Creep and failure criteria

[Muzialis]

Hi All,

I have done a creep analysis on a component. Displacements over time have been verified through testing and everything is fine. The Client though wanted a chart LOAD vs. Time to Failure, and I thought it would have been straightforward to use a criteria as max strain.

It turns out though that the EAB of this HNBR compound is somehow dependant on strain rate, i.e. it elongates more (35%) at very low strain rates. This is for constant strain rates and it is not directly applicable to a creep scenario.
I have never relaized this. Is there anybody having had an exposure to this matter?

Many thanks

Muzialis

[Jorgen]

What does EAB stand for?

I have noticed that the failure strain in monotonic loading of elastomers is both strain-rate and temperature dependent. For most elastomers that I have tested, I believe that the failure strain increased with increasing strain rate.

If you have the budget I recommend more failure testing on your compound.

- Jorgen

[Muzialis]

Jorgen,


EAB stands for Elongation at Break (although it is always given as a strain).

Thanks for your advice about the experimental route.

Kindest Regards

Muzialis