Steel Angle Deflection Calculator

Formula Used

The calculator first estimates the steel angle section properties from two rectangles minus the overlapping square.

Section area: A = t × V + H × t − t²

Centroid: ȳ = Σ(Ay) / ΣA

Second moment of area: Ix = Σ(I + A d²) with the overlap removed

It then applies classic elastic beam equations using E, I, span, and load. Four beam cases are included: cantilever with end point load, cantilever with full span uniform load, simply supported with center point load, and simply supported with full span uniform load.

Deflection depends strongly on span length. A small span increase can produce a much larger deflection because span appears as L³ or L⁴ in these formulas.

How to Use This Calculator

1. Select the loading case that matches your beam condition.
2. Enter the span in meters and the elastic modulus in GPa.
3. Enter vertical leg, horizontal leg, and thickness in millimeters.
4. Enter either a point load or a uniform load.
5. Set the allowable deflection ratio such as L/240 or L/360.
6. Use the custom Ix box when you have manufacturer data.
7. Press the calculate button to show the result above the form.
8. Review the graph, utilization, and export options.

This tool is useful for quick checks. It is not a substitute for a full structural design review.

Example Data Table

FAQs

1. What does this calculator find?

It estimates steel angle beam deflection, rotation, section properties, allowable movement, utilization, and a plotted deflection curve for common loading cases.

2. Does it use exact angle section properties?

By default, it uses a geometric estimate from two rectangles minus overlap. That ignores root radii and fillets. Use custom Ix for exact catalog data.

3. Which units should I enter?

Enter span in meters, modulus in GPa, leg dimensions in millimeters, point load in kN, and uniform load in kN per meter.

4. What is allowable deflection ratio?

It is the movement limit expressed as span divided by a chosen number, such as L/240 or L/360. Higher divisors mean tighter limits.

5. Why is span so important?

Beam deflection changes rapidly with span because beam equations include L cubed or L to the fourth power. Small span increases can matter a lot.

6. What does the graph show?

The graph plots beam position on the horizontal axis and downward deflection in millimeters on the vertical axis for the selected beam case.

7. Can I use this for design approval?

Use it for preliminary checks only. Final approval should use exact section data, code requirements, connection effects, and professional structural review.

8. When should I enter custom Ix?

Enter custom Ix when a steel handbook, catalog, or manufacturer gives a more accurate second moment of area than the simplified geometric estimate.