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Published on: September 28, 2015
Shear response of a frictional interface to a normal load modulation
1Groupe de Physique des Solides, 2 place Jussieu, 75251 Paris Cedex 05, France.
Summary
Modulating normal load on sliding interfaces significantly reduces friction. An elastoplastic friction model, incorporating both plastic junction response and elastic asperity deformation, accurately predicts this behavior at high frequencies.
Area of Science:
- Tribology
- Materials Science
- Physics of Interfaces
Background:
- Sliding interfaces under normal load exhibit complex friction dynamics.
- Existing friction models like Rice-Ruina are effective for slow dynamics but may not capture high-frequency responses.
Purpose of the Study:
- To investigate the shear response of a sliding multicontact interface under harmonically modulated normal load.
- To develop and validate an extended friction model for high-frequency regimes.
Main Methods:
- Experimental measurement of friction force (average, first and second harmonic components) at low velocities (V<100 μm s⁻¹).
- Application of a harmonically modulated normal load at a frequency (120 Hz) much higher than the interface's natural frequency.
- Development of an elastoplastic friction model incorporating plastic junction response and elastic asperity deformation.
Main Results:
- A substantial decrease in average friction force (&Fmacr;) was observed with modest normal load modulation.
- The Rice-Ruina model required extension to accurately describe the high-frequency frictional response.
- The proposed elastoplastic friction model demonstrated excellent quantitative agreement with experimental data.
Conclusions:
- Normal load modulation is an effective method to reduce friction in sliding interfaces.
- An elastoplastic friction model is necessary to accurately capture the shear response at high frequencies.
- The study provides a validated model for understanding and predicting friction in dynamic loading scenarios.
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