Generalized Garofalo Creep Law in ANSYS Engineering Data

- November 21, 2021 at 5:32 pm
  
  Andrew_tan
  Subscriber
  
  Hi,
  I would like to model a solder creep behaviour using generalized garofalo law in ANSYS Engineering Data. I saw that there are a total of 4 creep constants are needed for this law. I managed to obtain those parameters in scientific papers as attached.
  However, the reference unit in ANSYS Generalized Garofalo seems not align with the paper. May I ask had I inputted the creep constants correctly? This is because the solver would produce error after I run my simulation with the current input.
- November 22, 2021 at 5:05 pm
  
  mrife
  Ansys Employee
  
  C2 should be in units of pressure consistent with m, s, K, N. So Pa and not MPa. I imagine though if your model is more naturally on the mm scale and not meter, then you may want to change the Reference Units...is 'Table III' from the reference paper? If so then change the reference units to mm, s, tonne, etc. Would need to redo the curve fitting otherwise (I imagine).
  Mik
- November 22, 2021 at 5:12 pm
  
  Andrew_tan
  Subscriber
  
  Thank you for your response. Yes, table III is from reference paper. As can be seen, the C2 is in the unit of MPa^-1. If I am using m, s, K, N reference unit in ANSYS, I have inputted C2 as 6.2653E-8 as Pa^-1 instead of 0.062653 MPa^-1.
  May I know is that correct?
- November 22, 2021 at 8:35 pm
  
  mrife
  Ansys Employee
  
  generally speaking no. To be absolutely correct I'd rather see you perform the curve fitting with the data in the units that you need. Especially when the creep equation has a term like stress to some power. However I think in this case it should be fine as C2*Sigma will be unitless. Does that paper contain any test data for the material?
  Mike
- December 20, 2022 at 9:39 am
  
  shiva.anthati
  Subscriber
  
  Hello Andraw_tan
  Did you got the solution for the problem?
  I am facing almost the similar problem.
  Please let me know.
  Thanks and regards
  Shiva.
- February 10, 2023 at 9:01 am
  
  NAVEEN KUMAR P
  Subscriber
  
  Hii , Your work was good and we are also working on creep analysis .But we could figure out creep constants using strain-time graphs but then we need some benchmark that our work is fine,So we are seeking for res.paper that our analysis is right .So you obtained some creep constant using some res.papers as mentioned. So could you please share with us .It will helps us to understand it better and help us to move forward.