1. What is the Angle of Repose?

Definition: The steepest angle at which a pile of granular material can remain stable without sliding.

Purpose: Important in engineering, agriculture, and material science for designing storage systems, conveyor belts, and assessing slope stability.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \theta \) — Angle of repose (degrees)
• \( \mu \) — Coefficient of friction (dimensionless)

Explanation: The arctangent of the coefficient of friction gives the angle at which gravitational forces equal frictional forces.

3. Importance of Angle of Repose

Details: Critical for designing storage bins, hoppers, and conveyor systems. Affects material flow characteristics and stability.

4. Using the Calculator

Tips: Enter the coefficient of friction (μ) for your material. Typical values range from 0.3 (sand) to 0.8 (angular gravel).

5. Frequently Asked Questions (FAQ)

Q1: What's a typical coefficient of friction for common materials?
A: Dry sand ~0.6, Wheat ~0.5, Coal ~0.7, Gravel ~0.8.

Q2: How does moisture affect the angle of repose?
A: Moisture generally increases cohesion, allowing steeper angles up to a point before saturation causes sliding.

Q3: What's the difference between static and dynamic angle of repose?
A: Static is for stationary piles, dynamic is for moving materials (typically 5-10° less).

Q4: How do particle shape and size affect the angle?
A: Angular particles have higher angles than rounded ones. Smaller particles generally have higher angles due to cohesion.

Q5: Can this be used for non-granular materials?
A: The formula applies best to free-flowing granular materials. Cohesive materials may require different analysis.