Vessel Analysis

[gamack]

Hello everyone,


I need help to analyse (mechanica) the pressure exerted on a square vessel filled with water.


I have never tried this before in WF2.


Can anyone help?
Edited by: gamack

 

[Remmerv]

Hi Gamack,


Two tips:
1. For a square vessel I would expect the deformations to be considerable so keep in mind that you may need the large deformations option which will restrict you to solid elements (and a lot of them if the wall is thin). Otherwise you could start with midplane compression and shell elements.
2. For the water you will need a pressure as function of coordinates in order to get the pressure of zero at the top and the full watercolumm at the bottom.


The rest is basic MECHANICA.


-Victor

 

[ndk]

Hi gamack!


Try this link on vessel stress analysis.Unfortunately,this tutorial is done in Pro/mech independent mode. Anyway, I thougt that it's helpful for you. If neccessary, you can redo it in integrated mode.


http://sungear.mame.mu.oz.au/eng_design/mstruct/main.html


NDK

 

[napoleonm]

Hello Gamac...


Can you tell me if yourdesign need to be under a specific pressure vessel code as ASME 8 div 1 or 2, Bristh standard or any in particular?..... depending in that the way how you are going to perform your FEA will save you computer running time and stress interpretation (the last one is the more important).


let me know.

 

[gamack]

Hello Napoleonm,


This is a project that I am trying to solve for my own person learning.


Please note that I have never done a tank analysis in mechanica.


I am looking for some guidance on how to setup the analysis.


I have played with some variables in mechanica but seem to be doing something wrong.


I have not done the tutorial that NDK has posted, looks good though.

 

[napoleonm]

Could you send me your model, let me have a loock in it.


Becasue it is not a "pressurized vessel" you will need a pressure as function of coordinates in order to get the pressure of zero at the top and the full watercolumm at the bottom.


Rectangular vessels, needsbigges thickness than cylindrical or conical vessels (under internal pressure),this isdue to the high bending stress, cylindrical and sphericals are the ones than produce the best distribution of membrane stress across the wall thickness and the bending strees are the minimal....you need to keep it in main.


so, in pressure vessels codes, you need to evaluate membrane and bending stress across the wall section, its combination cannot be more than the allowable stress given by your code.


Now, a 3D model in pro/e that can be idealized as a "SHELL" model, it the best direction to do a stress analysis for pressure vessels; this is due the facility of membrane and bending stress that you can get from the results.


Otherwise if your model it too complicated and needs to be done under a solid element idealization, you need to evaluate the stress (membrane and bending) across the wall thickness of your vessel in the criticals points and this is a little bit more complicated (again that depends of your model).


the link that NDK gave you it a good start point.

 

[ndk]

How about the size of the vessel? Nevershould U use FEAwith solid elements to analyse thin-walled-models. The number of elements is extremely large and possibly your PC crashed. Shell idealization is much more appropriate with high accuracy and low time spent.