Dnv-rp-f118 [work] May 2026

Short summary — key points from DNV‑RP‑F118

Scope: Methods to estimate ice loads on ships, offshore structures and marine installations in level ice and broken-ice conditions for design and assessment.
Ice properties: Classification of ice types, typical mechanical properties (compressive strength, flexural strength, Young’s modulus) and how temperature, salinity and grain structure affect them.
Load-generating mechanisms: Descriptions of failure modes (flexure, crushing, splitting, bending, indentation) and interaction scenarios (continuous drift, grounded ice, ridges, icebergs).
Design ice thickness and statistics: Guidance on selecting representative ice thickness, return periods, and using probabilistic approaches for extreme-event loads.
Deterministic load models: Empirical and semi-empirical formulas for local and global ice pressures, bearing capacity, and ice-structure contact pressure distributions.
Probabilistic methods: Treatment of uncertainties in ice properties, encounter frequency, and variables; methods to derive characteristic loads for target reliability levels.
Dynamic interactions: Consideration of relative motions, velocity effects, and energy dissipation during ice impacts.
Numerical modelling: Recommendations for using FEM, discrete-element and other computational models; calibration and validation against tests/field data.
Testing and validation: Recommended laboratory and field tests for deriving parameters and validating models (compression, bending, indentation, model-scale interaction tests).
Safety and design checks: Suggested acceptance criteria, load combinations, and considerations for inspection, monitoring and operational mitigation.

One of the most rigorous aspects of DNV-RP-F118 is its demand for statistical confidence. Unlike simpler standards, it requires:

Per F118: Screening → low probability of rapid failure, but cumulative strain is a concern.
Assessment: Finite element analysis shows annual plastic strain of 0.2% — below the 1% ULS strain limit for girth welds.
Mitigation: No immediate remediation; install fiber-optic strain gauges and re-assess every 2 years.
Outcome: Cost-effective monitoring instead of expensive rerouting or sleeving.

is often cited just to reach basic statistical confidence (e.g., 90% Probability of Detection with 95% confidence). Complex Welds dnv-rp-f118

DNV-RP-F118 is a recommended practice titled Pipe girth weld automated ultrasonic testing system qualification and project specific procedure validation Short summary — key points from DNV‑RP‑F118