Steel · Members & beams
Tension member: net area & stagger calculator
Gross yield and net-section fracture with staggered holes (s²t/4g) and the correction factor kt for eccentric end connections.
Standard: AS 4100 Cl 7.2, 7.3, 9.1.10
Inputs in the worked example
The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.
| Input | Value | Unit |
|---|---|---|
| Gross area | 1600 | mm² |
| Thickness | 8 | mm |
| Holes in the failure path | 2 | |
| Hole diameter | 22 | mm |
| Staggered gauge spaces crossed | 1 | |
| Stagger pitch s | 50 | mm |
| Gauge g | 60 | mm |
| Correction factor kt | 0.85 equal angle by one leg | |
| fy | 320 | MPa |
| fu | 440 | MPa |
| Design tension N* | 380 | kN |
Worked example — results
| Result | Value | Unit |
|---|---|---|
| Net area Ag − n dh t + Σ s²t/4g | 1,331 | mm² |
| φ Ag fy | 460.8 | kN |
| φ 0.85 kt An fu | 380.9 | kN |
| φNt | 380.9 | kN |
- ✓ N* ≤ φNt
Method, formulas and assumptions
- Net area Ag − n dh t + Σ s²t/4g = MIN(1600,1600-2*22*8+1*50^2*8/(4*60)) = 1331.3 mm²
- φ Ag fy = 0.9*1600*320/1000 = 460.8 kN
- φ 0.85 kt An fu = 0.9*0.85*0.85*1331.3*440/1000 = 380.91 kN
- φNt = MIN(460.8,380.91) = 380.91 kN
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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.