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Euler-Bernoulli Beam Deflection Calculator

Calculates maximum deflection and bending moment for simply supported and cantilever beams according to Euler-Bernoulli beam theory.

Structural Elastic Bending Solver

Euler-Bernoulli Beam Deflection

Calculates maximum elastica deflection δ_max, bending moments M_max, reaction forces, and IBC building code span limits.

13.1 ft
10.0 kN
Steel: 200, Al: 69
50.0 × 10⁶ mm⁴
For bending stress
Euler-Bernoulli Elastic Deflection Profile & SupportsRa = 5 kNRb = 5 kNP = 10.0 kNδ_max = 1.33 mmSpan L = 4 m
Maximum Beam Deflection (δ_max)
1.33 mm
Equivalent to 0.052 inches | Span Ratio: L / 3000
Building Code ComplianceMeets Strictest L/480 Ceiling Limit

IBC limit: L/360 for live loads, L/240 total.

Max Bending Moment M_max10 kN·m7,375.6 ft·lb
Extreme Fiber Bending Stress20 MPaσ_b = (M · c) / I at outer fiber
Governing Euler-Bernoulli Elastic Equations

Deflection: δ_max = (P · L³) / (48 · E · I)

Moment: M_max = (P · L) / 4

Reaction Forces: Ra = 5 kN, Rb = 5 kN

What is Beam Deflection?

Beam deflection is the vertical displacement of a structural beam under the influence of an applied lateral load, governed by the span length, Young’s modulus, and area moment of inertia.

Formula & Step-by-Step Calculation

δ_max = (P · L³) / (48 · E · I) [Simply Supported Point Load], M_max = (P · L) / 4

Euler-Bernoulli deflection and bending moment formula.

Worked Step-by-Step Examples

Example 1

Simply supported 4m steel beam (E=200 GPa, I=50×10⁶ mm⁴) with 10 kN center load

Solution: Max Deflection: 1.33 mm (L/3000), Max Moment: 10.00 kN·m
• δ = (10,000 × 4³) / (48 × 200e9 × 50e-6) = 640,000 / 480,000,000 = 0.00133 m = 1.33 mm

Common Real-World & Academic Use Cases

  • ✓ Floor joist structural deflection building code verification (L/360 rule)
  • ✓ Crane gantry girder bending moment sizing
  • ✓ Bridge deck longitudinal support beam checks

How to Use the Euler-Bernoulli Beam Deflection Calculator

1

Select Support Condition

Choose Simply Supported or Cantilever.

2

Enter Span & Applied Load

Input length (m) and force (N).

3

Read Deflection

Inspect maximum deflection in mm and L/span ratio.

Frequently Asked Questions

Q: What is the L/360 building deflection limit?

A common structural building code threshold specifying that a floor beam under live load must not deflect by more than 1/360th of its clear span length to prevent plaster ceiling cracking.

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