Numerical modelling of mechanical phenomena in coronary stents

Abstract

Abstract. Using the finite element method and mathematical models, this study determined mechanical characteristics of slotted-tube stents. A calculation model was developed and a type of material used for coronary slotted-tube stents was chosen in order to evaluate the biomechanical response to changes in geometrical parameters of stents. The numerical calculations were carried out using ADINA software. Stents were made of the four materials, i.e. austenitic steel 316L (Cr-Ni-Mo), cobalt-matrix alloy (Co-Cr-W-Ni) and two titanium-matrix alloys . The effect of the stent geometry was analysed, with emphasis on examination of the effect of key mechanical phenomena such as expansion pressure and a suitable level of stress and plastic strain in stents. Analysis of the degree of foreshortening and dogboning after stent expansion was also carried out.

Numerical Analysis of Mechanical Phenomena in Coronary Stent Made of Titanium Alloy Ti-13Nb-13Zr

“…[º] An elastic-plastic model of material with isotropic strengthening was adopted in the analysis of stents [18]. Mechanical properties of the material studied were adopted within the ranges defined by the standard ASTM F1713 (β) for titanium-matrix alloy Ti-13Nb-13Zr.…”

“…Table 2 contains material data adopted for the study. Dogboning, which is an increment in implant diameter in the proximal and distal ends of the stent, is given by the following equation [13,18,19]: -central diameter of the stent when pressure is applied.…”