Displacement

The displacement restriction can be set for any type of geometric entity.

Creating or changing a move is done as follows:

On the Command Bar, select Mode - Boundary Conditions.
Select Entity - Displacement.
Using graphical user interface elements specify the identifier (ID) or the name of the set of boundary conditions, specify entity that are subject to restrictions, determine the degrees freedoms and the magnitude of restrictions.
Click Apply.

The corresponding commands entered in the command prompt window, have the form:

create displacement [ID] [name <'name'>] [{add | on} {nodeset | volume | surface | curve | vertex | hex | tet | face | tri | edge | node} <entity_list>] [DOF {all | {[1][2][3][4][5][6]}} fix <value>] [smallestCombine | average | largestCombine | OVERWRITE]

modify displacement {ID_list | 'name'|all} [name <'name'>] [{add | remove} {nodeset | volume | surface | curve | vertex | hex | tet | face | tri | edge | node} <entity_list>] [DOF {all | {[1][2][3][4][5][6]}} {fix <value> | free}] [smallestCombine | average | largestCombine | OVERWRITE]

The parameters (options) of these commands are described below.

Degrees of freedom

The key parameter of each of the above commands is index of restricted degrees of freedom DIV (degree of freedom). Using its all value, it is specified, that the restrictions imposed apply to all six degrees of freedom node. These degrees of freedom are given in Table 1.

Table 1 - Degrees of freedom

Indicator degrees of freedom	Physical meaning
1	Moving along the x-axis
2	Moving along the y axis
3	Moving along the z axis
4	Rotation around the x axis
5	Rotation around the y axis
6	Rotation around the z axis

Degrees of freedom can be specified in the command in any order. Value strings 1 2 3 4 5 6, 2 6 1 4 3 5 and all will lead to the same result.

Nature of restrictions

To describe the nature of the restrictions imposed , the following are used parameters fix and free. When specifying fix without any value defined (using DOF) degrees of freedom are rigidly fixed. In case of entering fix <value> there is a restriction corresponding to the entered value. It is possible to enter the value is 0; it is equivalent to specifying fix without a value. If the user wants to remove restrictions, then you can use the parameter free.

Combinations of constraints

Options smallestCombine, average and largestCombine are used to get a combination restrictions. They are applicable only for changing (modifying) existing ones boundary conditions.

The smallestCombine option provides a comparison existing constraints with the current values entered on the command line. According to the results of the comparison, the smallest value is taken and used further as an effective boundary condition.

The average option allows you to determine the average the value of the constraint, based on the existing boundary condition and the current the value specified on the command line.

The largestCombine option gives the result in the form of the largest value of the constraint from the existing boundary condition and the input value.

If none of these options is specified, then it is used the default combination is OVERWRITE, in which the last specified on the command line becomes the valid boundary condition.