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Beam Deflection Formula:
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Beam deflection refers to the degree to which a structural element is displaced under a load. It is a critical factor in structural engineering that affects both the performance and safety of building components.
The calculator uses the standard beam deflection formula:
Where:
Explanation: This formula calculates the maximum deflection of a simply supported beam with a uniformly distributed load.
Details: Proper deflection calculation is essential for ensuring structural integrity, preventing excessive sagging, and meeting building code requirements for various applications.
Tips: Enter all values in the specified units. Load should be in plf, span in feet, modulus in psi, and moment of inertia in in⁴. All values must be positive numbers.
Q1: What is a typical acceptable deflection limit?
A: Most building codes limit deflection to L/360 for live loads and L/240 for total loads, where L is the span length.
Q2: Does this formula work for all beam types?
A: This specific formula applies to simply supported beams with uniformly distributed loads. Other support conditions require different formulas.
Q3: How does material affect deflection?
A: Different materials have different modulus of elasticity values. Steel has a higher modulus than wood, meaning it will deflect less under the same load.
Q4: What if my beam has a point load instead of distributed load?
A: Point loads require a different deflection formula: δ = P L³ / (48 E I) for a center point load on a simply supported beam.
Q5: Why is the span length raised to the fourth power?
A: Deflection is highly sensitive to span length. Doubling the span increases deflection by a factor of 16 (2⁴), making span length the most significant factor in deflection calculations.