Beam Deflection

Maximum deflection, moment and shear of a linear-elastic prismatic beam per Euler-Bernoulli theory. Pick an IPE, HEA, HEB or RHS section or enter your own properties.

StaticsEuler-BernoulliIPE / HEA / HEB
↑ ↓ steps the value
Maximum deflection δ_max1.38mm
Maximum moment M_max
7.5 kN·m
Maximum shear V_max
5 kN
Bending stress σ = M / Wx
38.7 MPa
Deflection ratio
L / 2176
Flexural rigidity EI
4,080 kN·m²
  • Serviceability: L/2176 — common limit L/250
  • Utilisation against S235 yield: 16 %
METHOD

How it is calculated

Simply supported, point:  δ = PL³ / 48EI     M = PL / 4
Simply supported, UDL:    δ = 5wL⁴ / 384EI   M = wL² / 8
Cantilever, tip load:     δ = PL³ / 3EI      M = PL
Cantilever, UDL:          δ = wL⁴ / 8EI      M = wL² / 2
σ = M / Wx
ASSUMPTIONS & NOTES
  • Self-weight is not included; add the section mass (kg/m × 9.81 / 1000 kN/m) to the distributed load if needed.
  • Shear deformation and lateral buckling are ignored. Check lateral-torsional buckling for long, slender beams.
  • L/250 is a general serviceability limit; use code limits for floors, crane runways etc.

Results are for preliminary design and checking; base the final design on the governing standard and safety factors.