Difference between grid and mesh 1

[salukice]

Hi,

I am currently being trained on the job in FEA and ran into a problem.

I was wondering what the difference between the grid that you set when setting up the analysis and the mesh. I always thought the mesh determined the nodes that the values were calculated at but was told here that the grid affects the number of values that are calculated. I was hoping someone could tell me what the difference is between the grid and the mesh.

THANK YOU for your help in advance!

 

[BlasMolero]

Dear Salukice,
Grid is the name of the node we use in Nastran, and mesh denotes both nodes & elements. Then the full finite element model is composed by the mesh (nodes & elements), material properties, loads & boundary conditions.
Best regards,
Blas.

 

[rb1957]

it sounds like you're using FeMap ... FeMap creates a mesh first, which sort of lays out the elements (and grids/nodes), then you put the elements onto the mesh.

 

[kellnerp]

Since you are starting out I'll give this explanation.

The term GRID is, as Blas stated, is synonymous with the term node.

In a typical finite element program a body is broken down into small areas or volumes. These small areas or volumes together are called a mesh.

A mesh is made up of elements and an element is designed so that it can be solved for various quantities important to the problem at hand.

Elements connect at nodes which are located at the element corners and perhaps along the edges and adjacent faces of the elements.

Typically the solution will be accurate for displacements at the nodes/GRIDS and perhaps not so accurate everywhere else on the element. By judiciously reducing the size of the elements one can make a model converge on the correct answer.

The number of degrees of freedom at a node depends on the element type. A 2D shell element will have all six degrees of freedom at a node. A 3D solid element will have only 3 dof per node. A 3D beam element will have 6 dof per node.

TOP
CSWP, BSSE

http://www.engtran.com

http://www.niswug.org

"Node news is good news."

 

[salukice]

Thanks for the help guys....I think I have a better understanding of the difference between the two.