人工心瓣关闭瞬间的水击现象和水弹性分析

On the Water Hammer Phenomenon and Hydroelasticity Analysis at the Instent of Valve Prostheses Closure

本文首先评述了人工心瓣可靠性的现状。接着研究了人工心瓣的水击现象．推导了水击的有关公式，讨论了影响水击的因素．并用算例．计算了典型人工心瓣的峰值跨瓣压力梯度ＰＰＧ；最后作者将血液和心瓣作为一个固液耦合系统．对刚关闭后瞬间进行了水弹性有限元分析。将水击跨瓣压力梯度作为一个突加载荷引入。通过算例计算表明，在０．１２ｍｓ以后．机械瓣中心所受冲击力．相当于所施加载荷的２倍。

In this paper,first of all, we evaluate reliable condition of valve prostheses.Secondly,we investigate water hammer phenomenon and derive some formulas,discuss influence element of water hammer.Thirdly,we compute peak pressure gradient accros valve.At last,we use finite element method to analysis hydroelasticity of blood/mechanical valve system when valve is at closing position.The water hammer peak pressure gradient accros valve as a suddenly applied load is introduced.The computing results show that after the 0.12ms.impulsive force of center in mechanical valve is egual to twice the applied load.