×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

finding the larsson miller curve based on raw data

finding the larsson miller curve based on raw data

finding the larsson miller curve based on raw data

(OP)
Hi all,
How do i determine a larson-miller regression line based on raw creep data (time, temp, stress)? The material doesnt exist in the standards.
I assume i could do a spline based of the data?

I guess what i am looking for is a larson-miller parameter calculator, but i am certain i am oversimplifying this immensely :)

Appreciate any form of guidance.

RE: finding the larsson miller curve based on raw data

you could use C=20 to simplify P = f(σ) = T (log t + C. if not use P = f(σ) = T (log t + C(σ))·10^−3 to get C. then run stress σ vs parameter C, C(σ) = -A σ + B regression with at least 3 stress data points.

RE: finding the larsson miller curve based on raw data

And then continue the process and fill in with a lot more data points.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: finding the larsson miller curve based on raw data

(OP)
Thank you for the response,

I have the data set in the link below. What is the correct way to determine a lower scatter band representing a 95% confidence level?
Is there a certain method that is used to determine creep values, or is it sufficient to do a spline and then determine a standard deviation? I am not sure how to achieve this, though.

Is this possible to achieve in Excel with no addons?
I also have access to Mathcad.

My goal is to determine an allowable stress for an ASME pressure vessel.

https://homepages.abdn.ac.uk/h.tan/pages/teaching/...

edit: corrected the link

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close