Ram Series manual
Data->Constraints
In this condition, the local axes have no relationship with the beam local axes defined in the properties section. The GLOBAL option means to prescribe related to the global axes of the problem. Local axes are used to prescribe the displacement or rotation in a direction not coincident with any of the global axes. The values part of the condition is used to prescribe a fixed amount of displacement or rotation. Default units are meters for the X, Y and Z displacements and radians for the prescribed rotations. X Constraint, Y Constraint and Z Constraint mean the displacements along the axes. Theta x Constraint, theta y constraints and theta z constraints mean the rotations around the axes. Signs are as follows (right hand rule):
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This condition can be applied to either points, lines or in the solid analysis, to surfaces.
Note: 3D solids have only three degrees of freedom: displacements in X, Y and Z.
The elastic constraints are similar to the constraints but instead of prescribing the displacement or rotation of a point, an elastic spring is attached to that node for each prescribed degree of freedom. The first three constraints: X-constraint, Y-constraint and Z-constraint are the prescriptions for the three displacements. If any is set, a value must be given that represents the stiffness of that spring. The last three constraints: theta-X-constraint, theta-Y-constraint, theta-Z-constraint, are prescriptions for the three rotations
This condition can be applied to either:
It is possible to use a combination of normal and elastic constraints for the same point. The only condition is that every degree of freedom must have prescribed only a displacement or an elastic movement.
This constraint can be used in the analysis of foundations and iteractions with the ground and terrain.
All nodes that have this condition assigned will permit a free rotation between all the beams that are joined in that node. The rotation is free in both, the Y' and Z' directions. Note that the rotules are only applicable to beams and not to shells and solids.
This is a condition similar to the last one, but it is assigned to the lines that define the beam. It is possible to define if only the initial node of the beam or the end node of the beam or both of them are rotules.
Note 1: Be careful to mesh more than one beam element per line. Every beam element will have its own rotules.
Note 2: To know which point of the line is the beginning and which one is the end, use Utilities->Draw normals->Lines and select the line.