1. What is Diameter of Roller or Rocker Calculator?

Definition: This calculator determines the required diameter of rollers or rockers in structural applications based on allowable bearing stress and steel yield stress.

Purpose: It helps engineers design appropriate roller/rocker diameters that can safely handle specified loads without exceeding material limits.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( d_r \) — Diameter of rollers and rockers (meters)
• \( F_p \) — Allowable bearing stress (Pascals)
• \( F_y \) — Yield stress of steel (Pascals)

Explanation: The formula accounts for the relationship between bearing capacity and material yield strength, with empirical constants derived from engineering practice.

3. Importance of Proper Roller/Rocker Diameter

Details: Correct diameter calculation ensures structural integrity, prevents premature failure, and maintains proper load distribution in expansion joints and bearings.

4. Using the Calculator

Tips: Enter the allowable bearing stress (F_p), steel yield stress (F_y), and tolerance percentage. F_y must be > 13 Pa.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical tolerance for roller diameters?
A: ±5% is common, but this may vary based on application requirements.

Q2: Why is there a minimum F_y value?
A: The formula becomes invalid when F_y ≤ 13 due to division by zero or negative values.

Q3: How does bearing stress affect diameter?
A: Higher allowable bearing stress permits smaller diameters, while lower stress requires larger diameters.

Q4: What steel grades are appropriate for rollers/rockers?
A: Typically A36 (F_y=250 MPa) or higher strength steels, depending on load requirements.

Q5: Does this account for dynamic loads?
A: The basic formula is for static loads. Dynamic applications may require additional safety factors.

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