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Bending stress is normal stress from moment loading, the primary stress in beams. It varies linearly across the section, maximum at outer fibers.

Формула

Calculate: σ = M×c/I where M is moment, c is distance from neutral axis, I is moment of inertia
M
I/c) — I/c)
I
I value — Variable used in the calculation

Водич корак по корак

  1. 1Calculate: σ = M×c/I where M is moment, c is distance from neutral axis, I is moment of inertia
  2. 2Or: σ = M/S where S is section modulus (S = I/c)
  3. 3Results show stress distribution

Worked Examples

Инпут
M = 50 kN·m, I = 1×10⁹ mm⁴, c = 200 mm
Резултат
σ = 10 MPa at extreme fiber
Safe stress level

Common Mistakes to Avoid

  • Using average stress instead of maximum stress
  • Forgetting compression and tension can develop simultaneously

Frequently Asked Questions

Why does stress vary across the beam?

Outer fibers experience maximum stretch/compression; inner material near neutral axis experiences less.

How is section modulus useful?

S directly gives maximum stress: σ_max = M/S, simpler than calculating I and c separately.

Подешавања