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Simulation Mechanical and Multiphysics

Contributor
Posts: 14
Registered: ‎02-07-2011

Volume Averaged Stresses in Simulation Mechanical

206 Views, 3 Replies
01-08-2013 10:49 AM

When trying to calculate volume averaged stresses, one can select "inquire results" and first: select nodes and then select elements which includes the nodes to get a volume averaged stress value. Is there a way to just select parts and or elements to get volume averaged stress values?

The wait times can be improved on a later release as a suggestion.

Best Regards...

Can

Can Ozcan
AKRO Engineering
can.ozcan@akroengineering.com | www.akroengineering.com
Distinguished Contributor
Posts: 141
Registered: ‎06-13-2012

Re: Volume Averaged Stresses in Simulation Mechanical

01-08-2013 10:05 PM in reply to: COzcan

Hi Can,

I think you can select the parts that you are interested with using Selection>Select>Parts and then right-click>Select Subentities>Nodes to select all the nodes in the part. Then, you can inquire the results via Current Results and use the Mean operation to compute the average stress. Depending on the number of nodes, this may take some time.

Regards

Ilyas

Contributor
Posts: 14
Registered: ‎02-07-2011

Re: Volume Averaged Stresses in Simulation Mechanical

01-09-2013 07:58 AM in reply to: ilyas

Hi Ilyas;

Thanks for the reply. However what I am looking for is the volume averaging, not the mean value. Mean is easy to calculate which is min plus max divided by 2. Volume averaging requires calculation of element volume and a summation over all selected elements.

Best...

Can

Can Ozcan
AKRO Engineering
can.ozcan@akroengineering.com | www.akroengineering.com
*Expert Elite*
Posts: 575
Registered: ‎08-30-2012

Re: Volume Averaged Stresses in Simulation Mechanical

01-09-2013 09:21 AM in reply to: COzcan

I suspect the "mean" that Ilyas is referring to is (sum of stress at all nodes)/(number of nodes) which is different than (maximum + minimum stress)/2. Naturally, this is still not the same as averaging based on the volume.

Some results can be averaged based on the volume or mass. If you open the "Results Inquire > Inquire > Current Results" window, select an element in the model, and if the results are shown (at the nodes on those elements), then you can get a volume weighted average. I know that temperature can be averaged based on the volume, but stress cannot.

Before you can get the volume weighted average, you need to run the "Analysis > Analysis > Weight and Center of Gravity" command. Then the "Inquire Results" dialog's "Summary" pull-down has the option "Mean weighted by volume".

Since the software will not do the calculation automatically, you could perform the calculation in a spreadsheet. First, display the "Results Contours > Other Results > Element Properties > Volume", select the elements of interest, inquire on those results, and "Save Values" to a .csv file. Then use "right-click > Select Subentities > Nodes" to get the nodes on the same elements, display the stress contour, inquire on those results, and "Save Values" to a .csv file. Then in a spreadsheet, you can create a lookup formula to put the volume of the element next to the stress at each node and perform the volume averaging calculation.

John Holtz, PE
Mechanical Engineer
Pittsburgh, PA

Simulation Mechanical user since Dec 1997