material with two variables

[gst77]

Hello everyone ,
I am adding a new material to OpenSees and I've seen that all materials depend only on the strain , then with the value of strain can obtain the new state.
I want a material which not only depends on the deformation but also depends on the level of axial load , frictional materials where resistance varies with the axial load and the sign depends on the displacement . Can this be done ?
It would be like the frictional material proposed in the Crisafulli's thesis .

Thank you very much for your help!

[gst77]

Can I call the material using the strainrate as Axial force?

p.e.:in the element definition:

theMaterial->setTrialStrain(strain,Axialforce)

In this way I can use the Axial force in the material model.
Is this possible?

Thank you very much for your time and help.

[fmk]

in theory you could if the element you write was to pass the Axial force .. in practice it is better not to mess with the wrong interface as someone will come along and possibly use your material with a Truss element and i would be better to write your element that creates and uses it's own subclass of uniaxialMaterial.