Utilizing Finite Element Method (FEM) and thermal distribution analysis, MES conducts precise structural assessments, ensuring vessel integrity and performance under various operational conditions. Steel grades are meticulously selected and verified to ensure full compliance with cryogenic conditions and applicable Rules.
Although the tanks are constructed using cryogenic-grade 9% Ni or stainless steel, suitable for handling such low temperatures without compromising material toughness and mechanical properties, the ship’s hull structures are built with carbon steel grades commonly used in the shipbuilding industry. These steels have a minimum operating temperature that must never be reached or exceeded to ensure the preservation of their mechanical properties.
Steel grades requested by IGC Code and IGF Code and their limit temperatures are reported in the following table:
The temperature distribution on the hull depends on the following parameters:
- Tank temperature and insulation efficiency;
- Distribution of thermal and fire insulation on the ship;
- Configuration of the tanks’ hold space and surrounding areas;
- Boundary temperature conditions (ambient air and seawater temperature).
To perform this calculation, a comprehensive finite element (FE) model must be prepared, including the tanks, tanks’ hold space, thermal and fire insulation, surrounding spaces, and part of the outer hull.
MES also performs FEM vibration analysis to ensure the structural integrity and operational efficiency of ship components under dynamic loading conditions. This type of analysis is critical for identifying potential resonance issues, minimizing vibration-induced fatigue, and enhancing overall safety and comfort:
FEM calculations are also performed for structural verifications to ensure that the ship’s structures can withstand operational and extreme loading conditions. These analyses are essential for validating design compliance with international standards and classification society requirements while optimizing material usage and maintaining safety margins.
Below are some examples of FEM-based structural verifications, showcasing the range of analyses performed to ensure the integrity and reliability of ship structures:
