偏心对镍钛锉力学性能和容屑率的影响分析

Effect of Eccentricity on the Mechanical Properties of NiTi File and the Chip Rate Analysis

在相同载荷条件下,研究偏心和截面形状对镍钛根管器械弯曲刚度和最大Vos-mises应力的影响。通过三维软件建立4种截面形状(正三角形、细矩形、矩形、正方形)下的3种偏心度(0、10%、20%)共12个有限元模型,采用超弹性镍钛合金材料进行实验模拟。先让器械尖部偏转4mm,再让器械绕中心轴线旋转360゜,分析器械在模拟中的Vos-mises应力分布状况并计算弯曲刚度。正方形截面的弯曲刚度和最大Vos-mises应力最大,细矩形截面最小。偏心会降低器械的弯曲刚度和最大Vos-mises应力,提高使用寿命和容屑率。在截面不变时,偏心截面器械比未偏心截面器械具有更优的机械性能。因此在优化器械机械性能上,有很大的潜力。

Under the same load conditions, three kinds of eccentricity nickel-titanium instruments under four sections were compared to study the effects of eccentricity and cross-sectional shape on the bending stiffness and maximum Vos-mises stress of the instrument. Three finite element models of three eccentricities(0, 10%, 20%) under four cross-sectional shapes(normal triangle, thin rectangle, rectangle, square) were established by three-dimensional software, and superelastic nickel-titanium alloy materials were used. Perform an experimental simulation. First deflect the tip of the instrument by 4 mm, then rotate the instrument 360゜ around the central axis to analyze the Vos-mises stress distribution and calculate the bending stiffness of the instrument during the simulation. The bending stiffness and maximum Vos-mises stress of the square section are the largest, and the thin rectangular section is the smallest. Eccentricity reduces the bending stiffness and maximum Vos-mises stress of the instrument, increasing service life and chipping rate. Eccentric cross-section instruments have better mechanical properties than unbiased cross-section instruments when the cross-section is constant. Therefore, there is great potential in optimizing the mechanical properties of the device.