Complete Guide to Truss Analysis
The Truss Analysis Calculator uses the method of joints to determine member forces in common truss types. Essential for roof, bridge, and industrial structures. Pair with Beam Load and Bridge Load calculators.
What is a Truss?
Pin-jointed framework of triangles transmitting axial forces only.
- Zero-force members: No load
- Tension/Compression: Axial only
- Stable & determinate: m = 2j - 3
Common Types
- Warren: Equilateral triangles
- Pratt: Vertical members in tension
- Howe: Vertical members in compression
Method of Joints
ΣF_x = 0, ΣF_y = 0 at each joint
Step-by-Step Process
- Find reactions
- Start at support joint
- Solve sequentially
- Check equilibrium
Example: Warren Truss
L=12m, 6 panels, h=2.4m, uniform load 20 kN/m:
- Top chord: 60 kN (C)
- Bottom chord: 60 kN (T)
- Diagonal: 34.6 kN (T/C)
Typical Member Forces
| Type | Tension | Compression |
|---|---|---|
| Warren | Bottom chord | Top chord |
| Pratt | Verticals | Diagonals |
| Howe | Diagonals | Verticals |
Applications
- Roofs: Factories, hangars
- Bridges: Pedestrian, railway
- Towers: Transmission, cranes
Best Practices
- Use equal panel spacing
- Optimize height (L/8 to L/12)
- Check buckling in compression
- Provide bracing
Common Mistakes
- Assuming bending in members
- Wrong reaction direction
- Skipping zero-force members
- Ignoring self-weight
Advanced Topics
- Space trusses
- Finite element analysis
- Prestressed trusses
- Composite materials
Conclusion
Efficient truss design minimizes material while ensuring safety. Our Truss Analysis Calculator delivers instant member forces for standard configurations. Integrate with Beam Load for complete structural systems. Build lighter, stronger!