Pipe Bending Stress Calculator

Bending Stress:
σ_b = M / Z

Deflection (Simply Supported):
δ = 5wL⁴ / (384EI)

Section Modulus:
Z = π(OD⁴-ID⁴) / (32×OD)

Support Spacing: ASME B31.8 recommends evaluating combined stresses for unsupported spans. Consider soil support, thermal expansion, and seismic loads.

Load Categories:
• Sustained: Dead weight, pressure
• Occasional: Wind, seismic, hydro test
• Thermal: Expansion/contraction

Acceptance Criteria:
• Combined: ≤ 0.75 SMYS (§833.4)
• Occasional: ≤ F×E×T×SMYS
• Deflection: L/240 typical limit

Design Considerations:
Use proper support types to minimize bending. Fixed supports create moments; pinned supports allow rotation. Consider stress intensification factors at fittings.

ASME B31.8-2020
• §833.4 - Combined stress criteria
• §841.1.6 - Design factors (Table)
• §841.1.8 - Temperature derating

API 1102
Steel Pipeline Crossing Railroad and Highway Rights-of-Way

ASCE 7
Minimum Design Loads (wind, seismic)