: https://doi.org/10.1515/ama-2015-0033

Keywords
Friction, Planar Contact, Numerical Modeling, Double Torsion Pendulum, Parameter Identification, Nonlinear Vibrations, Kinematic Excitation, Kinematic Forcing Mechanism, Nelder-Mead Method

© 2015 Bialystok University of Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Modeling And Parameter Identification Of Vibrations Of A Double Torsion Pendulum With Friction

Published Online: Dec 30, 2015

Page range: 204 - 212

Received: Aug 23, 2015

Accepted: Dec 10, 2015

DOI: https://doi.org/10.1515/ama-2015-0033

KeywordsFriction, Planar Contact, Numerical Modeling, Double Torsion Pendulum, Parameter Identification, Nonlinear Vibrations, Kinematic Excitation, Kinematic Forcing Mechanism, Nelder-Mead Method

© 2015 Bialystok University of Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
Friction, Planar Contact, Numerical Modeling, Double Torsion Pendulum, Parameter Identification, Nonlinear Vibrations, Kinematic Excitation, Kinematic Forcing Mechanism, Nelder-Mead Method