Ice-rubber friction mechanisms across scales

Area of Science:

• Tribology
• Materials Science
• Polymer Physics

Background:

• Rubber-ice friction is critical for vehicle safety and performance.
• Understanding friction mechanisms requires bridging macroscopic and molecular scales.
• Existing models often fail to capture the complex interplay of adhesion and thermal effects.

Purpose of the Study:

• To investigate the multiscale friction mechanisms between SBR-silica elastomers and ice.
• To develop a predictive model for rubber-ice interfacial shear stress.
• To identify distinct friction regimes based on sliding velocity and temperature.

Main Methods:

• Simultaneous measurement of force and real contact area during sliding.
• Experimental testing across a range of velocities (50 µm s^-1-1 m s^-1) and temperatures (down to -30 °C).
• Analytical modeling incorporating viscoelastic adhesion, interfacial heating, and molecular kinetics (Chernyak-Leonov).

Main Results:

• Identified three friction regimes: adhesion/dissipation-dominated, heat generation-dominated, and thermally-driven/melting-influenced.
• Observed a non-monotonic velocity dependence of the real contact area and a bell-shaped shear stress-velocity curve.
• Developed a dimensionless average contact temperature that normalized data across conditions.
• Validated a multiscale model predicting interfacial shear stress based on experimental data.

Conclusions:

• Rubber-ice friction is governed by coupled viscoelastic and thermal phenomena across multiple scales.
• The developed multiscale model provides accurate predictions of friction behavior.
• Understanding these mechanisms is key for designing advanced tire materials and improving winter traction.