Study of mechanical performance of stent implants using theoretical and numerical approach.

摘要

Coronary heart disease kills more than 350,000 persons/year and it costs ;In this research, the mechanical properties of a stent based on the rhombus structure were analyzed and verified by means of analytical and numerical approaches. Theoretical models based on the beam theory were developed and numerical models were used to analyze the response of these structures under various and complex loading conditions. Moreover, the analysis of the stent inflation involves large deformations and large strains. Nonlinear material properties also need to be considered to accurately capture the deformation process. The maximum stress values were found to occur in localized regions of the stent. These regions were generally found along the inner radii of each of the connected links connecting each of the longitudinal struts. Stress values throughout the whole stent were typically much lower. The peak engineering stress values were found to be less than the material ultimate strength (limit stress 515Mpa), indicating a safe stent design throughout expansion range. Lastly, the rheological behavior of blood can be quantified by non-Newtonian viscosity. Carreau model is introduced and simulates the situation in the artery.