Beam Calculator
Calculate reactions, shear force, bending moment, and deflection for beams.
Reaction at A (RA)
25.00 kN
Reaction at B (RB)
25.00 kN
Max shear force
25.00 kN
Max bending moment
31.25 kN·m @ 2.50m
Bending Moment Diagram (sagging positive)
Simply supported beam · Deflection δ_max = 5wL⁴ / (384EI)
Relative δ (EI=1): 81.3802 kN·m³
Relative δ (EI=1): 81.3802 kN·m³
Simply supported beam analysis
Calculate support reactions, maximum shear force, bending moment, and deflection for beams under UDL, point load, or applied moment. Visualise the bending moment diagram instantly.
Frequently asked questions
- What is a simply supported beam?
- A simply supported beam is supported at both ends with pinned supports. It can rotate freely at the supports but cannot move vertically. This is the most common beam configuration in structural analysis.
- What is the maximum bending moment for a UDL beam?
- For a simply supported beam with uniform distributed load w over span L, the maximum bending moment is M = wL²/8, occurring at the midspan.
- What is EI in deflection formulas?
- EI is the flexural rigidity of the beam — E is Young's modulus (material stiffness) and I is the second moment of area (section stiffness). Higher EI means less deflection.
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