On discontinuous dynamics of a SDOF nonlinear friction impact oscillator

Autor: Min Gao, Chenjing Dou, Jinjun Fan, Shoulian Chen, Jing Cao
Rok vydání: 2020
Předmět:
Zdroj: International Journal of Non-Linear Mechanics. 121:103457
ISSN: 0020-7462
DOI: 10.1016/j.ijnonlinmec.2020.103457
Popis: In this paper, the discontinuous dynamical behaviors of a SDOF nonlinear oscillator in the co-existence of friction and impact are studied via using flow switchability theory of discontinuous dynamical systems, where considering that the static friction coefficient is greater than the kinetic friction coefficient at the object’s velocity tending to zero and the friction coefficient is described by the Stribeck friction model. Because of both friction and collision, the object will have four motion states: free motion, impacting motion, stationary state (or stick motion) and stuck motion. According to discontinuity caused by the abrupt change of friction force and the constraint of the right rigid wall, the phase space is divided into various domains and boundaries. Due to the particularity of friction force, the flow barrier on the segmentation boundary is considered, which may affect the leaving flow at the velocity boundary. The analytical conditions for all possible motions are acquired through G-functions on the corresponding boundaries based on the analysis of vector fields in domains. The mapping structures are introduced and the periodic motions of this system are presented by the basic mappings. In order to understand the motion conversion principium of the SDOF oscillator more intuitively, the time histories of displacement, velocity, G-functions and the corresponding trajectories in phase plane for the object are shown by simulation numerically. Finally, the grazing and stick bifurcation scenarios for excitation frequency and excitation amplitude are presented.
Databáze: OpenAIRE
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