Thanks
Rick
Bumping this old post.
I have been searching and requesting data from our supplier (custom blender) and have come up empty on finding the proper time, temp, stress data on a 25% glass filled 66 nylon needed to calculate the creep constants. I have been able to come up with a creep modulus chart (BASF Ultramid materies are one of the few that list this information) for various stress levels at different temperatures over a time period. Is it valid to just solve with the much lower creep modulus and not use "include creep affects" and the C0, C1, C2?
For example the room temp tensile modulus is 1,200,000 psi. From this chart the room temp creep modulus at a 4,300 psi stress level at 10,000 hours is about 51,000 psi.
SW Simulation maps the constants as you assumed
C0 = CreepConst1
C1 = CreepConst1
C2 = CreepConst1
CT = CreepTC
To calculate these constants you need two sets of time, temperature and stress results to produce a given strain. An example of this for stainless steel can be found here http://www.fanagalo.co.za/tech/tech_grade_310.htm .
Once you have this data you have to solve the power law eqations as a set of simultaionus equations, so break out your old math books.
I hope this helps.
Regards
Stephen