梁应力计算器 — 公式
## 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.
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.
计算示例
A steel beam with I = 8356 cm^4, depth 300 mm (c = 150 mm), under a moment of 50 kN-m.
- Convert moment: 50 kN-m = 50 x 10^6 N-mm
- Convert inertia: 8356 cm^4 = 8356 x 10^4 mm^4 = 8.356 x 10^7 mm^4
- sigma = (50 x 10^6 x 150) / (8.356 x 10^7)
- sigma = 7.5 x 10^9 / 8.356 x 10^7 = 89.76 MPa