I am trying to determine the constants described in the help file to model creep life with simulation. Does anyone have any experience doing this? So far, I haven't been able to find a valid solution using a system of four equations. I found the link showing an example problem where C2 is assumed to be 1 (http://www.motovated.co.nz/newsletter/aug13/FAQID__x394.pdf); the only problem with this is they say it is usually safe to assume C2 = 1, but don't say when it is not. Below is an image of the creep life data we're using to determine the constants. We will be using Heat No. WWS.
Any help would be greatly appreciated.
Any value less than 1 for C2 results in a smaller amount of creep strain, so it's a conservative assumptions to set C2 = 1. To calculate the values of C0 and C1 for Heat No. WWS, you'll need to use either the 1600 deg F or 1800 deg F data sample. This will also assume that you're analysis is done at a constant elevated temperature.
For 1600 deg F you have two equations:
Here you have two equations and two unknows, so a unique solution exists.
For 1800 deg F you have two equations:
Here you have two equations and two unknows, so a unique solution exists.
Make sure to use consistant units when calculating your constants.