Effects of varying slotted tube (stent) geometry on its expansion behaviour using finite element method

In this paper, results are presented of non-linear finite element simulations performed to investigate the effects of varying the geometry of slotted tubes (stent) using finite element method. The analyses were performed using finite element packages LS-DYNA explicit solver for solution of the problem and ANSYS (Version 5.7) as pre- and post-processor. The analyses involved five different designs of slotted tube stent with different geometry. Besides the standard slotted tube stent (width of slot = width of strut), the changes of geometry include 10% increase of width of the slot, 10% decrease of width of the slot, 10% increase of length of the slot and 50% increase of number of the slot. All the slotted tube stents were subjected to different pressure loads, respectively. In order to reduce the solution time, only one-eighth of the model was developed by taking advantage of symmetry. A bi-linear elasto-plastic and hyperelastic material models were assumed for the slotted tubes and the balloons respectively. The deformation characteristics of the slotted tubes were analysed. The displacement, stress distribution, elastic recoil and foreshortening of the slotted tubes were also computed.