| Product(s): | SACS |
| Version(s): | All |
| Area: | Fatigue |
Community Question:
how can I consider the eccentricity or fabrication misalignment in my analysis?
What is the meaning of the next 2 Warnings in my analysis :
- " WARNING - The inline tubular thickness of *** cm and ***cm results in a thickness ratio greater than 2.0 which may cause an unconservative stress concentration factor"
- " WARNING - Invalid geometry for inline tubular stress concentration factors"
Answer
For the misalignment in sacs, you must use the card FTOPT3, in which you can set the misalignment in terms of percent of diameter or percent of smaller thickness, Sacs have a default the next value
- NORSOK - DEFAULT 1.0 PERCENT OF DIAMETER
- DNV - DEFAULT 20.0 PERCENT OF SMALLER THICKNESS
Regarding the first warning message, if you work with the DNV C203 when using equation 3.3.5 for the calculation of SCF at tubular butt welds, it is recommended to use a thickness ratio of less than 2.0. SACS follows this procedure and warns the user if this recommendation is violated. with the next message
- " WARNING - The inline tubular thickness of *** cm and ***cm results in a thickness ratio greater than 2.0 which may cause an unconservative stress concentration factor
The second warning message populates when the percentage difference of the inner diameter ratio in tubular transition does not meet the tolerance value (0.001). In other words, when there is a tubular transition (second tubular section with an inner diameter of ID2 and first tubular section with an inner diameter of ID1), the warning message comes up if |ID2-ID1|/ID1 becomes less than the tolerance value (0.001).
- " WARNING - Invalid geometry for inline tubular stress concentration factors"