Analyzing time consumotion in 2015 version

[Anonymous]

Recently i`ve shift to simulation 2015 version. i have tried to perform linear static stress analysis on a beam. It takes like ages to do the analysis.

does anyone know how to overcome this issue ?

Thanks in advance

[zhuangs]

It might be related to Simulation Job Manager.  You can try to restart the machine to see whether it works.

-Shoubing

[Anonymous]

i have tried the same modle as a new file .. but still same... in 2014 modle it didnt take time at all .. do i need to reinstall 2014 again ?

[zhuangs]

In both of the two figures, the material for each part is not completely defined.  You can check whether some material property is not defined.

-Shoubing

[Anonymous]

Well I took screenshot before analysis.. i have assigned the material and all constrains before analysis otherwise it wount run ...

[zhuangs]

We can investigate the issue like this:

(1) "Check the model" first.

(2) Run 'arun4 ds -run'  from the command line to see it works.

If we can run from the command line, Simulation job manager results in the issue in your manchine.

-Shoubing

[AstroJohnPE]

Since the user is running a static stress analysis, the command line should be "srunx ds -run".

Also, you would need to set your path in the command (DOS) window to the location of the file "ds.asd" which is in the directory "my model name.ds_data\design scenario number" where the text in bold needs to be substituted with the appropriate text for your model.

[Anonymous]

Sorry for my late respond. well i have found whats the problem.

I use a MES with nonlinear Material Models for analysis and when i ran simulation it failed. I have used the concrete as material but when i choose the iron as material the simulation is successful.

however when in Element Definition i select elastic>isotropic the simulation runs, but when it comes for plastic the simulation fails.

anyone knows whether the properties of concrete material should be change in order to run simulation for plastic analysis ?

Thanks all for ur help and responds

[zhuangs]

For concrete (High Strength) material in structure, it cannot stand too large plastic deformation.  When you use plasticity material model for concrete (High Strength), you can find that the "Yiled strength" and "Hardening modulus" are not defined in Material Library.  If you do want to need plastic deformation for concrete (High Strength) material, you need to defined the "Yiled strength" and "Hardening modulus".

-Shoubing

[Anonymous]

Thank you and Noted about the large plastic deformation

Indeed, I try all types of Concrete material in the library and of all the simulations failed. Just took the screen shot of the last simulation.
Here are the screen shots for normal concrete material and still the simulation failed. 

And one more question, wonder if the concrete<normal> can withstand large deformation or not? And should I change large displacement into small displacement?

-Best Regard 

[AstroJohnPE]

Hi hot.camp

I may have missed where you specified which material model you are using, but one of the images you provided implies that you are using a "von Mises with isotropic hardening" or "von Mises with kinematic hardening" material model. That material model is for metals -- something with a clear yield stress and plastic deformation. I would not suggest that you use those material models with a concrete-like material.

Also, the material properties for those three concretes that you show in your image are incomplete.  The software reads the properties in the library ("Tools > Options > Manage Material Libraries") and calculates some parameters. The fact that the strain modulus is a negative number as shown in your image indicated to me that the material properties were incomplete. The % Elongation is "missing" from the material library. (In fact, a lot of the materials in the material library have incomplete material properties. Considering that there are (or were) a dozen or more analysis types and dozens and dozens of different materials models (like orthotropic, temperature dependent, viscoelastic, etc), it is impossible to find all of the material properties needed for all of the analysis/material model combinations.)

So at the very least, you can enter more accurate material properties -- assuming that you are confident the von Mises material model will provide the result that you want, or switch to a different material model.

[zhuangs]

"Large displacement" is a safe option for nonlinear analysis types.

For the first figure you attached, the hardening modulus is -31026400000, which is a garbage value.  If you really want to simulate concrete material with plasticity material model, you can try the value of -31026400000 to 1/10 or 1/100 of Young's modulus.

-Shoubing

[Anonymous]

Hi Dear John and Zhuangs

Noted  and thank you

I have checked the library and seems the software library has not been updated since 2004.

 Would you please tell me if there is any updated library available which I can refer to it? I work on civil structures so most of analysis has to be conducted in  Ultimate limite State, I have an issue to mesh the bars also but that's another case.. 

Thanks 🙂

Best regards