Calculateur de Flèche de Poutre Gratuit
Calculez la déflexion d'une poutre sous charge. Déterminez la flèche maximale selon le matériau, la section et la portée.
Max Deflection
0.000 in
Max Deflection vs Beam Span
Formule
Simply Supported Beam Deflection
Delta_max = 5wL^4 / (384EI)
Where w is the load per inch, L is the span in inches, E is the modulus of elasticity, and I is the moment of inertia. Common deflection limits are L/360 for floors and L/240 for roofs.
Exemple Résolu
12 ft beam, 200 lb/ft load, E = 1,700,000 psi, I = 98 in^4.
- 01w = 200/12 = 16.67 lb/in
- 02L = 144 in
- 03Delta = 5 x 16.67 x 144^4 / (384 x 1,700,000 x 98)
- 04Delta = 0.283 in
- 05L/360 = 0.40 in; deflection is within limits.
Questions Fréquentes
What is L/360?
L/360 means the allowable deflection is the span divided by 360. For a 12 ft (144 in) span, the limit is 144/360 = 0.40 inches. This is the typical limit for floor beams under live load.
Where do I find E and I values?
E depends on the material (wood: 1.2-1.8M psi, steel: 29M psi). I depends on the cross-section; look it up in beam tables or calculate from the section dimensions.
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