For static analysis, a structure needs to be supported in such a way that it can not fly around freely. In three dimensional space, a rigid body has six modes of movement or degrees of freedom (DOFs): three translations and three rotations (see fig. 220.127.116.11). Thus there need to be at least six support conditions in a structural model to fix it. When a model or parts of it are moveable, the “Analyze”-component either refuses to calculate or returns huge displacements. Should you encounter a problem like this plug your model into the “Eigen Modes”-component. It can detect the rigid body movements which cause the problem.