Results of an analysis are unexpected when using a remote force in Inventor Nastran

Autodesk Support

Oct 8, 2023

Products and versions covered

Issue:

The results of an analysis in Inventor Nastran are unexpected when using a remote force. This occurs when using Nastran In-CAD (versions 2019.2 and older) or Inventor Nastran (version 2020.0 and newer).

Causes:

The problem occurs when the remote force is applied to more than one surface.

  • In Nastran In-CAD 2019.2 and older, the reaction force and moment matches the remote force magnitude multiplied by the number of surfaces to which the load is applied. For a force of 10 applied to 6 surfaces, the total load and reaction force is 60, and the reaction moment is 60*the moment arm. The displacement and stress results agree with this load.
  • In Inventor Nastran 2020.0 and 2021, the reaction force matches the remote force magnitude. A remote force of 10 gives a total reaction of 10 regardless of the number of surfaces to which the load is applied. The reaction moment does not match the applied load. Therefore, the displacement and stress results do not agree with the remote force of 10.

Solution:

Change the definition of the Remote Force

  • In Nastran In-CAD 2019.2 and older, apply a magnitude of the remote force equal to the total load desired divided by the number of surfaces to which the load is applied. 
  • In Inventor Nastran 2020.0 and newer, apply the remote force to one surface only.


Use Rigid Body Connectors

Follow the steps:
  1. Go to Connectors from the Prepare tab.
  2. Select Rigid Body as a Type.
  3. Change Type of Rigid body on Interpolation.
  4. to apply the force at the required (distant) position to selected surfaces.
  5. In the Select Point choose a point to define the origin of the connector.
  6. Use Force as a load and attach it to the point (origin of the connector). 
Image_2021-03-10_14-07-13.png
 

Products:

Inventor Nastran;

Was this information helpful?

Need help? Ask the Autodesk Assistant!

The Assistant can help you find answers or contact an agent.

Ask the Assistant

What level of support do you have?

Different subscription plans provide distinct categories of support. Find out the level of support for your plan.

View levels of support