Calculadora de Tensão em Viga — Formula

Bending Stress in Beams

The flexure formula relates the internal bending moment to the normal stress at any fibre of the cross-section.

Formula

sigma = M c / I

M is the bending moment, c is the perpendicular distance from the neutral axis to the outermost fibre, and I is the second moment of area about the neutral axis. The result is the peak tensile or compressive stress at the extreme fibre.

Exemplo Resolvido

A steel beam with I = 8356 cm^4, depth 300 mm (c = 150 mm), under a moment of 50 kN-m.

  1. Convert moment: 50 kN-m = 50 x 10^6 N-mm
  2. Convert inertia: 8356 cm^4 = 8356 x 10^4 mm^4 = 8.356 x 10^7 mm^4
  3. sigma = (50 x 10^6 x 150) / (8.356 x 10^7)
  4. sigma = 7.5 x 10^9 / 8.356 x 10^7 = 89.76 MPa