Modal dynamic instabilities generated by frictional contacts. - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2013

Modal dynamic instabilities generated by frictional contacts.

Résumé

In mechanical systems the frictional forces at the contact interfaces allow for coupling the system dynamics and the contact behavior, originating dynamic instabilities. From a numerical point of view the contact forces introduce an asymmetry on the system stiffness matrix, acting as a cross coupling factor between tangential and normal motion to the contact interface. Typical examples of this phenomenon, largely investigated in literature, are the squeal noise emission in automotive brakes or railway wheels. A general analysis is here proposed, showing how the deformation modes of a single deformable body can be excited by the frictional forces and become unstable. In this study the behaviour of a simple mechanical system is numerically analyzed. The system is composed by a polycarbonate cylinder constrained on the external surface and a steal cylinder rotating inside the first one. The inner cylinder is expanded to assure the contact pressure between the two bodies. The simplicity of the system considered allows for reducing the problem to a 2D model and the difference in stiffness between the two materials allows for considering only the polycarbonate body as deformable for the transient simulation. Two different approaches are used: a linear complex eigenvalue analysis (CEA) and a nonlinear transient analysis. The results obtained on a single deformable solid in frictional contact allow for generalizing the findings obtained in recent literature dealing with brake squeal, i.e. the lock-in instability, to a general frictional system. The selection mechanism between the unstable modes predicted by the linear CEA is investigated. An experimental validation is presented.
Fichier non déposé

Dates et versions

hal-00872518 , version 1 (13-10-2013)

Identifiants

  • HAL Id : hal-00872518 , version 1

Citer

Jacopo Brunetti, Francesco Massi, Aurélien Saulot, Walter d'Ambrogio. Modal dynamic instabilities generated by frictional contacts.. 5° World Tribology Congress, Sep 2013, Torino, Italy. ⟨hal-00872518⟩
128 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More