北京生物医学工程

主动脉弓周向应力的非线性数值研究

Nonlinear Numerical Study on Circumferential Stress of Aortic Arch

作者：李坤李晓阳

单位：北京工业大学机电学院（北京100124）

分类号：

出版年·卷·期（页码）：2010·29·5（497-502）

摘要：

目的利用非线性数值计算模型研究人体主动脉弓的周向应力分布状态，为临床治疗主动脉弓夹层提供生物力学依据。方法在有限元软件ANSYS中建立主动脉弓的简化模型，采用非线性M-R两参数模型定义材料物理性质，计算得出非线性模型上6个特定截面上的周向应力数值，分析周向应力分布及变化趋势，并与应用线弹性模型的计算结果作对比。结果与应用线弹性模型比较，利用非线性模型得到的不同截面的周向应力分布有很大差异；在弯管段同一截面的不同方向上的周向应力分布也不相同；非线性模型的应力变化趋势和线弹性模型的基本相同，但应力水平低于线弹性模型。结论材料非线性会对主动脉弓的周向应力分布产生较大影响。

Objective To study the circumferential stress distributions of human’s aortic arch by a nonlinear numerical calculation model and provide the biomechanical basis for treating the disease of aortic dissection in clinic. Methods After building the simplified model of aortic arch using ANSYS, the circumferential stress values on six particular sections of nonlinear model were obtained, using a nonlinear two-parameter model which is one of M-R model to define physical properties of material, aiming at analyzing the characteristic of circumferential stress in nonlinear model and comparing with elastic model.Results The circumferential stress distributions of six sections in nonlinear model were great different from those of linear model. In the nonlinear model, the circumferential stresses among different directions were different at same section in the bend tube. However, along with the tube, the change tendency of stress distribution in nonlinear model was nearly same as that of linear elastic model, and the value level of stress was lower than the linear model’s.Conclusion The material nonlinearity strongly affects the distribution of circumferential stress.

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