Adding visco-elastic properties in ANSYS Workbench

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masud407 posted this 02 November 2018

I want to add the viscoelastic properties of muscle in ANSYS workbench. Can anyone give me insight about the procedure of adding viscoelastic properties in ANSYS workbench?

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SandeepMedikonda posted this 02 November 2018

Please take time to go over this section from the manual.

Section 1

Section 2

Discussion 1

Hope this helps

Regards,
Sandeep
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masud407 posted this 13 November 2018

Hey Sandeep,

 

Thanks for sharing. However,your referred article just introduced the concept of viscoelasticity which may not help. I need to add the viscoelasticity of material. So what information should I need to insert? Should I need to fill up the table for  prony shear relaxation and  shear data-viscoelastic? Do I need to insert the initial shear modulus(Mu) and incompressibility parameter(D1) under neo-Hookean tab? 

peteroznewman posted this 13 November 2018

Masud,

Why do you want to use viscoelastic properties for muscle? What is the behavior that you want to add to your model? I know you are working on human body response to vibration coming through a seat.  There is a lot you can do with Damping properties, without having to go to viscoelastic materials.

What range of times do you want the muscle to have appropriate viscoelastic properties?  It is for just a few seconds, right?  I say that because the properties that work well for a few seconds will give ridiculous results on the time scale of hours.

Regards,
Peter

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masud407 posted this 13 November 2018

Hey Peter,

 

I am trying to use viscoelastic properties as I am not finding a constant value of young modulus for muscle . Also, a lot of works have been done to analyze the viscoelastic properties of muscle and mentioned muscle as viscoelastic material. Yes, i have to applying vibration maximum of 2 minutes time frame. I understand that you mentioned in the last line. But i am just trying to consider the muscle according to literature. So can you please tell me what information that I need to use to show the time variant elastic modulus for the viscoelastic muscle? Thanks. 

masud407 posted this 5 weeks ago

If I simulate it for maximum of 120 sec with a constant elastic modulus for maximum of 50 Hz, will it be significantly different than the result of using viscoelastic properties?

jonsys posted this 4 weeks ago

You should insert the Shear Data (Shear Modulus-Time relation) and get the Prony Shear Relaxation coefficients by doing a curve fit.

This post will definitely help you how to do it because it has a lot of screenshots (there might be some additional information there about temperature and shift functions but don't focus on them because you don't need them).

Try it and come back with specific questions about which part are you struggling with

masud407 posted this 3 weeks ago

Hello Jonsys,

Thanks for your comment. After going through your post, I have some inquiry:

 

1) How should I insert shear modulus-time relation data? Isn't it the same as obtaining data from the equation of G(t)? or It's the value obtained from stress-relaxation data?

2) Should I include the properties of isotropic elastic properties?

3) for curve fitting, I changed the seed values. However, the curve (obtained from sdec-red marked) is not changing, in fact it's showing a straight line. What should I do to fit the curve?

 

Thanks for your time and effort. Looking forward to having your valuable reply.

masud407 posted this 2 weeks ago

As I have seen that I have to add isotropic elastic properties to define the viscoelastic properties, Can you please tell me what should be the value of elastic modulus that I need to insert? Is it the same as the value of E(t) at time t=0?

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