Why not model them as time-varying viscoelasticity and plot the respective curves?

Hi Vikash,

Thank you for your answer.

I have the viscoelastic behaviour of the two materials. I am trying to determine their relative critical energy release rate evolution with respect to time. Is there any way to relate the viscoelastic behaviour of the two materials to their relative time-dependent critical energy release rate evolution?

Thank  you

Thomas

Have you found the time constants of the two materials? Whether you can relate them or not depends on their characteristics and behaviour. I cannot say unless I have all the information.

 Hi Thomas,

the time dependence of the fracture toughness is in first approximation the same of the yield stress. Assuming that the yield stress dependence on time is the same of the modulus (which is not always a correct assumption), you can extimate Gc(t). Check my PhD thesis for more references on viscoelastic fracture theories

Thank you both for your answers! They are very useful. I think that reading your thesis, Tommaso, will be very insightful. And I think you are right Vikash in saying that I can relate the time-dependent behaviour of the material to their time-dependent fracture toughness.