| The heart provides a steady stream of power for human blood. Once the heart valve disease occurs, which will endanger people’s life safety. Valve replacement is a major means of treatment of rheumatic heart valve disease. At present, main methods are applied to clinical valve including mechanical valve and bioprosthetic heart valve. Bioprosthetic heart valve has excellent hemodynamic performance, which don’t need a life-time of anticoagulant, low rate of plugging thrombosis and less complicated symptoms related to the heart valves leading to rising trend in the treatment of heart valve disease year by year. However, because of the valve leaf morphological valve materials and blood flow state and other factors, which make the valve more easy to produce the failure mode, such as tissue calcified, valve leaflets tear and so on. Thus, those factors will not be able to meet the high life expectations of bioprosthetic heart valve in clinical. Mechanical stress is the main reason for bioprosthetic heart valve calcification and valve leaflets tear. So, designed and developed the excellent performance durability of bioprosthetic heart valve is the problem to be solved home and abroad.Paper, firstly, depending on the thin shell theory and fluid mechanics theory, uses the computer aided design software like PRO/E designing ellipsoid surface BHV model. According to clinical data to construct the arterial wall model, then using ANSYS/WORKBENCH to get fluid-structure coupling model of BHV and blood. Based on blood vessels mechanics and cardiac mechanics, using the ALE method to derive the basic framework, principle and coupling equation of interaction between BHV and blood, and to provide the feasibility and importance of interaction analysis on bioprosthetic heart valve, In order to make the force of the model be closer to the real environment, clinical physiological parameters are adopted. Finally, the application of finite element analysis software ANSYS/WORKBENCH on the model of finite element analysis aim to obtain the stress distribution results, and compare several kinds of different parameters on the mechanical behavior of BHV respectively. Through the analysis of BHV mechanical properties, it can be seen that BHV is in working conditions, the maximum equivalent stress and stress concentration appears in the suture zone of BHV and BHV stent. The phenomenon satisfies the clinical data that valve leaflets easily occurs to tear and tissue calcification lesion areas. Through different Poisson’s ratio analysis of bioprpsthetic heart valve, when the poison’s ratio is0.3, the various main parameters on BHV would be superior to the other control group chosen data and its dynamic mechanical properties is at the optimal. Through analysis of different modulus of elasticity and its effect on the mechanical properties of BHV, when materials elastic modulus of BHV is chosen to1500Pa, which has best dynamic mechanics performances. Consider the BHV with different thickness on the mechanical behavior of valves analysis shows that when the valve leaflets thickness is0.54mm, the dynamic mechanical properties of BHV is at the optimal. Through the analysis of blood inlet velocity influence on mechanical performance of BHV, when the inlet velocity is lm/s, the dynamic mechanical properties of BHV is at the optimal, which better meet the clinical demand. Through the fluid-structure interaction on the dynamic analysis of the bioprosthetic heart valve, which show different parameters influence on mechanical performance of BHV in order to design and optimization, and provide important basis to improve the durability of BHV.This article uses the finite element method to analyze the dynamic mechanical performance on the fluid-structure interaction of BHV. And the results of the BHV in the stress distribution of the blood under the loading is real, which shows vital efforts to valve design and analysis, gives an important reference and experimental basis to process design, optimization and manufacture and guides important significance in the evaluation in the life and tear of BHV... |
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