Polymer material definition using tensile test data (linear part Hyperelastic material model)

Hello 

I am trying to define a Polymer material based on tensile test data. my main issue is the polymer enters the plastic zone after 70% strain.

I am using this polymer in an application that works only in the elastic zone of the material (entering the plastic zone for my application means failure).

I used Yeoh 3rd order (hyperelastic model) to define only the elastic part of the curve ( less than 70% strain) and my simulation ( using static analysis in ansys work bench) works well, is this right? if not I would appreciate it if you suggest the right method for defining the material.

I checked the forum and I understood that Hyperelastic materials should not be used with plastic materials. 

I uploaded the tensile test figure for the polymer.


Best Answers

  • A_zaghloulA_zaghloul Member
    Accepted Answer

    Hi bsista,

    Thank you for your answer.

    I would appreciate it if you suggest specific reference that I can use it to reference this part if available.

    The only thing that makes me confused I calculated the modulus of elasticity form the curve for 10 % strain, the value will be around 25 MPa ( calculated from the slope of the stress-strain curve), and I will assume the poison Poisson ratio=0.49 My question is when I used these values instead of the hyperelastic model the solution did not converge.

    and I got this error

    "internal solution magnitude limit was exceeded ansys workbench"

    shall I stick to the hyperelastic model?

  • A_zaghloulA_zaghloul Member
    Accepted Answer

    Hi bsista,

    I think I fixed the problem by increasing the number of sub steps in my simulation.

    I would appreciate it if you suggest specific reference that I can use it to reference (the hyper elastic part) if available.

Answers

  • A_zaghloulA_zaghloul Member
    Accepted Answer

    Hi bsista,

    Thank you for your answer.

    I would appreciate it if you suggest specific reference that I can use it to reference this part if available.

    The only thing that makes me confused I calculated the modulus of elasticity form the curve for 10 % strain, the value will be around 25 MPa ( calculated from the slope of the stress-strain curve), and I will assume the poison Poisson ratio=0.49 My question is when I used these values instead of the hyperelastic model the solution did not converge.

    and I got this error

    "internal solution magnitude limit was exceeded ansys workbench"

    shall I stick to the hyperelastic model?

  • A_zaghloulA_zaghloul Member
    Accepted Answer

    Hi bsista,

    I think I fixed the problem by increasing the number of sub steps in my simulation.

    I would appreciate it if you suggest specific reference that I can use it to reference (the hyper elastic part) if available.

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