dEFORMATION pLASTICITY IN aBAQUS 1

[fshahangi]

Hi All,

I am trying to analyze spring back of metal in V bending, my problem is with material properties, actually I used deformation plasticity but when the punch goes up the plate does not get deformed and goes back to the first position, also I tried to use the abaqus example and insert yield stress - plastic strain manually, this one worked but for other materials I don't know how I can find the yield stress - plastic strain relation!!!
Can anybody help me on this issue?
tnx

 

[Milad1989]

Hi,
Considering defining plasticity you should have experimental data. Specially for materials that don't have significant plasticity information in literatures. Regarding to this data you can specify yield stress and plastic strain from true stress and strain that the inversion formula exists in ABAQUS analysis user manual.
Hope this help


Milad Mohamadzadeh
Wood Structural Engineer

 

[fshahangi]

Milad jan,

Thanks for your response, but my material is Aluminum 5005,which I have all mechanical properties, but when I put them in deformation Plasticity section, the plate just goes back to it's initial position after I remove the punch!
Thanks for your help.

 

[Milad1989]

shahangi aziz..

Considering your response, I don't think your problem is with defining plasticity, because your work is correct. I suppose problem is somewhere else. Did you define densities appropriate? Or did you follow ABAQUS unit direction? Maybe the punch property is not correct for causing deformation in plate! I could have better response, if I see your model picture.


Milad Mohamadzadeh
Wood Structural Engineer

 

[fshahangi]

Thanks man,

Actually I checked all the data 2000 times! but something is wrong! here is the data that I use for Aluminum 5005 (I used mm for my units then i do not put Mpa)

Young's Modulus 68948
Poisson's ratio 0.33
Yield Stress 41.369
n: hardening exponent: 1/0.293912 = 3.4023
Yield offset: 0.2% = 0.002
Density: 2.7 E-9

Thanks for your help again,
Khosh bashi,
Farzad,

 

[corus]

If the material doesn't reach yield then you'll only get elastic behaviour. Plot PEEQ to see if you have residual plastic strain at the end of the step.

Tara