nikhilramam
Mechanical
- Jun 15, 2014
- 2
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?
Thanks
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?
Thanks