Dear sir,
I am modeling ligament structures in the knee joint finite element model
with non-linear springs and I am successfully getting non-linear
displacement curve.
My only problem is with the calculation of tension in the springs. I
have a set of non-linear springs representing a particular ligament in
the joint, which is having an elongation when I apply the forces on the
joint. I am giving pre-load to the springs so that they do not have any
slack in them before the analysis. I am also specifying the stiffness of
the springs (corresponding to the stiffness of the ligament material). I
cannot use connector elements. In the post-processing,I am trying to
check the S11 of the nonlinear springs and all I could see is a decrease
in the value i.e. a value less than the pre-load I specify.
If the springs are having elongation, then they should have tension in them. Where can I check this tension?: