Performance-based methods:
Critical temperature method:
550°C for unprotected beams
620°C with intumescents
Load ratio approach:
R = η_fi×(F_Ed/F_Rd)
Advanced calculation models:
Finite element analysis
Eurocode 3 Part 1-2
How do you specify paint systems?
Coating specifications:
Primer:
Zinc-rich epoxy (75μm)
Adhesion >5MPa
Intermediate:
Micaceous iron oxide (125μm)
DFT tolerance ±20μm
Topcoat:
Polyurethane (50μm)
Color retention >10 years
What BIM applications streamline fabrication?
Digital workflows:
Model-based detailing:
Tekla Structures
Advance Steel
CNC machine integration:
Plasma cutting (±0.5mm)
Drilling (±0.2mm)
Automated quantity takeoffs:
99% material utilization
30% waste reduction
How are vibration effects analyzed?
Modal analysis steps:
Natural frequency:
f_n = (π/2)×√(EI/mL⁴)
Footfall analysis:
1.5-2.5Hz critical range
8% damping ratio typical
Response factor:
R = 1.8 for offices
R <4 acceptable
What causes weld distortion?
Heat input effects:
Angular distortion: 1-3° per pass
Longitudinal shrinkage: 0.5mm/m
Transverse contraction: 1-2mm
Control methods:
Balanced welding sequence
Preset angles
Temporary stiffeners
