Node fitting for forces with projection on to mesh from a curve

General Questions
1

Hi All, It is complicated question to explain.

I want to use specialy defined curve to define my loads on mesh. In prepomax i am not able to import curve, instead of importing curve i imported a surface to obtain special nodes that i want to apply force:

The 3D geometry is below: The curve that i want the nodes from its edges is defined near the circular cutout.

{F98CABF3-EA34-4308-9E29-12F93B957454}
{F98CABF3-EA34-4308-9E29-12F93B957454}1534×897 60.7 KB

The problem is when I want to select the nodes on the mesh it automatically applies the force to the surface not to 3D model as normal.

Are there any option to project nodes on the surfaces over the 3D nodes.

Kind Regards

Deniz

2

You can create a node set first:

image
image1263×676 156 KB

or select an edge directly, but not for the Surface Traction load (it needs faces) - you could use the Concentrated Force load instead:

image
image1250×675 163 KB

Just make sure that you divide the total force by the number of nodes - the specified force is applied to each node.

3

The problem in here is the curve that i mention is not the curve of the mesh, it is another surface to mention the problem,

image
image1184×704 174 KB

I need the reference from that curve to apply the force, in your representation the selection of circular shape is already in the mesh, as you can see my mesh has no circularity in order.
With nodes set i am only able to select the nodes on the meshes.
{2149AAD3-C425-4931-910E-44ACE103FEDD}
{2149AAD3-C425-4931-910E-44ACE103FEDD}1776×546 87.5 KB

basically curve is this

{93E42697-7105-420B-B7EC-953F893D47B8}
{93E42697-7105-420B-B7EC-953F893D47B8}2339×1036 207 KB

4

So you don’t have the nodes there ? If you partition the surface with a closed curve in CAD software (e.g. in FreeCAD using the Boolean fragments tool) then the mesh will adapt to it. The shape can be arbitrary.

Alternatively, maybe you could use distribution from a file - PrePoMax will interpolate the load values from points with coordinates and load magnitudes specified in a text file.

1 Like
5

I have the 3D geometry, Do you want me to divide in different 3D geometries?

6

There is a tool to split meshes with surfaces: https://youtu.be/IVUpfZd702g?is=_G2eug2OU9_d0wU9

But I would just project the curve and split the surface with it in CAD.

1 Like
7

I mean face partitioning - dividing the surfaces of CAD geometries into subregions. It’s easily doable with a sketch.

https://wiki.freecad.org/FEM_Geometry_Preparation_and_Meshing#Geometry_partitioning

1 Like
8

Thank you very much again. It fixed my problem, i basically split the surface with the reference curve in rhino and join them together <3

9

Yeah, that should be possible in a similar way in most CAD software. Face and volume partitioning is very helpful for FEM to apply loads or generate better meshes.