Define TRACTION Stress Strain curve with a function

JulesDANZEL

Hello,

I'm running 2D axi non linear mechanical simulations, and I want to reduce computational time.
I'm using a material law defined by a stress strain curve:

LoiMat = LIRE_FONCTION(NOM_PARA='EPSI',
PROL_DROITE='LINEAIRE',
SEPARATEUR=',',
UNITE=2)
mater = DEFI_MATERIAU(ELAS=F(E=210000,
ALPHA=0.0,
NU=0.3),
TRACTION=F(SIGM=LoiMat))

The thing is: my curve contains 1000 points. To gain time, I tried with a reduced curve (around 50 points), and it works!

Now here is my question: This curve is theoretical, I'm generating it with ASME formulae, so I was wondering if it was possible to use a function as input (so not discretised). Here is what i wrote:

mater = DEFI_MATERIAU(ELAS=F(E=210000,
ALPHA=0.0,
NU=0.3),
TRACTION=F(SIGM=matfct))

with:

matfct= FORMULE(NOM_PARA="STRESS",
VALE="....*STRESS", ...)

I could test my function for a given value and it works, but when Aster runs DEFI_MATERIAU, it crashes:

"error at the time of the definition of the traction diagram: FUNCTION or THREE-DIMENSIONS FUNCTION! "

I couldn't find anything in the doc. I don't know how to define a FONCTION from FORMULA...

Thanks for your time!

Jules