Print Email Facebook Twitter Governing Equation Identification of Nonlinear Single Degree-of-Freedom Oscillators With Coulomb Friction Using Explicit Stick and Slip Temporal Constraints Title Governing Equation Identification of Nonlinear Single Degree-of-Freedom Oscillators With Coulomb Friction Using Explicit Stick and Slip Temporal Constraints Author Mahajan, Saurabh (Student TU Delft) Cicirello, A. (TU Delft Mechanics and Physics of Structures) Date 2023 Abstract The friction force at joints of engineering structures is usually unknown and not directly identifiable. This contribution explores a procedure for obtaining the governing equation of motion and correctly identifying the unknown Coulomb friction force of a mass-springdashpot system. In particular, a single degree-of-freedom system is investigated both numerically and experimentally. The proposed procedure extends the state-of-the-art datadriven sparse identification of nonlinear dynamics (SINDy) algorithm by developing a methodology that explicitly imposes constraints encoding knowledge of the nonsmooth dynamics experienced during stick-slip phenomena. The proposed algorithm consists of three steps: (i) data segregation of mass-motion from mass-sticking during stick-slip response; (ii) application of SINDy on the mass-motion dataset to obtain the functional form of the governing equation; and (iii) applying sticking and slipping conditions to identify the unknown system parameters. It is shown that the proposed approach yields an improved estimate of the uncertain system parameters such as stiffness, viscous damping, and magnitude of friction force (all mass normalized) for various signal-to-noise ratios compared to SINDy. Subject Coulomb frictiondiscontinuous nonlinearityepistemic uncertaintynonlinear dynamic system identificationSINDystick and slip temporal constraints To reference this document use: http://resolver.tudelft.nl/uuid:a52a4c89-97b4-4c80-9376-d31823651424 DOI https://doi.org/10.1115/1.4063070 Embargo date 2024-02-25 ISSN 2332-9017 Source ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part B: Mechanical Engineering, 9 (4) Bibliographical note Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2023 Saurabh Mahajan, A. Cicirello Files PDF risk_009_04_041101.pdf 2.42 MB Close viewer /islandora/object/uuid:a52a4c89-97b4-4c80-9376-d31823651424/datastream/OBJ/view