Cylinder mesh dependent solution ??

[Anonymous]

Hi,

I'm modelling a 42m diameter shell cylinder loaded with internal liquid pressure and I'm experiencing problems with explanation of the influence of the mesh on the results.

So here is the problem - I prepared the model and created the mesh that was globally regular with increased density near foundation level. Firstly I noticed, that there is visual graphical pattern of results near foundation, which was more less coherent with the meshing. So I thought - what if I increased the density of the mesh above the foundation area ? So I did it and I don't understand what's happening.

My doubts are as follows:

1) the HMH stress level increased, why ? Let's disregard the differences described below.

2) the stress level inside the rectangular finite elements (of the same size proportion and load) is more less regular on the bigger FE, while it's irregular inside small FE, why ?

3) the integral from the panel cross sections significantly differs, what suggests, that the stress level is uneven and not distributed regularly, while the load is axially symetrical, why ?

I'd appreciate any help.

Thanks in advance,

Tomek

[Artur.Kosakowski · Accepted solution]

The original shape of meshing followed the shape of the circle whereas manual mesh refinement created smaller elements being in one plane rather than forming n arch. IMHO the better solution would be to increase the number of divisions along the circle for the entire tank instead. 

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