Learning Forum

[Ali aviation.khademi]

Hello Dears,

I have defined Prony series (relative modula and relaxation time). I did curve fitting by Matlab before. Now, I have a simple model (dogbone) . I have a 4 steps analysis. 1-I've applied dispacement of 3 mm displacement. 2- I've kept it for a certain long time. 3- i removed the load 4- a step of long time without any load to capture the recovry phase. The problem is that i cant see any creep control option under "Analysis Settings". I had it before when using Norton law for creep. Could you please help me with that?

I use 2024 R1

[Lydia]

Hello Ali,

In viscoelasticity, all those viscous deformations are reversible. In viscplasticity, they are not. Prony series is viscoelasticity and creep is viscoplasticity. So creep control is only available if creep material models are defined, that's why you do not get the option in this case. 

Check also this doc link 1 

 

[Ali aviation.khademi]

Esteemd Lydia,

Thank you for your reply, I have a question. If i can not use prony as a creep model, so how can i use a creep model such as Norton for modeling the creep and use prony at the same analysis to capture the recovery and relaxation phase. is there any way? I have tried it before and encuntered an error that told me i need to define just one of them per analysis. 

Actually I need to define an engineering data to capture creep,relaxation and recovery for my model. To make it clear, i have a model and want to apply a dispalcement in a very short time, the in next step keep the deformation for a certain time to obtain creep and relaxation. Next, i will remove the load and in the last step i will give a time to my model for the recovery phase. 

I know that Prony series can be used for both creep and relaxation. but in ansys i have to use another model. how to use creep models and prony at the same time?

 

Thank You !

[Lydia]

There is a list of all supported material model combinations here. 

You can also see the creep equation different creep models use here