# Prof. Yu's Research Group in the Cloud

## Forum

### Macro Analysis using homogenized properties

1. Dear Sir,

I have seen illustrated examples of macro analysis with homogenized properties it is either 2d plate or 3d uniform structure, If someone has macro-structure in 3d and it is flat but 3d with complex geometry including curves and circles than at the time of applying homogenized properties, element orientation should be attentive or not. For curve and cylinder, different element orientation(for different shape)  has to be chosen or it will be included in normal global element orientation (with respect to meshing in Ansys or Abaqus).

Thanking you

Replying to Vivek Dhimole

1. If you include the curved geometries in your SG, then you need to use local coordinates. If your macro structure is flat, you don’t have to include the orientation in the macro analysis as long as the global coordinates of your SG is the same as the problem coordinates for the macro structure. ---- Emailed forum response from wenbinyu@purdue.edu
Replying to Wenbin Yu

1. Dear sir,

If meso scale SG has ractangular Domain and curved yarn from Tex Gen ..than is it ok to do homogenization with global coardinate and then macro geometry is combination of flat line curved and circle inside in it but it is in one part only so it can also be done with assignign element orientation according to its mesh or for same SG local co-ordinate system will be needed for homogenisation and if i use local coardinate system for homogenisation then for macro geometry also  local co-ordinate system needed .

I am confusing as you said in the second line as long as the global coardinate of my SG is same as the problem coordinates for the macro structure.

Means I can always use element orientation according to global coardinate  system  (along its mesh) for any kind of curved+straight macro geometry(in single part) if I am using SG homogenization on the basis of global coardinate system .

2. It is difficult to understand you are trying to do. Please use pictures describe in detail what you are planning to do. ---- Emailed forum response from wenbinyu@purdue.edu
Replying to Wenbin Yu

1. Dear sir,

Please find the attachment of meso and macro geometry is in that case macro analysis can be done with element orientation according to its mesh globally. and I have also doubt that 3D SG and 3D macro geometry should have same XYZ orientation (direction). in that case 3D SG has 1.5*1.5*2.7 mm and macro geom. has 100*40*15 mm dimensions.

3. Still not clear what you plan to do. Please describe what is the problem, what is your planned approach of analysis and where you have questions. ---- Emailed forum response from wenbinyu@purdue.edu
Replying to Wenbin Yu

1. Dear sir,

Mesoscale SG as you have seen in fig with curved yarn and rectangular domain like braided structure ha global coordinate is on the one of the corner's of SG and macrostructure has global coordinate at center of geometry, now if I use element orientation in macro model as per the region selection or global coordinate of geometry (mesh-based) is it ok.

Or in macro analysis element orientation for curve region, and for the circular region will be different.

mainly I have a doubt to define element orientation for macro analysis is it define for complete region or different for different shapes but all shapes are in one part only.

4. Read some textbooks regarding micromechanics and multiscale modeling, then you should be able to have a better understanding. ---- Emailed forum response from wenbinyu@purdue.edu
Replying to Wenbin Yu

1. Dear sir,

Ok I will read,till that please tell that for macro analysis of this part different element orientation is defined for different shapes.or for whole part it will be same with respect to mesh .

5. If your SG has the same coordinate system as your macro structure, and the macro structure can be considered as made of the same SG without re-orientating, then, you don’t have to worry about the orientation in your macro analysis, the orientation is taken care by MSG. ---- Emailed forum response from wenbinyu@purdue.edu
Replying to Wenbin Yu

1. Dear sir,

Ok thank you.

Sincerely