Calcolatrice Forze nel Traliccio — Formula
## Truss Chord Forces
For a parallel-chord truss carrying uniform load, the midspan chord forces can be approximated from the equivalent beam moment.
### Derivation
The midspan moment for equivalent simply supported beam: M = W L / 8.
The chord force equals the moment divided by the lever arm (truss depth): **F_chord = W L / (8 h)**
The bottom chord is in tension and the top chord is in compression with approximately equal magnitude at midspan.
For a parallel-chord truss carrying uniform load, the midspan chord forces can be approximated from the equivalent beam moment.
### Derivation
The midspan moment for equivalent simply supported beam: M = W L / 8.
The chord force equals the moment divided by the lever arm (truss depth): **F_chord = W L / (8 h)**
The bottom chord is in tension and the top chord is in compression with approximately equal magnitude at midspan.
Esempio Risolto
A 12 m span Pratt truss, 2 m deep, carrying a total load of 120 kN.
- Equivalent beam moment: M = 120 x 12 / 8 = 180 kN-m
- Chord force = 180 / 2 = 90 kN (tension in bottom chord)
- Support reaction = 120 / 2 = 60 kN