Gravity

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Gravity

The purpose of Gravity Gravity move is to apply the effects of gravity to individual parts or assemblies while the part/assembly is fully constrained. Specific modeling points are displaced due to their link to mesh nodes on which the gravity effect was applied. A Mass Matrix file is used to apply the gravity effect. Once gravity is added to the model and Nominal Build is executed, the nominal locations of the points in the model will see the effects of applied gravity force.

 

This move requires a mesh file and mass matrix loaded for the object part.

 

Gravity move applies nodal force on 3DCS points. The applied load depends on the number of ASETs and the linking distance between 3DCS points and mesh nodes. Therefore when it calculates the displacement, the equations used may produce different results if the number of 3DCS points is too small and/or the linking distance is too large.

In general, if you apply gravity on two models with the same fine FEA mesh and one has a few points while the other has many points, but both have good linking distances (zero distance), they should have similar results.

 

 

Procedure

•Open StiffGen, add the part, select appropriate FEA Tool and check the Mass Matrix box to generate the Mass Matrix file. Close StiffGen.

•Open the Load FEA Data move and load the mass matrix for the compliant parts, along with the mesh and stiffness matrix.

•Select the Gravity Compliant Gravity Move and select the assembly to create the move in. This move must be at a product level, at least one level above the part, after the Initialization move.

•Add parts using the [+] in the Parts Subject to Gravity field.

•Set the direction vector.

•Click OK to save and close the dialog.

 

 

MC-NX-Creo-SW_Gravity Dialog

hmtoggle_arrow1 Parameters

 

•Name: The move name must be unique to the model.

•Description: This is an optional explanation of what the move does.

•Help: The Help button is context sensitive; it will open the Help Manual at required topic page.

•Smoothing: Check the box to turn on RSM Smoothing.

•Parts Subject to Gravity: The 'plus' button allows adding the part(s) to which the gravity effect will be applied. They can be removed using the 'minus' button.

•Gravity Direction: Specify a direction in which the gravity will be applied. The Type-In is the only option available and is defaulted to (0,0,1) as specified in Preferences. If gravity needs to be applied in a different direction, the new values can be typed in.

•Summary: Shows move information in Notepad.

 

 

hmtoggle_arrow1 Outputs

 

•The result of this routine will be the deformed object part due to gravity

•This is a permanent deformation which propagates to other feature points on the object part.

 

 

 

Notes:

•Nominal Build must be performed before the this move is executed.

•Part must be fully constrained before applying gravity.