DOF dependence check

You can find and resolve double dependencies within your model using the DOF Dependence Check command.

Double dependencies occur when two rigid elements share a dependent node. If your model contains double-dependencies, the solver may not be able to correctly resolve the degrees of freedom in your model.

Double-dependent nodes in RBE2 (left) and RBE3 (right) elements.

Checking for double dependencies

You can use the DOF Dependence Check command to check the following elements within your model for double dependencies:

• RBAR

• RROD

• RBE2

• RBE3

• MPC

The DOF Dependence Check command displays a list containing information for each conflict found such as mesh names, element types, and labels of the elements involved, as well as node label and DOF at the conflicting node. In the Id column, each conflict is marked by an icon and a number.

DOF dependence check results

Resolve double dependencies

The DOF Dependence Check command allows you to resolve double dependencies by editing or deleting the elements that are connected to the node at which the conflict exists. When you edit an element, you can change the nodes that the element connects to or reverse the independent and dependent node selection. This ensures that the connected elements no longer share a dependent node.

(1) RBE2 element, (2) RBE2 element, (3) shared dependent node with conflict

When you edit or delete an element, the conflict's status in the Id column changes to . This indicates that the model needs to be rechecked to ensure that the conflict is resolved.

Edited elements that need to be rechecked

After you recheck your model, all resolved conflicts are removed from the list. Remaining unresolved conflicts are indicated by an icon in the Id column.

For more information on identifying and correcting double dependencies using the DOF Dependence Check command, see Identify and correct double dependencies.

Note:

Universal connection elements that you edit using the DOF Dependence Check command are locked to prevent overriding the edits you made.

If you want to override the edits you made, you can unlock the mesh by right-clicking in the Simulation Navigator and choosing Unlock .

Where do I find it?

Application	Pre/Post
Prerequisites	A FEM or assembly FEM file as the work part and displayed part
Command Finder	DOF Dependence Check

DOF dependence check, Simcenter 3D 2021.1 Series

© 2020 Siemens

window.mainLanguage="en_US"

window.delivId=""

window.projectId=""

MathJax.Hub.Config({ TeX: { extensions: ["autoload-all.js"] }, tex2jax: { displayMath: [ ] }, "SVG": { scale: 125 } });