Abaqus nonlinear Strain-Stress Curve

Hello Friends,

I am using ogden material model and &#305, have my coefficients. I am running analysis with abaqus. In Result of uniaxial tension analysis, strain stress curve is linear. But it must be nonlinear.

How can I solve this problem? Could you please help me?

For example,

Ogden 3 coefficients

M1= 0,000031095

exp1=1,0632600

M2=0,658686

exp2=2,6659000000

M3=0,0038656200

exp3=3,0326200000

thank you in advance

best regards

Not sure why. It looks like you are using a non-linear elastic model.
Are the strains large enough?

-Jorgen