nastran nx femap - mass point

[Nevenick]

Dear Sir,

I would like to put a mass point above a surface.
What is the procedure for making it ?

Best regards,

 

[Naffoussi]

Hi,


Use a RBE3 element; connect independent nodes (only translational DOF checked) to where you mass is attached to the surface.
Use a CONM2 mass element at the CoG location and create a property with the right mass value.

That's all.

Seif Eddine Naffoussi, Stress Engineer

http://www.Innovamech.com

33650 Martillac û France

 

[Nevenick]

Dear Sir,

Thank you for your answer.

I am new NASTRAN user and I attempt to recreate what you propose, but I don't success.

I try to making it for the two points:
-- "Use a RBE3 element; connect independent nodes (only translational DOF checked) to where you mass is attached to the surface."

Is it :
* Model > Element > TYPE = RIGID" > RBE3 (interpolation) > NODES > METHOD = BY SURFACE > UM DOF
TX,TY,TZ activate, rotations deactivate for “Dependent, Independat and in Nodes” ?

-- "Use a CONM2 mass element at the CoG location and create a property with the right mass value."

Is it :
* Geometry - Point - In surface - Ok - Cancel
* Mesh - Geometry - Point - Property (choose red symbol) - Mass (value ex : 300) and OK ?

But I don't obtain something like the pic enclosed.


Reference used:

The picture is extract from :

http://www.sestructures.com/foundat...ns-finite-element/38-foundations-rbe2-vs-rbe3

Other reference:

http://www.eng-tips.com/viewthread.cfm?qid=310645

http://www.predictiveengineering.co...l_connection_elements-mpc_and_cbush_rev-1.pdf

http://fr.scribd.com/doc/91829085/RBE-2-n-RBE-3#scribd

https://docs.plm.automation.siemens...nastran/10/help/en_US/tdocExt/pdf/element.pdf

Glossary:
DOF: Degrees Of Freedom
RBE: Rigid Body Element
CONM: CONcentrated Mass Element
CoG ?