Is the tank just sitting on the supports or is it welded to the supports?nIf it is just sitting on the supports, then use Frictional Contact.nIf it is welded to the supports, then use Bonded Contact.nA welded interface will create higher stresses than frictional contact.nFrictional contact will turn the model into a nonlinear solution and it will be more difficult to get the solution to converge.n