simtk.org

Hi everyone,

I need to set different properties to the same wall of my model. Is there a way to do it using SimVascular?

Thank you for your reply,
Valentina

Hi Valentina,

Do you want to set the properties for svSolver or svFSI solver? What kind of properties do you want to set, wall thickness, E, density, etc.

How would you like to identify the regions with different properties? For example, you could set a property based on the radius of a vessel or identify regions (polygons) within a model.

There is no functionality within the SV GUI to identify regions with different properties. However, you could write a program to create a wall with multiple faces and then assign each face a different material property using the SV GUI. Face IDs are defined using the ModelFaceID CellData array in the VTK .vtp files used to store an SV model.

Cheers,
Dave

Hi Dave,

Thank you for your reply.

I'd like to set the properties for svSolver and in particular I'd like to set different wall properties (density, wall thickness, E, Poisson ration) to two different regions of the same wall, so I will follow your advice and I will write a program to create a wall with multiple faces, thank you very much!

Best regards,
Valentina

Dear Dave and Valentina,

I'm facing the similar problem; I also need to set different material properties to different regions of the solid wall. For the first step, I'm using a simple straight pipe of 0.15mm wall thickness (similar geometry to the demo case "cylinder_ALE_FSI"). I'm using the svFSI solver. Now, I want to set a different elasticity modulus (later probably a different constitutive model as well) to only part of the entire pipe (say, only its middle region with a length equal to the pipe diameter).

In the demo case "cylinder_ALE_FSI", material properties are assigned to the entire solid wall (say, domain-2 while fluid domain is defined as domain-1) as follows
Domain: 2 {
Equation: struct
Constitutive model: nHK
Density: 1
Elasticity modulus: 7e+06
Poisson ratio: 0.4
}
Does it means that I have to define the middle region of the pipe as a third domain and then to assign a different material property to the third domain? Or, should I create and use more face IDs to do so? Could you please give me some hints/tips for creating more domains and/or face IDs?

Thanks,
Haifeng

Hi Haifeng,

It appears that you can define different material properties on different domains. See viewtopicPhpbb.php?f=188&t=11951&p=34280&start=0&view=

SV does not have the capability to create mesh .vtp or .vtu files that can be used for this, you will need to write a program in Python or C++ using VTK to identify the different domains and write out the .vtp or .vtu files.

Cheers,
Dave

Hi Dave,

Thank you for your clarification and the referral link!

Cheers,
Haifeng