Hello everyone, I simulated the inflation of a stent by imposed displacement on each of the nodes. Thus I created a cylindrical frame (R,theta,Z), since my stent is folded around the Z axis. I then imposed a radial displacement U_R on each of the nodes. I left the other DOFs free, except for one node where I also blocked U_theta (orthoradial displacement) and U_Z to avoid rigid solid movements. I used an elastoplastic material with a yield strength of 480, and a very low isotropic hardening (i.e. almost perfect plasticity) "plastic_table": [ [480, 0.0], [580, 100000], [680, 2000000], [780, 3000000] ],
I observe that my simulation diverges, in particular that in view in the plane (X,Y) = (R,theta), all the points do not move by a uniform U_R, some move more than others. Thus we no longer have the expected circle aspect for the stent. We note that this U_R varies from one crown to another, while we have imposed it identical everywhere.
I also note that if I also block U_theta (orthoradial displacement) I no longer have this problem, the simulation converges and all my nodes move well from the imposed U_R. I have not however blocked the degrees of freedom of the rotations (UR1,UR2,UR3).
Do you have an explanation on what looks like a kinematic/behavior incompatibility
Thank you very much,
Cheers
