Function
- Enter specified (forced) nodal displacements, or modify or delete previously entered specified (forced) displacements.
Call
From the main menu, select [Load] tab > [Type : Static Loads] > [Static Loads] group > [Specified Disp.]
Input
Specified Displacements of Supports dialog box
Load Case Name
Assign the load case name. Click the ... button to the right to enter additional load cases, and modify or delete existing load cases.
Load Group Name
Select the desire Load Group that will include the entered Specified Displacements of Supports data. Select "Default", if a Group assignment is unnecessary. Click the ... button to the right to add, modify or delete Load Groups.
Options
Add : To enter new or additional specified displacements at selected nodes assigned with constraints
Replace : To replace previously entered specified displacements at selected nodes assigned with constraints
Delete : To delete previously entered specified displacements at selected nodes assigned with constraints
Displacements (Local Direction)
Enter specified displacements with respect to the GCS or nodal local coordinate system.
If the nodal local coordinate system has already been defined for specific nodes the data for the nodes are entered with respect to the NCS.
Dx : GCS or nodal local x-direction component of the specified displacement
Dy : GCS or nodal local y-direction component of the specified displacement
Dz : GCS or nodal local z-direction component of the specified displacement
Rx : Specified rotation component about GCS or NCS X-axis
Ry : Specified rotation component about GCS or NCS Y-axis
Rz : Specified rotation component about GCS or NCS Z-axis
The specified displacements are considered load cases in midas Civil. Thus, the specified displacements can be combined with other load cases. Note the following when generating load combinations in a model applied with specified displacements. If specified displacements are assigned to a node, the relevant degrees of freedom of the node are automatically constrained.
Therefore, the nodes assigned with specified displacements behave like Support even for other load cases that do not contain specified displacements. In other words, the function serves to define "Specified Displacements of Supports" in midas Civil.
The load conditions that allow for forced displacements include not only Dead and Erection conditions but also Tendon/Creep/Shrinkage, which are treated as a single load condition. If forced displacements are applied to the final stage's Dead Load, the final displacement, including the displacements from the previous stages of Dead/Tendon/Creep/Shrinkage, becomes the forced displacement value.
Dead | -0.1 |
---|---|
Creep | -0.1 |
Shrinkage | -0.1 |
Tendon | -0.1 |
For example, if the previous stage displacement is considered as joint displacement and the forced displacement value of 0.1 is applied to the Dead condition, to achieve a final displacement of 0.1 for Dead + Creep + Shrinkage + Tendon, a forced displacement of 0.5 is applied to the Dead condition.
Revision of Civil 2017 (v3.1)
In the previous version, when settlement load cases or specified displacement loads were assigned to some nodes, the nodes behaved like fixed support even for other load cases that did not contain specified displacements. In Civil 2017 (v3.1), only the nodes to which specified displacement load case or settlement load case are applied will behave like fixed support.