I'm currently working on a design of experiments to define the behaviour of a LSR lip seal under cyclic thermal and mechanical loading. The temperature range goes from -40°C up to 140°C. After around 1400h of cyclic testing the seal is leaking. The new experiment matrix should help determine the parameters to simulate this failure and make it possible to detect the place and time of the failure. I want to crosscheck and discuss my material hypothesis and the design of experiments with someone. I'd be thankful for any input.
Standard tests (tensile uniaxial / biaxial, compression, shear) were already done at ambient temperature and comparison with the behavior of a similar material at elevated temperatures shows that these loads behave quite consistently over the proposed temperature range.
I think that accelerated stress relaxation due to thermal and chemical degradation of the material is the major contributor to failure and I want to test stress relaxation on elevated temperatures and certain time intervals to define the Prony parameters to describe these degradation effects.
With the data from the standard tests and the prony parameters I want to fit a BB-model for the lip seal. I'll probably use MCalibration for it, since it seems to be user-friendly and easy to use.
Am I missing any parameters or experiments for this model? (I have compression with two different strain rates)
Thank you for the help.