Analysis Of Strength And Fatigue Performance Of Vascular Stent During Service

As the most effective treatment for cardiovascular disease,the crucial role of vascular stenting has been constantly increasing.In recent years,the material,structure and implantation process of the stent system are mainly studied in the field of vascular disease treatment.However,the analysis of the service state of the affected stent system is still insufficient.With this kind of analysis,the strength and fatigue analysis of stent during service life could be able to have further control for the affected area after treatment.In addition,the finite element analysis has been applied to analyze the stenosis recovery of stent implantation.In this paper,it is also discussed the coupling effect of the stent system with respect to the blood flow field as well as the variable flow field load which is used as a new key factor in performance evaluation under the service life of the stent.The contents are shown as follow:At the implantation stage,the magnesium alloy and the stainless steel vascular stents through numerical simulation of the stent-combination has been compared.It is found that the maximum stress points and critical points of the two material are all in the vicinity of the inner surface of the support.In this way,the change in parameters such as rebound rate and stenosis rate can be obtained;In the combined model of flow-solid coupling analysis,the support is under the deformed state,the recovery effects and potential hazard of blood flow parameters,for instance,the speed,the pressure and the wall shear stress on stent implantation are discussed.The peak stresses of the stent under the action of blood flow is acquired by the load amplitude of the fatigue analysis;By taking the blood load that acting on the deformed stent as the alternating load of the fatigue analysis,the fatigue life and the damage location prediction is obtained by fitting the SN curve.It turns out that the life span of both magnesium alloy and stainless steel is over the life expectancy of the human body reckon without the blood flow corrosion.Finally,the effects of surface roughness,overload sensitivity,residual stress and algorithm correction on lifetime assessment are optimized and compared.