non evenly distributed load on solid?

[cad2blender]

I have this solid model of a wing using solid elements and I would like to apply a linear distributed load and eventually a non linear load extending from root to the tip of the wing. I have successfully applied an evenly distributed load from the root to the tip. I simply selected Model-->Load-->On Surface. The root is fixed and the tip is free to translate and rotate. How would I go about doing this?

 

[rb1957]

1) read the manual ... there are many ways to apply load to a surface, not just constant pressure.

2) apply load to the elements meshed onto the surface, constant pressure or linear varying ... i don't think there's much point in doing anything else on an element, 'cause i think that's pretty much all the elements are coded for.

 

[dwallace1971]

Why would you create a solid model of a wing?

 

[cad2blender]

The reason I want to model it as a solid is because I imported a parasolid model of the wing that I made in solidworks. I would like to import it, mesh it and run some stress analysis on the structure.

 

[dwallace1971]

Any solid model of a wing detailed enough for reliable stress analysis would be unnecessarily huge and a computational nightmare.
Ideally, you would create a loads model of axial and shear elements, then create detailed models only of the areas of interest.

Somewhere around here I have good guide for modeling aircraft structure. I'll see if I can dig it up.

 

[cad2blender]

The thing is that since my airplane wing is a bit more complex. It has a serrated leading edge and an airfoil (not a flat plate) So I thought the only way was to model it as a solid and not a surface with plate elements. Another problem I ran to was since the plate elements need a thickness and my wing is not a constant thickness I just used a solid element instead. Is this a reasonable method of modeling the wing? After reading the manual I was able to figure out the distributed loading.

 

[rb1957]

i assumed you were dealing with a model wing, or maybe using something other than Al (or metal) ... maybe some plastic.

i think any "real" wing would need skins to take the bending stresses, maybe Al sheet, maybe some plies of Glass fiber. the body of the wing could be some sort of solid (foam?) but most wings use the internal volume.

i think you can extract the surfaces from your solid, mesh them with plate elements (thickness sized to suit the stresses), then project this mesh onto the solid to mesh the solid (if that's the way you want to go.

as noted above, a solid wing is very unusual !

 

[cad2blender]

Yes it's very unusual, it's a solid model that will be printed on a 3d printer, so it will be a solid wing. That's the reason I used solid elements to mesh it. There won't be any spars, skin or anything like that.

 

[rb1957]

so it is some sort of model wing ? (not that that is a bad thing, just helps us understand the problem better)

 

[dwallace1971]

My mistake. I assumed you were modeling an actual wing (not a trivial undertaking). I found the document on modeling aircraft structure if you're interested.

 

[cad2blender]

Yes I am interested in the document, it might help me out in future projects

 

[dwallace1971]

Here ya go. Enjoy!

 

[cad2blender]

for some reason that link is not working, I download the linked file and its a blank page

 

[rb1957]

maybe it is working ! :-D

 

[dwallace1971]

It is a fairly large file. I'll see if I can find a link online.

 

[dwallace1971]

Just Google "rules for modelling structures", including the spelling error. It should be at the top of the results. If you spell modeling correctly, it won't be.

rb1957, you wouldn't happen to be a graduate of Auburn University, would you?

 

[rb1957]

hell no ! ... UNSW ...

 

[ThomasH]

Just as info.

The download worked fine for me.

Regards

Thomas

 

[rb1957]

link worked for me too ...