Simple question about optimization

[dkakth]

Hello dear colleagues

Can you explain me simply the meaning of ISO surface (mat prop normalised) into topology optimization results...

In a strain energy minimalization optimization i have setup a 0.5 of the volume to be used, but tweaking the isosurface varies it between 0 to 100 %

How can i just extract the result with the proper amount of volume removed (according to optimization computation). It is != of the ISOSURFACE=0,5...

:/

sorry for the noob question

kind regards

 

[FEA way]

Create a contour plot of the MAT_PROP_NORMALIZED variable on undeformed shape with view cut turned off (or value of isosurface variable set to 0). You will see which elements are fully dense (MAT_PROP_NORMALIZED = 1), which are scaled down to low stiffness by the optimization algorithm (MAT_PROP_NORMALIZED = 0.001) and which are in between. Then manipulate the isosurface variable in View Cut Manager to set which elements are removed. You should always make sure that fully dense elements are not removed. Usually default isosurface variable value of 0.3 is fine. But if you want to remove or keep more intermediete density elements then you can adjust the value.

A nice trick is to switch Visible Edges to Free edges (Common Plot Options) and turn on Below Cut in View Cut Options for Op_Surface (leaving On Cut and Above Cut turned on as well). This way you will get isosurface overlaid on contour plot.

 

[dkakth]

Thank you FEA way, but what happens if in optimization task i have thicked "delete soft elements in region" ?

 

[FEA way]

With this option turned on Abaqus deletes soft (void) elements from mesh so that they are not taken into account in calculations. It’s recommended to use this option in nonlinear problems when soft elements may become severely distorted and cause convergence issues. Otherwise you can leave it turned off.