Tresca yield criterion

[butho]

Hello everyone,
I was wondering if anyone managed to plot the tresca yield criterion on v.8.4.1., or if someone has any clue about how to implement it ? I tried to understand how the von mises yield criterion works with PSTRE 6 without success.

Thank you in advance,
Thomas

[Yaakov]

Hi Thomas,

I would ask, can you use the tresca yield criterion  in FEAP? or in your own subroutine?

Best regards,
Yaakov

[butho]

Actually I found where the max Tresca stress was (x y) using PSTRess 6,,0 and I used

Code: [Select]

BATCh
    TPLOt                                   !Time evolution for quantities
END
STREss ,,1 x y                       
STREss ,,2 x y                     
STREss ,,3 x y                         
STREss ,,4 x y
Matlab finishes the work

Code: [Select]

clc
clear all
close all

A= [s11 s12 0;s12 s22 0;0 0 s33];
[V,U]=eig(A);
D=V\A*V;

tresca_tab = [abs(D(1,1)-D(2,2));abs(D(1,1)-D(3,3));abs(D(3,3)-D(2,2))];
tresca = max(tresca_tab)
A bit longer than using a subroutine i guess, but i coudnt work that out

[Prof. R.L. Taylor]

Seems you can add MAX SHEAR in the routine that computes the principal values in pltstr.f in the ./plot directory.  For 3-d you can use the slot sp(ii,4) and compute the max from the values in sp(ii,1:3).

[FEAP_Admin]

If you add this, namely,

Code: [Select]

sp(ii,4) = 0.5d0*( max(sig(7),sig(8),sig(9)) - min(sig(7),sig(8),sig(9)) )
Then at the plot prompt

Code: [Select]

PSTRess,4will give you a plot of the max shear.

[butho]

Thank you very much ! That's what I was looking for.

Thomas

[Prof. R.L. Taylor]

YOu probably only need the sig(7) - sig(9) as 7 should be maximum principal stress and 9 smallest one.