Thanks

Rick

Is there a simple way to enter creep data into the material
editor? When I choose "Include creep effect", I get a dialogue for
(3) Creep constants (1,2 &3). From the help it seems Simulation
uses the "Classical Power Law for Creep (Bailey-Norton law) which
also has (3) constants (0,1 &2). Are they the same and in the
same order? And finally, how do you derive these constants from
standard isochronous stress-strain families of curves?

Thanks

Rick

Thanks

Rick

- Hello Stephen,

Have you had any success using creep analysis in 2009? I believe we have the proper creep constants for nylon and it always aborts on the first step (regardless of sing elim factor, conv tolerance etc). The cosntants we are using are:

C1 2.802e-11

C2 1.117

C3 0.059

CTC 0 (isothermal case)

Do you have a set of constants for__any__material that is known to work?

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