| Abstract: | After first implantation of a metallic stent into cardiac vessels in 1986 stent implantation has become a standard technique for treatment of coronary heart disease. During implantation of balloon‐expandable stents, the structure of the stent undergoes high plastic deformation. Despite the fact, that stents are used for more than 15 years nearly no information about the mechanical and micro structural process during dilation are known. The present paper presents a detailed study and comparison of the experimental and the simulated expansion behaviour of metallic stents. Used material models are discussed and crystallographic details are presented. Dilation curves describe the behaviour of balloon‐expandable coronary stents. The dilation behaviour depends on both the materials properties and the design of the stent. A numerical simulation of the dilation process by means of FE is suitable. A comparison of the experimental measurement and the numerical simulation demonstrates, that a Cauchy stress‐strain material model should be used for numerical simulations. A local failure criterion is introduced, which considers void initiation as a criterion for mechanical failure. |
