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lamjuv's blog

umat isotropic hardening law

Submitted by lamjuv on

hello everybody

i want to ask when i use isotropic hardening law in umat abaqus. i used uhard subroutine.

my question can be so simple.

how we will enter plasticity values in abaqus. i think in user material after other constant we enter them like this

for exemple:

props(1) young

props(2) poisson ratio

props(3) strain value for the curve maybe 0

props(4) corresponding yield stress value

props(5) other strain value

......

.....

is this right???

thank`s in advance

code error144 and umat isotropy hardening law

Submitted by lamjuv on

hello everybody
i want to develop a constitutive law for fiber reinforced composite. so i am using umat subroutine to simulate it in abaqus.
when i begin analysis i got error code 144.
my question is: is jacobian matrix DDSDDE can be to cause for this error??

and i read that i can use uhard subroutine for isotropic and combined hardening.
using this subroutine we can get yield surface from hardening curve, so we must enter some value in abaqus^material^(yield stress with corresponding strain)

how to configure abaqus 6.10 in windows7 to run user subroutines

Submitted by lamjuv on
hello everybody.  
i have a problem when i want to work in abaqus subroutine (the problem is in installation)
my pc is 64 bit and my system is windows 7
i installed abaqus 6.10.1 and visual studio 2010 and intel visual fortran 11.1.60
but i dont know how to configure abaqus to intel fortran
my problem is how to configure this abaqus to run user subroutines.
 
thank u very much

back stress

Submitted by lamjuv on

hello everybody

i want to know what is the meaning of back stress and its effect on drucker prager yield criterion for viscoelasticity materials

thank you 

problem with creep analysis using abaqus

Submitted by lamjuv on

hello everybody

when i am trying to make a creep analysis using abaqus and it is the first time i do that

when i submit the job, there is an error and a message appear this message is:

 

 

ERROR: DEGREE OF FREEDOM 11 AND AT LEAST ONE OF DEGREES OF FREEDOM 1 THRU 6 

           MUST BE ACTIVE IN THE MODEL FOR *COUPLED TEMP-DISP. CHECK THE 

           PROCEDURE AND ELEMENT TYPES USED IN THIS MODEL.