Deformed Tank FEA Assessment

SERVICE LINES

• Mechanical Engineering

INDUSTRY SECTOR

• Energy

• Infrastructure

• Petrochemical/Chemical Processing

• Terminals/Ports

LOCATION
Queensland, Australia

PROJECT SUMMARY
The installation of a nozzle on the bottom strake of a flat-bottomed tank had resulted in unacceptable out of roundness. This left the tank susceptible to buckling collapse in certain load conditions.

SCOPE​
A 3D laser scan of a portion of the shell containing the distortion was provided, and from this Five-D performed assessment to determine if the tank still had sufficient protection against buckling.

This involved:

• Creating a representative geometry of the tank including the 3D scan data of the defect.

• Conducting Finite Element Method elastic-plastic analysis and assessment to API 579-1 Part 8 Level 3 using ASME VIII Div. 2 Part 5 rules.

• Assessing protection against plastic collapse and buckling in design and wind load conditions.

CHALLENGES
Integration of the 3D scan data into the idealised representative tank geometry.

• The methodology for cutting the integrating the 3D scan data had to be carefully considered to minimise computational processing time without compromising fidelity and accuracy.

OUTCOME​
The assessment was completed successfully, showing that the tank was fit for service in all the design load conditions, and providing detail on the potential load conditions that would produce the worst effect on the deformed tank. Resulting in significant savings in time, materials and effort while maintaining a high level of operational integrity and safety.