1. What is the Interior Support Moment Formula?

The interior support moment formula calculates the bending moment at the interior supports of a 3-span continuous beam under uniformly distributed load. This is a fundamental calculation in structural engineering for beam design and analysis.

2. How Does the Calculator Work?

The calculator uses the interior support moment formula:

Where:

• \( M_{interior} \) — Interior support moment (Nm)
• \( w \) — Uniformly distributed load (N/m)
• \( L \) — Span length (m)

Explanation: This formula provides the maximum bending moment at the interior supports of a 3-span continuous beam with equal spans and uniform loading.

3. Importance of Interior Support Moment Calculation

Details: Accurate moment calculation is crucial for proper structural design, ensuring beams can withstand applied loads without failure, and for determining required reinforcement in concrete beams or section sizes in steel beams.

4. Using the Calculator

Tips: Enter the distributed load in N/m and span length in meters. Both values must be positive numbers greater than zero for valid calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is a 3-span continuous beam?
A: A beam that rests on four supports with three equal spans between them, creating continuity across multiple supports.

Q2: When is this formula applicable?
A: This formula applies to 3-span continuous beams with equal spans and uniformly distributed loads across all spans.

Q3: What are typical units for this calculation?
A: Load is typically in N/m, span length in meters, and the resulting moment in Newton-meters (Nm).

Q4: Are there limitations to this formula?
A: This formula assumes equal spans, uniform loading, and identical beam properties across all spans. Different conditions require more complex analysis.

Q5: How does this compare to simple beam moment formulas?
A: Continuous beams typically have lower maximum moments than simple beams due to moment redistribution across multiple supports.