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Simple Viscoelastic question!

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Hello,

I have a really simple question to ask.
I'm trying to implement my Generalized Maxwell model into COMSOL and I'm not certain how to apply all the parameters correctly. Because when i compare my results to Ansys there is a difference of a factor of 10 in displacement.

this is my function G(t):

G(t)=Ginf+G1*exp(-t/p1)+G2*exp(-t/p2)+G3*exp(-t/p3)+G4*exp(-t/p4)+...
+G5*exp(-t/p5)+G6*exp(-t/p6)+G7*exp(-t/p7) +G8*exp(-t/p8)

I know how to apply the prony terms in the table given.

However in the section long term elastic properties is it correct to insert Ginf as the shear modulus option and instantaneous bulkmodlus K0 dervied from linear modulus relation:

K0=G0*2*(1+ny)/(3* (1-2*ny))

where
G0=G(0)
ny=poisson's ratio
p1-8= relaxation time Tau

??

Or should i insert both G0 and K0 in the longterm properties?
I've attached a picture displaying the parameter options for linear viscoelasticity material model.

Thank you!

Best Regards

Christopher Muturi



1 Reply Last Post 2 avr. 2016, 14:56 UTC−4
COMSOL Moderator

Hello Christopher Muturi

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Posted: 9 years ago 2 avr. 2016, 14:56 UTC−4
Can you tell me how to apply prony series in generalized maxwel model.
Can you tell me how to apply prony series in generalized maxwel model.

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