Large displacement / plastic strain analysis

- June 24, 2020 at 4:54 pm
  
  morrowinter
  Subscriber
  
  Hey,
  
  Hello, I want to model a part mainly in bending, in large displacement and with plasticity.
  
  I implemented the isotropic hardening curve in true stresses.
  
  Being in large displacements and with plasticity, I believe i should postprocess the cauchy stresses or, I am wrong.
  How can i do that. I only see Von Mises stresses.
  
  Thanks a lot.
- June 24, 2020 at 6:28 pm
  Wenlong
  Ansys Employee
  Hi,
  
  According to the manual (https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v201/en/ans_elem/Hlp_E_AutoSelectElems.html?q=true%20stress):
  
  All nonlinear stress/strain data should be input as true-stress/true-(logarithmic-) strain. Accordingly, all output data is also indicated as true-stress/true-strain. For small strains, the true-stress/true-strain data and engineering-stress/engineering-strain data are essentially identical.
  
  So if you look at Normal stress and Shear stress output, what you get is Cauchy stress (true stress).
  
  Regards,
  
  Wenlong
  
  ================ Note ====================
  
  If you have trouble opening the links I attached, please see the first useful link below
  
  Useful Links
- June 25, 2020 at 9:18 am
  
  morrowinter
  Subscriber
  
  Thank you for your answer.
  
  Is there something like an equivalent cauchy stress or is it still acceptable to postprocess the equivalent VM stress ?
- June 25, 2020 at 1:53 pm
  
  Wenlong
  Ansys Employee
  
  Hi,
  
  Equivalent stress is V-M stress. It is calculated based on true stress (Cauchy stress) and should be used to compare with the yield stress.
  
  For more info, please see: https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v201/en/wb_sim/ds_Equiv_Stress.html?q=equivalent%20stress
  
  Regards,
  
  Wenlong
- June 25, 2020 at 4:56 pm
  
  morrowinter
  Subscriber
  
  Thank you. Everything is clear.
  
  Best Regards