Normals for surface

Altair Forum User

Hello ,

 

I would like to know whether there will be normals/orientation for a surface as we have for elements in HM-12.

 

Thanks,

Abhijith 

tinh

Sure, there is

surface normal is very important when you extract middle surface or offset a surface

you can display / reverse surface normal in panel surface edit/offset

Altair Forum User

Thanks,

 

Usually when we locally alter the mesh ,the orientation/normals of elements change at few places.

 

In ANSA i have learnt recently that if the surface orientation is same the elements orientation does not change even if changes are made to the mesh locally.

 

do we have an option in HM as well. 

tinh

Hello

I am not sure how you change elements locally, if you create element by F6/create then normal is possible different

Anyway you should unify normals before exporting model

Altair Forum User

Well i meant to say i delete some elements near the hole/washer region or i go for ruled option and complete the mesh.

 

at these times few elements orientation would have changed. then i need to change the normals manually.

 

My question was ......in ANSA once the normals of the surface is fixed whatever changes( elements for example) we make , the normals of elements doesnt change it adheres to the surface on which the element changes were made.

 

but in HM its not tat case.

tinh

Yes, it is

if you remesh the elements by F12/elems then normals may not change

but if you modify the mesh by ruled/drag/spin/... then these action is not related to original surface so elements normal no longer specified by surface normal

so it is different from ansa perhaps

Altair Forum User

Yes, in ANSA whatever may be the changes w.r.t elements made ,  the normals of elements doesnt change coz the it adheres to orientation/normals made to the surface on which the elements are lying

 

Thanks that answers my query .

Altair Forum User

I created a mesh and adjusted normal's in same color. So now in my modal the normal vector is towards Z-axis.

So what will be the difference If I applied load in Z-axis and If i applied load in -Z-axis?

Altair Forum User

Altair Forum User said:

I created a mesh and adjusted normal's in same color. So now in my modal the normal vector is towards Z-axis.

So what will be the difference If I applied load in Z-axis and If i applied load in -Z-axis?

 

For shell elements, the modification of element normal has an impact on pressure applied on this element.

If your load is nodal forces, element normal does not have any impact on it.