×
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!
  • Students Click Here

*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

Jobs

Abaqus Linear kinematic hardening input for Hill's anisotropic yield criteria

Abaqus Linear kinematic hardening input for Hill's anisotropic yield criteria

Abaqus Linear kinematic hardening input for Hill's anisotropic yield criteria

(OP)
Hello,

I am trying to implement a simple plate with a hole example for Hill's anisotropic yield criteria in Abaqus.

The material properties are
1. yield strengths y11=6kN/cm2, y22=1kN/cm2, y33=1kN/cm2, y12=0.57735kN/cm2, y23=0.57735kN/cm2, y31=0.57735kN/cm2,
2. Linear kinematic hardening constant H=1kN/cm2

For hardening, abaqus takes input in the form of data points (yield strength Vs Plastic strains). I am not really sure of how to convert these properties into data points that abaqus requires.

I have initially developed a code in matlab using structural tensor theory and verifying those results with abaqus. As of now, I am using the values from my matlab code to run this abaqus simulation.

This is how I calculated the data point values from matlab:
I took an element with the highest plastic strains and followed its trend. I took the stress values when the increment first enters plasticity algorithm. I calculated the equivalent stress (=2/3*(sqrt(Sig ij)) from these values and used it as initial yield point. (Sig0=x, Ep0=0)

I then calculated the equivalent stress and equivalent plastic strain for the final increment for this element. (Sig1=y, Ep1=z).

For linear kinematic hardening, abaqus needs two data points - Initial yield stress and yield stress for some plastic strain. Using the above values I am able to run the abaqus simulations but my abaqus results are slightly higher than my matlab results. The contour plots for plastic strains in both cases looks similar though.

Can someone please help me or direct me to some source where I can find the exact way of calculating these data points from the given material properties?
Note:I have checked the abaqus theory, analysis and other related manuals but am still not able to figure out the solution.

Thanks

RE: Abaqus Linear kinematic hardening input for Hill's anisotropic yield criteria

The formula for the linear kinematic hardening modulus looks simple in the Users Manual. What's the problem in using this to calculate the second data point?

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!


Resources