人体主动脉弓周向应力的非线性数值模型研究

Nonlinear numerical model analysis of circumferential stress on human aortic arch

目的为了解主动脉弓的受力状况,选择适当的本构关系,为进一步分析人体主动脉弓的生物力学特性提供参考依据,并为临床治疗主动脉弓夹层瘤提供生物力学依据。方法使用有限元方法分析了两种约束条件(第1种约束条件:沿升主动脉管轴方向的约束;第2种约束条件:升主动脉端可自由运动,但端部用半球封闭)的3种本构关系(线性本构、指数函数本构和M-R两参数本构)在两种载荷(10.67 kPa和26.66 kPa)下主动脉弓模型的周向应力,并对计算结果进行探讨。结果建立了两种约束条件下的模型,并分别得出了在这两种约束条件下的3个本构关系在两种载荷下主动脉弓的周向应力的云图和周向应力沿弧长的分布。结论指数函数本构关系可以较全面地反映主动脉弓血管的物理属性。第2种约束条件能够更真实地反映主动脉弓的物理特性。

Objective To provide reference for understanding the stress state of the aortic arch,select the appro-priate constitutive relation,further analyze the biomechanical properties of human aortic arch so as to offer the bi-omechanical basis for treating aortic arch in clinic.Method Under two different constraints（the first constraint： the constraint along with the direction of ascending aorta;the second constraint： the ascending aorta could move freely,but the end was closed with a hemisphere）,three constitutive relationships（linear constitutive,exponen-tial function constitutive,M-R constitutive） and two loads（10.67 kPa and 26.66 kPa）,the circumferential stress on human aortic arch were studied by the finite element method,and the results were also discussed.Results The models under two constraints were established and the contour plot of circumferential stress and its distribu-tion along the arc of aortic arch under two constraints,three constitutive relationships and two loads were obtained respectively.Conclusions The exponential function constitutive model could reflect the mechanical properties of aortic arch more comprehensively and the mechanical properties of aortic arch could be reflected more factually under the second constraint.