Abaqus FEA - Viscoelastic material showing stress relaxation effect

The strain and stress variation of rectangular shell under rising/sustaining/falling/sustaining strain load.
* CPE8(An 8-node biquadratic plane strain quadrilateral)
The FEA model with viscoelastic material clearly shows the stress relaxation effects during constant strain condition.
Basic guide for how to use viscoelastic material property in Abaqus (Time domain based Prony Series, Dynamic implicit problem)
* Analytical solution of stress variation (from Ref.) is compared with FEA results.
[Ref.] NASA technical report paper - Tzikang Chen, Determining a Prony series for a viscoelastic material from time varying strain data, NASA/TM-2000-210123

[@mariogalindoq]

You don't need to do a dynamic analysis, a static analysis is enough because the inertial forces can be neglected.

[@sunils1056]

Thank you for the nice video.
What is the difference between instantaneous modulus and long term modulus. I read in the manual that it's only a matter of choice and doesn't affect the solution.

[@Ahn.Eng.]

If you think viscoelastic as stress = E(t)*strain, then modulus will change from E(0) to E(t=infinity) (we can think stress relaxation)...then E(0) is instantaneous modulus, E(t=infinity) is called long term modulus.

[@Concreteblockmachineug]

Hello, How can we add temperature effects of Viscoelastic materials in abaqus?

[@haymanmyintmaung6487]

I want to learn more about this, how can I contact you?

[@hayriburakyalin]

thank you very much. Could you load a laminated glass modellin video? is it modelling lineer or nonlineer?

[@Ahn.Eng.]

I used nonlinear geometry option on and CPE8 element type (An 8-node biquadratic plane strain quadrilateral)~