Specified Displacements of Supports

 

 

Enter specified (forced) nodal displacements, or modify or delete previously entered specified (forced) displacements.

 

 

 

From the Main Menu select Load > Static Load > Specified Disp.

 

 

Load Case Name

Assign the load case name. Click 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 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

Note

The specified displacements are considered as 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.
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.

Revision of Civil 2017 (v3.1)

In the previous version, when settlement load cases or specified displacement load 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.

 

 

Revision of Civil 2014 (v2.1)

Q1. Can you explain why the sum of reactions due to the ‘Specified Displacement’ load case in model file is not equal to zero. It is close to zero but not exactly. Does midas have any setting where the precision can be controlled by the user?

Q.2 I assigned a fixed support to the pier of my bridge model. To this fixed support, I specified a displacement of +0.5m (z- direction) in Construction Stage2. When I deactivated the specified displacement load case in CS3, I expected the support to come back to its initial position, i.e. the position before activating specified displacement. But after deactivating the specified displacement, the support didn't move and remained at z=0.5m. Why?