Cantilever shell

Hi! I am making a shell with the command ¨Shell Var¨, in this case I made a shell with only one area of support, then it is like a cantilever.

In a cantilever frequently you should make higher the sector near to the support, because the moment is bigger.

But when I increase the high in the opposite extreme the displacements decreases, I think that this should increase the displacements because I am increasing the mass (Kg).

There are any issue in the model?

Best

Patricio

Attachments:

Shell 250.jpg, 1.1 MB
Shell 25.jpg, 1016 KB
Shell 25-250.gh, 34 KB

Replies to This Discussion

Permalink Reply by Karamba3D on October 7, 2018 at 1:43pm

Dear Llordella Patricio,

I think the result you get is possible: The weight of the structure increases linearly with the cross section height at the tip, the bending resistance however increases with height to the power of three.

Did you try an equivalent cantilever generated from beam elements?

Best,

Clemens

Permalink Reply by Llordella Patricio on October 7, 2018 at 5:16pm

Dear Clemens, thanks

Yes I tried it with a cantilever generated from beams elements, I send you screamshots.

Best

Patricio

Permalink Reply by Llordella Patricio on October 8, 2018 at 1:07pm

Dear Clemens,

You are right, I calculated the shell structure with f = 5/384 x q x l4 / E x J , and I could check it.

I tried with 2 shells:

1- Shell const 50 cm

2- Shell Var from 50 to 150cm

Then I calculated the height with 60cm because I take the first 50 cm of shell like support, as mesh refine is 50cm. (Pic 1)

However when I tried it with beam elements the output was different. Why? Because when I make the beam I use segments with height constant, then I have a first segment near support with 50 cm. In this situation I only modify the weight, because the support height will be just 50 cm.

In conclusion I think that it is directly related with the segment refine and the material stiffness in the support.

PS: I am working with nature structures, so I had to create a Shell Var.