Steel in Steel
The Steel-In-Steel (SIS) or Steel-Cased-Pipeline (SCP) module allows modelling structures where an inner (medium) steel pipe is encased by an outer (casing) steel pipe for either thermal isolation or as an additional safety precaution. The two pipes can be connected by either fixed connections or roller connections. The latter allows axial movements of the inner pipe with respect to the outer pipe. Both trench-laid SIS sections and horizontally directional drilled (HDD) sections can be modelled. Any movement of the outer pipe is automatically transferred to the inner pipe through the rollers and fixed connections. Movements of the inner pipe (e.g. thermal loads or pre-stressing) are transferred to the outer pipe as well.
A short demo: