×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• 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.

# AISI 4130 - Tangent modulus

## AISI 4130 - Tangent modulus

(OP)
What is a reasonable value of tangent modulus for AISI 4130 material? ( 1Cr 0.5Mo Temperature 350 F )

SUMATECH, INC.
www.sumacon.com

### RE: AISI 4130 - Tangent modulus

The Tangent Modulus is the slope of the stress-strain curve at a specific point. Therefore it is not a single value, but varies with the stress. At low stresses, the tangent modulus is the same as the normal Young's Modulus. As the stress approaches the yield stress, the modulus decreases, and this local modulus is called the Tangent Modulus. Since you need to know the stress to know the tangent modulus, it becomes an iterative problem. In a nonlinear material analysis, you can define the full stress-strain curve or use a bilinear approximation with a "hardening slope" which reduces the modulus to a constant single value after exceeding the yield stress.

### RE: AISI 4130 - Tangent modulus

(OP)
Thanks sdm919 .

I should have clarified. The Tangent modulus was
for bilinear-idealization. So the second slope,
after reaching the yield point is what I was
referring to.

SUMATECH, INC.
www.sumacon.com

### RE: AISI 4130 - Tangent modulus

Instead of asking us, plot a stress/strain curve from Et data and fit whatever curve you want.

#### 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.

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:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!