PEEQ and PE differences ??

[Carolina Zambrano]

Hello all

Untill now is not clear for me whats the difference bettween equivalent plastic strain and plastic strain and why when I used a plastic model I should show my results in fuction of PEEQ

Thanks in advanced!!
Carol




[Non-text portions of this message have been removed]

[Dave Lindeman]

In ABAQUS, PEEQ refers to the equivalent plastic strain, and PEMAG
refers to the plastic strain magnitude. Both are scalar measures of the
accumulated plastic strain. For proportional loading, the measures
should be equal. However, for loading with reversals, PEEQ will
continue to increase if the plastic strain rate is non-zero (regardless
of sign). So, in general, PEMAG is the preferred measure. See the
Theory Manual for more information.

PEEQ and PEMAG are generally used since they correspond to the plastic
strain value on the uniaxial stress-strain curve. PE is used only if
you are interested in component values/orientation.

Regards,

Dave

-------------------------
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

Post by Carolina Zambrano
Hello all
Untill now is not clear for me whats the difference bettween equivalent
plastic strain and plastic strain and why when I used a plastic model I
should show my results in fuction of PEEQ
Thanks in advanced!!
Carol
[Non-text portions of this message have been removed]

[Carolina Zambrano]

Thank you. it was very helpful your explanation

Regards!!
Carol




________________________________
From: Dave Lindeman <***@mmm.com>
To: ***@yahoogroups.com
Sent: Tuesday, February 17, 2009 8:50:49 PM
Subject: Re: [Abaqus] PEEQ and PE differences ??


In ABAQUS, PEEQ refers to the equivalent plastic strain, and PEMAG
refers to the plastic strain magnitude. Both are scalar measures of the
accumulated plastic strain. For proportional loading, the measures
should be equal. However, for loading with reversals, PEEQ will
continue to increase if the plastic strain rate is non-zero (regardless
of sign). So, in general, PEMAG is the preferred measure. See the
Theory Manual for more information.

PEEQ and PEMAG are generally used since they correspond to the plastic
strain value on the uniaxial stress-strain curve. PE is used only if
you are interested in component values/orientation.

Regards,

Dave

------------ --------- ----
Dave Lindeman
Lead Research Specialist
3M Company
3M Center 235-3F-08
St. Paul, MN 55144
651-733-6383

Post by Carolina Zambrano
Hello all
Untill now is not clear for me whats the difference bettween equivalent
plastic strain and plastic strain and why when I used a plastic model I
should show my results in fuction of PEEQ
Thanks in advanced!!
Carol
[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

[Uday komaragiri]

Couldn't resist answering...

In simple terms,

PEEQ - Effective Plastic Strain - Scalar
PE - plastic strain - Tensor (all 6 components, being symmetric tensor)

PEEQ is the strain equivalent to MISES Stress.

PEEQ = sqrt((2/3)*PE_ij*PE_ij) - incremental terms

As you can see, PEEQ is simple and convenient.. hence used to extrapolate
from 1D to 3D.

Cheers,
U


On Tue, Feb 17, 2009 at 3:25 PM, Carolina Zambrano

Post by Carolina Zambrano
Hello all
Untill now is not clear for me whats the difference bettween equivalent
plastic strain and plastic strain and why when I used a plastic model I
should show my results in fuction of PEEQ
Thanks in advanced!!
Carol
[Non-text portions of this message have been removed]
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[Non-text portions of this message have been removed]