Contact US

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

Johnson Cook strength parameters for AISI 4130 Steel

Johnson Cook strength parameters for AISI 4130 Steel

Johnson Cook strength parameters for AISI 4130 Steel

Hi All,

I want to analyse the the deformation of a tubular space frame chassis by the means of a crash test simulation. I am using Abaqus and will use an explicit solver to analyse the short during event that will undergo highly nonlinear and transient forces. I am currently in the process of setting the material properties and want to define a "johnson cook parameter".

Now I am a new user to Abaqus so i am unsure what the best approach to take here would be. Within the material property under "plasticity". In the example that I have been following, the user has used an generic low graded aluminum material and at the section he has enetered the following parameters in the attatched picture.

If anyone has any experience wth using an explicit dyanmics solver within Abaqus then any information covering this would be greatly appriciated.

Is this just a simple case of plotting the Stress/Strain Curve for 4130 and from that I can derive the Plastic Strain?



RE: Johnson Cook strength parameters for AISI 4130 Steel

The only problem is that strain rates in a crash are about 1,000,000 times those in a tensile test.
Hence, various strain rate dependent models.
The energy absorption, degree of deformation, and crack propagation mechanics all change at real high strain rates.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Johnson Cook strength parameters for AISI 4130 Steel

You will need multiple stress-strain curves to start with simulation, a regular curve with low strain rate, and curves with higher rates up to the order of 10^3 per second to mimic crash. Each curve will give you one yield stress and corresponding plastic strain.
Johnson cook model includes three components: strain harden, strain rate harden, and softening due to adiabatic temp increase. strain harden component will be derived from the regular curve, strain rate harden will be derived from yield stress vs strain curve, softening component will be from adiabatic curves (density is needed).

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


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

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