DNV RP-C203 (2024) Fatigue Standard in SDC Verifier

About Standard

DNV RP-C203 (2024) defines fatigue assessment procedures for welded and non-welded offshore steel structures. SDC Verifier implements the standard per the 2024 edition, using Method B (Chapter 4.8) for stress extraction and applying environment-specific rules from Chapters 2.4.4 (air) and 2.4.5 (seawater with cathodic protection).

Key Fatigue Parameters:

Environment Type: Air by default; seawater CP configurable
Hot Spot Stress: Offset at 0.5t from weld toe or shell intersection
SN Curve Assignment:
- Global SN curve for non-welded components
- Directional SN curves (X = parallel, Y = perpendicular) for welds
- Weld intersections: automatically assign lowest fatigue class
- Angular stress interpolation via Table F-1 (Appendix F.5)

Thickness Factor: Reference thickness = 25 mm (non-tubular), 16 mm (tubular). Thickness exponent K as per Tables 2-1 to 2-4. Can be edited per weld group or element type.

Stress Factor: By default, a 1.12 hot spot amplification factor is applied (can be disabled).

Other Features:

C2* curve override for user-defined fatigue curves
Method B valid for both shell and solid models
Uses fatigue life estimation with SN curves (stress-life method)
Supports carbon-manganese steel with yield strength < 960 MPa

This standard is essential for verifying welded joints and critical details in offshore topsides, jackets, marine terminals, wind turbine foundations, and similar cyclically loaded structures.

Key Benefits of SDC Verifier