Modeling point to point force actuators

RIZA BAYOGLU_21565

Hi,

I like to model spinal ligaments as 1D, point to point force actuators obeying the following formula where the force in the actuator is a function of strain and some material constants: F_lig (strain) = a*ln(e^(strain + b)/d + 1) + c

Could someone comment on how this can be modeled in HyperMesh to run a non-linear static job in OptiStruct?

Thank you,

Riza.

Adriano Koga_20259

hi @RIZA BAYOGLU 

 

If i understood right your question, you want to create a 1d element with NL stiffness, right?

 

You can create CBUSH element and assign to it a NL curve (force x Displacement) enabling the KN line in the PBUSH property, and thus adding a TABLED1 table with your force x displacement curve.

But you will need to give it the explicit curve, not an equation, ok?

Does this fit you?