To be precise this is what i am doing
I have 2 cylinders( which
would later be replaced by stent and hollow tube resembling artery) one
made of Nitinol and other made of Hyperelastic Material PDMS( material
properties are inputted)
The Outer diameter of the Inner cylinder is
7.5mm while in the Inner Diameter of the Outer cylinder is 7mm. The
Outer cylinder is Hyperelastic, Inner is Nitinol
These are my steps
Step1: Compression of Nitinol cylinder
Step2:
Self expansion of Nitinol cylinder so that the outer surface of Nitinol
cylinder contacts Inner Surface of Hyperelastic cylinder. This contact
is frictionless.
Step3: The Inner Nitinol Cylinder is then pulled
by applying displacement boundary conditions to all nodes of the
Nitinol Cylinder , while Hyperelastic cylinder is fixed and can move
only in the radial direction. In this step, i am applying a friction of
0.5 between the two cylinders
I am querying NFORC3,Reaction
Force(RF3), which should , as per my understanding, give me the pullout
force required for pulling the Nitinol cylinder by 4mm. Also this force
should be dependent on the coefficient of friction, ie if i increase
coefficient of friction to 0.8, the queried NFORC3,RF3 should increase.
This is not what is happening. even if i reduce coefficient of friction
to 0.05, there is no change in force. Can you help me reason why this
is happening.
Please refer input file run1.inp and run2.inp