creating cylindrical coordinate system and selecting nodes in an area within certain angular limits and applying pressure as an

Altair Forum User

Hi guys,

I am a PG student in Mechanical engineering and I am doing a project on automobile alloy wheel and I want to do structural analysis on it.

In the static analysis the pressure load is to be applied as cosine function on the bead seats of the rim through an angle of 80 degrees. So, first I have to create a cylindrical coordinate system and then nodes within the angular limits is to be selected. I don't know how to do it in Hypermesh.

I tried to export the model in Ansys. But I could not apply pressure load on the model imported from Hypermesh in Ansys.

Please help me..

tinh

Hi,

To define cylindrical system, enter panel Analysis/system, switch 'rectangular' to 'cylindrical'

Altair Forum User

Hi..

Thanks for the help..

I could create the cylindrical coordinate system, but I cannot select the nodes between the angular limits on the surface.

Please tell me how to do that..

Vishnu

tinh

Hi Vishnu

just draw a line, copy it and rotate 80deg then select nodes between that two lines

Altair Forum User

Hi,

I could select the required nodes. Thank you so much..

Now, my problem is to apply pressure on these nodes as an equation. The pressure is to be applied in cylindrical co-ordinate system because its magnitude varies with the angle.

The equation is 'pressure, p= 2.5*{cos(2.25*t)}, where t- angular co-ordinate.'

Please help me to create the equation and to apply it.

Regards,

Vishnu

tinh

Hi Vishnu

on panel Analysis/pressure, change 'magnitude' to 'equation' and type in your equation:

2.5*cos(2.25*y)

select 'system' point to the cylindrical system

pressure is applied to elems, so select elems attached to the nodes

Altair Forum User

Hi Tinh,

I saw the 'equation' option in the analysis panel which only comes for 'elements'.

But my problem is to select the elements attached to the nodes.

How can I select 3D elements attached to required nodes or surfaces?

I also tried the path 'elements--> by geometry--> surfaces--> by face-->(selected required surfaces)'. But it didn't work.

Please help me..

Regards,

Vishnu

tinh

Hi,

Are there too many elements need be selected? if manual selection is tedious with you, you can:

- Shift F5, switch to 'find attached' to find elements attached to the nodes, save found elems

- On pressure panel, select elems by 'retrieve'

Altair Forum User

Hi Tinh,

 

Thank you so much for the help.

 

I have completed the structural analysis successfully.  

 

Regards,

Vishnu.V.A

Altair Forum User

Hi,

 

I am having a similar problem. I have an arbitrary shape that I'd like to select nodes on based on angle. Could someone elaborate on how to do this? I've set up a cylindrical coordinate system and want to select nodes by r. Thanks for the help.

 

-Becca

tinh

hi,

when you selecting nodes, hold down shift and press mouse button from hm11 there is an option for select entities inside/outside of a circle

this may help you in your case

Altair Forum User

Thank you for your quick response. Your suggest doesn't seem to work for my application, it just selects nodes in a circle. I'd like to be able to input an angle r from the cylindrical system, and have hypermesh select all nodes at that angle from the origin. Is this possible?

tinh

yeas, ofcourse it is possible, but not available. just make sure you assign cyl-coodinate system to the nodes then you can select them by local x, y, z ( phi, r, z)

please refer to guiding of *createmark tcl modify command, it's helpful to your application

Altair Forum User

@tinh

Hi

I am able to create the coordinate system. How do I get the output in the new system?

Is the best method to choose axis in hyperview?

 

Altair Forum User

Hi mramakri,

 

Change the Resolved in option to User system and select the system you created, to get the output in the new system as shown in the below image.

 

Thank you

Altair Forum User

Thanks @Premanand Suryavanshi

How do I relate the x,y,z in result type to the user system. In my case, its cylindrical. Is there a way to figure out the the corelation between x,y,z and r,t,z?

Altair Forum User

Hi mramakri,

 

The results along X-direction relates to r-co-ordinate, Y-direction to t-co-ordinate and Z to z

 

 

Thank you

seyilmaz

Altair Forum User said:

Hi Vishnu

just draw a line, copy it and rotate 80deg then select nodes between that two lines

 

Hello Tinh,

 

How do I make selection of nodes between lines (surfaces for my case). Thank you.

 

Regards, 

 

Emre