Appearance
Specialized Steel Design Checks
CivilKit Studio includes specialized design checks beyond the standard AS 4100 member capacities. Access them via the Steel checks button in the toolbar.
Check Types
| Check | Standard | Purpose |
|---|---|---|
| Fire | AS 4100:2020 Section 12 | Temperature-dependent capacity for fire resistance |
| Fatigue | AS 4100:2020 Section 11 | S-N curve fatigue with Palmgren-Miner damage |
| Cellular beam | AISC DG31 | Castellated/cellular beam net/gross properties |
| Tapered member | AS 4100 + AISC DG25 | Web-tapered I-section member design |
| Composite beam | AISC 360-16 | Steel-concrete composite member design |
How to Use
- Open the panel - Click "Steel checks" in the toolbar
- Select check type - Choose from the dropdown
- Enter inputs - Either manually or:
- Select a member in the model
- Click "Fill from member" to auto-populate section dimensions
- Run check - Click "Run check"
- Add to report - Click "Add to report" to save to the PDF report
Fire Check
Inputs
| Field | Description | Units |
|---|---|---|
| Ambient capacity | Design capacity at ambient temperature | MPa |
| Fire demand | Required capacity at fire temperature | MPa |
| Fire duration | Standard fire exposure time | minutes |
| Section factor | Hp/A (heated perimeter / area) | m⁻¹ |
| Exposure | Four-sided or three-sided | - |
Outputs
- Steel temperature at fire time
- Limiting temperature
- Temperature margin
- Load ratio
- OK/OVER status
WARNING
Valid for 500-750°C and section factors 2-35 m²/tonne (Hp/A 15-275 m⁻¹).
Fatigue Check
Inputs
| Field | Description | Units |
|---|---|---|
| Stress spectrum | Stress range pairs (cycles, MPa) | - |
| Detail category | Cat160-Cat36 per Table 11.5.1 | - |
| Thickness t | Thickness at detail location | mm |
| Yield strength fy | Steel yield strength | MPa |
| Capacity factor phi | Typically 0.7 | - |
| Apply beta_tf | Thickness correction for welds | - |
Outputs
- Damage sum
- Applicable flag
- OK/OVER status
TIP
Thickness correction β_tf = (25/t)^0.25 applies for transverse welds >25mm.
Cellular Beam Check
Inputs
| Field | Description | Units |
|---|---|---|
| Depth d | Overall beam depth | mm |
| Flange bf | Flange width | mm |
| Flange tf | Flange thickness | mm |
| Web tw | Web thickness | mm |
| Hole do | Opening diameter | mm |
| Spacing s | Hole center-to-center | mm |
| Length | Member length | mm |
| Effective length Le | For LTB | mm |
| fy | Yield strength | MPa |
| Alpha m | Moment gradient case (0-4) | - |
| Alpha b | Section constant | - |
Outputs
| Output | Meaning |
|---|---|
| φM_gross | Full-section flexural capacity |
| φM_net | Net-section moment capacity |
| φM_b | LTB capacity |
| φV_net | Net vertical shear |
| φM_vierendeel | Vierendeel moment capacity |
| φV_web_post | Web-post shear capacity |
WARNING
Uses conservative strut-on-elastic-foundation model for web-post buckling. Verify against AISC DG31 examples.
Tapered Member Check
Inputs
| Field | Description | Units |
|---|---|---|
| Length | Member length | mm |
| Depth dA | Depth at end A | mm |
| Depth dB | Depth at end B | mm |
| Flange bf | Flange width | mm |
| Flange tf | Flange thickness | mm |
| Web tw | Web thickness | mm |
| Effective length Le | For buckling | mm |
| fy | Yield strength | MPa |
| Alpha m | Moment gradient case (0-4) | - |
| Alpha b | Section constant | - |
Outputs
| Output | Meaning |
|---|---|
| x_govern_mm | Governing section location |
| d_govern_mm | Governing depth |
| φMs | Section capacity at shallowest |
| φMb | Member LTB capacity |
| φNc | Compression capacity |
| Taper ratio | (dA-dB)/dA |
WARNING
Uses "shallowest-section" approach - may be conservative where governing limit state is at deep end.
AISC 360 Composite Beam Check
Inputs
| Field | Description | Units |
|---|---|---|
| As | Steel area | mm² |
| Depth d | Steel section depth | mm |
| fy | Steel yield strength | MPa |
| Slab tc | Concrete thickness | mm |
| f'c | Concrete strength | MPa |
| Effective width b | Tributary width | mm |
| Stud diameter | Shear stud diameter | mm |
| Stud fu | Stud ultimate strength | MPa |
| Number of studs | Stud count | - |
| phi | Capacity factor (0.9) | - |
Outputs
| Output | Meaning |
|---|---|
| φMn_full | Full shear connection moment |
| φMn_partial | Partial shear connection moment |
| Degree of shear connection | Ratio of actual to full |
| Horizontal shear | Vh from composite action |
| Stud shear | Total stud shear capacity |
WARNING
Uses simplified plastic-stress block. For full accuracy, PNA location logic is needed.
Report Integration
Each successful check adds a calculation card to the report with:
- All inputs and outputs
- Standard header (AS 4100 or AISC 360)
- Exportable via File → Report (PDF)
See the standalone steel-checks-user-guide.md for detailed workflow instructions.