“V”型寰枢椎复位内固定器的有限元力学模型分析

The Finite Element Modeling and Mechanical Analysis of "V"-type Atlantoaxial Reduction and Internal Fixation

目的建立新型寰枢椎复位内固定器的三维有限元模型,并对其进行生物力学分析。方法运用Pro/E 2001和MSC.Patran 2005软件,根据Ni-Ti合金寰枢椎复位内固定器和п型固定钉的设计参数,建立复位器有限元模型,部位约束后给以100N力学加载后计算区域受力的节点范围。结果所建模型外观逼真、几何相似性好,形变应力场主要集中在复位器V型尖端与稳定臂折弯处,其最大应力强度为4.78MPa,有2794个节点范围;V型翼的锐角交汇点处所承受的应力强度次之,达0.31MPa,有1953个节点范围;V型翼的末端受力最小,为1.22×10-3MPa,有1730个节点范围。п形固定钉的应力集中在钉齿中央部位和钉齿尖端两侧,最大应力强度为1.68×10-2MPa,有1146个节点范围。结论复位固定器加载后恢复形变时的受力情况和力学特征完全与Ni-Ti合金材料的形状记忆功能和超弹性特征相适应,能够满足临床需要。

ObjectiveTo establish a three-dimensional finite element model and make mechanical analysis of “V”-type atlantoaxial reduction and internal fixation. MethodsAccording to “V”-type atlantoaxial and internal fixation,based on screw-type Ⅱ design parameters, and using Pro/E 2001 and MSC.Patran 2005 software, we set up a finite element model and calculated the region containing the node scope of the force as the sites binding and 100N mechanics adding. ResultsThe model looked realistic, geometric similarity.The deformation stress field mainly concentrated in the reset device V-tip arm bending and stability.The strength of its maximum stress was 4.78MPa,and the scope had 2794 nodes.V-type wing of the acute angle point of convergence of the premises to bear the stress intensity followed.It was 0.31MPa,and the scope had 1953 nodes.V-type wing by the end of edge was the smallest for the 1.22×10^-3MPa,and there was the scope of 1730 nodes. Ⅱ-shaped fixed nail stress concentrated at the central parts of tooth and the art on both sides of teeth,with maximum stress intensity of 1.68×10^-2MPa,and there was the scope of 1146 nodes. ConclusionThe reduction and fixation devices to load at the time of recovery deformation forces and mechanical characteristics adapted to Ni-Ti shape memory alloy material functions and super-elasticity completely,which meets the clinical needs.