How Can I Effectively Model And Simulate The Effects Of Thermal Fade On A Carbon-carbon Brake Disc's Friction Coefficient And Wear Characteristics During Repeated High-speed Braking Events, Taking Into Account The Disc's Micro-structural Changes And The Interaction With The Brake Pad's Kevlar Fibers?

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To effectively model and simulate the effects of thermal fade on a carbon-carbon brake disc's friction coefficient and wear characteristics during repeated high-speed braking events, follow this organized approach:

1. Literature Review and Material Understanding

  • Objective: Gather existing models and material properties for carbon-carbon composites and Kevlar.
  • Actions: Review studies on tribological properties, thermal degradation, and friction models.

2. Thermal Modeling

  • Tool: Use Finite Element Analysis (FEA) tools like ANSYS or ABAQUS.
  • Parameters: Incorporate thermal conductivity, specific heat capacity, and density of materials.
  • Boundary Conditions: Include heat generation from friction, convection, radiation, and conduction.

3. Mechanical Modeling

  • Friction Model: Implement a temperature-dependent Coulomb friction model.
  • Wear Model: Apply Archard's wear law, considering temperature and contact pressure variations.

4. Material Degradation

  • Micro-structural Changes: Model degradation of carbon-carbon matrix and Kevlar fibers under heat.
  • Damage Mechanics: Use a homogenized approach with micro-scale considerations.

5. Coupled Multi-physics Simulation

  • Integration: Combine thermal, mechanical, and material degradation models.
  • Software: Utilize FEA with custom subroutines for dynamic material properties.

6. Cycle and Transient Analysis

  • Cyclic Braking: Simulate multiple braking events to capture cumulative damage.
  • Time Step Management: Ensure small time steps for transient heat transfer and stress analysis.

7. Validation

  • Experimental Data: Compare simulation results with real-world tests for accuracy.
  • Adjustments: Tune models based on validation findings.

8. Considerations and Simplifications

  • Surface Topography: Account for changes and wear debris effects.
  • Oxidation Effects: Consider environmental factors affecting carbon degradation.
  • Computational Efficiency: Use coarser meshes where possible without losing accuracy.

9. Final Simulation

  • Execution: Run simulations to observe thermal fade and wear over repeated braking events.
  • Analysis: Evaluate friction coefficient changes and wear patterns.

This structured approach ensures a comprehensive analysis, integrating multiple disciplines to accurately model the complex interactions during high-speed braking.