About the meaning of volume fraction
In the setup，there is a parametervolume fraction. When I choose the 30% as the upper limit.
What does it means？It means 30% volume fraction of design space joins in the process of optimization. Am I correct？
What's more，what role dose the other 70% volume fraction of design space play? What changes does these material go through?
Answers

Thanks for answering
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Hi,
Volumefrac response is the material fraction of the designable material volume (material available for optimization). The volume fraction response can be a fraction of:
the total volume, which includes design and nondesign volume
by entity, specifying either props (properties) or mats (materials)
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Altair Forum User said:
Hi,
Volumefrac response is the material fraction of the designable material volume (material available for optimization). The volume fraction response can be a fraction of:
the total volume, which includes design and nondesign volume
by entity, specifying either props (properties) or mats (materials)
Thanks for answering!
I know the 30% is the material available for optimization. But I wanna know how the remained 70% of the volume change?
what state doest the 70% stay? Lowdensity or some other?
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The volume fraction is the ratio of the volume occupied by solid material to the total available volume in the design domain. The remained 70% volume is assigned lowdensity value. When the optimization converges, elements that have very low density are considered to be void, and the remaining elements define the optimal topology.The penalty driven method (SIMP) is described as a ‘soft kill’ method, and allows a gradation of stiffness range between the full value and a very low value.
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