We design vertical supported vessels and I'm interested to
see if how others would model leg forces (static, water filled
weight) including force translation to repad and shell given a two
considerations. 1) Application of the mass load using symmetry -
how much of the cylindrical shell is required to adequately
represent translation of the mass load from COG to the shell to the
leg. 2) Reaction of the leg to some structural steel (W-beam) vs
infinitely stiff restraint of the pad vs other restraint options.

After some trial and error, it is obvious that a wide range of results are possible depending upon application of load and stiffness of the restraint. Any advice regarding would be much appreciated, I've attached a sample sketch of our geometry for clarity. If others are interested I could post more picts including est. results as I converge to anticipated solution.

Ben

After some trial and error, it is obvious that a wide range of results are possible depending upon application of load and stiffness of the restraint. Any advice regarding would be much appreciated, I've attached a sample sketch of our geometry for clarity. If others are interested I could post more picts including est. results as I converge to anticipated solution.

Ben

Regarding your boundary conditions (restraints). You should expect to see higher stresses if you model your restraints as perfectly rigid. This is true for areas closest to the restrained areas. As you get further away from your restrained areas, the way you model your restraint has less impact. As a general rule, locations greater than 3 characteristic lengths away are not siginificantly impacted (St Venant's principle). If you model your actual restraint (a floor) such as I think your beam is supposed to represent, then I would imagine your stress/strain values would be actually closer to reality provided the way you modeled your forces closely matches reality and that you structured your mesh suitably. You could always take the safer approach if you are unsure and make design decisions based on a rigid restraint, but this might lead to un-needed material use.