Displacement constraints

The four inferior points of the structure have a prescription in their movements in the three global directions X, Y and Z. Rotations in the points are not prescribed.

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. This is used in this case. 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. In this case, the prescribed displacements and rotations are all zero.

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):

 


This condition must be assigned to the four points in the inferior (minimum Z) part of the structure.