Doubts regarding topology optimization
Altair EmployeeHello,
I have been working on Topology optimization on a solid cylindrical structure of thickness 20mm.(trial)
Objective: To minimise mass
Contraint: deflection < 20mm
responses: mass and deflection.
Is it possible to carry out topology optimization ? An error shown on the output file.Screen shot of output file is attached here. Please help me.
Answers
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Hi Meera,
As the error mentioned, please check for any RBM. Make sure you constrained all degrees of freedom.
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Ok. Also after optimization my structure has no continuity.How to force a constant cross section along a given direction in optistruct
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Hi @meera
An image would help to understand your question.
Anyways, you can play with ISO value for better design. If this did not help, you can add manufacturing constraints like minimum and maximum membersize, grouping patterns, etc...
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Hai,
In my output file, error -topology optimization cannot be performed due to possible rigid body mode. Please help me to solve the problem. Here i attached the screenshot of my model.
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Meera,
Kindly provide the .fem file or .hm file which has all optimization and analysis setup instead of raw geometry file.
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Here attached .fem file. Please help me.
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Hai, in my outputfile error: In static load case 1 ,the compliance is negative or large 3.33976e+008.
Optimization/buckling analysis cannot be performed due to possible rigid body mode.
FEASIBLE DESIGN (ALL CONSTRAINTS SATISFIED). What is the reason? Please help me0 -
helloo...
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Hi Meera,
Sorry for a late reply, the model is taking long time to run on my local machine.
I think some how the bottom material from the designable component is removed and this is what make it too compliance to the applied load.
Maybe you can try with adding minimum and maximum member size constraints to your model and try again.
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K . Thank you. I will try.
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Hai, in my outputfile, error: In static load case 1 ,the compliance is negative or large 3.33976e+008.
Optimization/buckling analysis cannot be performed due to possible rigid body mode.
FEASIBLE DESIGN (ALL CONSTRAINTS SATISFIED). What is the reason? Please help me .0 -
Hi meera,
I tried to have a look but it's too much for my laptop.
In such a simple model you should reduce drasticly the element count, it would be easier to troubleshoot and then if needed increase the number of elements.
In a topology optimization you only going to get an ideia where to put material so the element count should be much much lower, and the goal is to use as few elements as possible to achieve faster runs. Even 2D shell would give a good estimation. Then for the final static analysis increase the element count but still not that much.
Best regards,
Gonçalo
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Thank you for your reply.
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