I am doing some research on nanocomposite modeling (polyurea+carbon nanotubes) in Abaqus. I evaluated the hyperelastic factors from experimental data (uniaxial load).
Now I would like to model the mullins effect, I tried to use the Abaqus tool but the curve doesn't match (the second cycle loading has the same shape as the first cycle unloading).
Here is my model :
strain energy potential = Ogden order 3 (mu1=-10.57, mu2=1.71, mu3=21.42,alpha1=3.78, alpha2=4.39, alpha3=-6.87, Di=0)
Mullins effect (r=2, m=1, beta=1)
1 element (3D hybrid C3D8RH)
4 steps :
1 - load1 (displacement control = 150%)
2 - uload1 (stress = 0.0001)
3 - load2 (displacement control= 150%)
4 - uload2 (stress = 0.0001)
Curve : Nominal strain/stress S22
Could explain me why my stress/strain curve does not match the theory?