Why do I get a section about 'Design Volume Fraction' in my out file

Leon_21463

Hey Everybody,

I started working with hypermesh about a few months ago. I now notices that my .out file has changed a little bit ever since.

For a modal analysis, before the 'Subcase  Mode  Frequency...' Section there is a new block, that has never been printed before.

I looks like this:

Design Volume Fraction              =  1.00000E+00   Mass     =  1.61845E-02
Discreteness Index                  =         1.00
 
Density     %
-------------
0.0-0.1   0.0   
0.1-0.2   0.0   
0.2-0.3   0.0   
0.3-0.4   0.0   
0.4-0.5   0.0   
0.5-0.6   0.0   
0.6-0.7   0.0   
0.7-0.8   0.0   
0.8-0.9   0.0   
0.9-1.0 100.0

I assume this has something to do with optimization settings, however, I only performed a modal analysis without any optimization settings.I also checked the 'Optimization View' in the model tab but the only thing defined here is my load case. I checked with other models and this seems to be normal. I didn't define any other optimization parameter.

Usually this block should look like this:

Volume                              =  1.13360E+06   Mass     =  1.63998E-02

 

I don't know what setting or modification on my model has let to this changes in the output and I'm curious to get some ideas on why this cold be happening.

Thanks for any suggestion!

Best regards

Leon

Adriano A. Koga

this is indeed related to topology optimization output. It is a histogram of the element densities during an optimization run.

I don't know why is this written in a simple analysis, run.

But anyway, is this causing any trouble for you? just curious.

Leon_21463

Hey Adriano,

I think it should not cause any problems since the density is still set to 100%. But I'm currently comparing if this does make any difference.

My latest assumption is, that there might be a connection to an geometry import from solidworks... maybe an optimization has been performed on one part prior to my analysis in hypermesh but this is just a random guess...

I will let you know if that has any impact on the resuls

Best wishes

 

Adriano A. Koga

Leon_21463 said:

Hey Adriano,

I think it should not cause any problems since the density is still set to 100%. But I'm currently comparing if this does make any difference.

My latest assumption is, that there might be a connection to an geometry import from solidworks... maybe an optimization has been performed on one part prior to my analysis in hypermesh but this is just a random guess...

I will let you know if that has any impact on the resuls

Best wishes

 

the solver doesn't know of any previous connection or evaluation from SW.

Maybe take a further look into your .out file, and check if nothing else about optimization is mentioned.

 

Leon_21463

Adriano A. Koga_21884 said:

the solver doesn't know of any previous connection or evaluation from SW.

Maybe take a further look into your .out file, and check if nothing else about optimization is mentioned.

 

I will do that again!

I even exported my model as a solver deck and deleted the whole 'Design Variable' block. However, when I then re-import this solver deck I suddenly get a Design Variable in my Model Tree although I never defined one (at least not on purpose) or even had one in my Model Tree previously. That seems really strange to me.

Leon_21463

Adriano A. Koga_21884 said:

this is indeed related to topology optimization output. It is a histogram of the element densities during an optimization run.

I don't know why is this written in a simple analysis, run.

But anyway, is this causing any trouble for you? just curious.

Hey Adriano,

just for your information. I did not cause any further problems. There was just the slightly different block in the output file.

I found, that I had messed up something in my properties. I accidentally assigned a parameter that seemed to be connected to optimization. It didn't have any impact on the results just the mentioned format changes.

After I corrected the property, the 'Density Volume Fraction' disapperared.