摘要
目的:通过三维有限元实验方法建立模型,用来评价控制记忆合金丝(controlled memory,CM)镍钛根管锉的弯曲性能,并将其与其他相同几何形态的镍钛合金进行比较。方法:基于逆向工程技术,将21 mm长、25#/08锥度的Hyflex NT和Hyflex CM镍钛锉通过悬臂弯曲模型在距锉尖9. 5 mm处固定,力学检测仪压头在距锉尖3 mm处加载/卸载力,最大位移3 mm,得到载荷位移曲线,随后使用显微CT扫描(层间距8μm)镍钛锉,导入ABAQUS(6. 10)构建几何模型。Hyflex NT以形状记忆合金本构模型,Hyflex CM以幂硬化塑性本构模型,拟合悬臂弯曲的载荷位移曲线。结果:成功构建两个四面体单元模型,节点总数均为99 353,单元总数均为63 744。当加载位移为1 mm时,对距锉尖6. 1 mm处的横截面进行应力分布观测,上、下表面受到的弯曲应力最大,并率先进入相变屈服阶段,有限元模拟能够清楚地给出锉在变形过程中的变形特点、应力分布等各种信息,与实际实验曲线拟合度好。结论:材料本构行为对于镍钛根管锉力学行为的影响十分显著,针对CM丝镍钛根管锉的特性调试参数而建立的有限元模型能够精确地捕捉镍钛根管锉各种变形过程中的特点,且与实际实验曲线拟合度好,可用于CM丝镍钛锉弯曲性能研究。
Objective: To construct a model for a controlled memory (CM) nickel-titanium (NiTi) file and another M-wire NiTi file with the same geometry by using finite element analysis. To evaluate the flexibility of a CM NiTi file by using three dimensional finite element method and to compare its mechanical responses with that M-wire NiTi. Methods: Based on the reverse engineering, the 21 mm long, 25#/08 taper Hyflex NT NiTi file and Hyflex CM NiTi file were fixed by the cantilever bending model at a distance of 9.5 mm from the tip of the file. The mechanical tester’s indenter was loaded/unloaded at a distance of 3 mm from the tip of the file. The maximum displacement was 3 mm, the load displacement curve was obtained. Subsequently, by using a micro-CT to scan (layer spacing of 8 μm) NiTi files, and ABAQUS (6.10) was introduced to construct a geometric model. Hyflex NT was considered as a shape-memory alloy constitutive model, Hyflex CM was considered as a power-hardening plastic constitutive model, respectively. Comparing the load-displacement curve of cantilever bending in the three-dimensional finite element model with the load-displacement curve in the experiment. Results: Two tetrahedral element models were constructed, the total number of nodes was 99 353 and the total number of cells was 63 744. When the loading displacement was 1 mm, the stress distribution of the cross section at 6.1 mm from the tip of the file was observed. The upper and lower surfaces were subjected to the maximum bending stress and entered the phase transformation yield stage. The finite element simulation could clearly show the deformation of the file. Various information such as deformation characteristics and stress distribution in the process were well fitted to the actual experimental curve. Conclusion: The constitutive behavior of the material has a significant effect on the mechanical behavior of NiTi file. The finite element model established for the NiTi file of the CM wire can accurately capture the characteristics of various defo
作者
付宏宇
王芳芳
侯晓玫
FU Hong-yu;WANG Fang-fang;HOU Xiao-mei(Department of Stomatology, Peking University First Hospital, Beijing 100034, China;Department of Stomatology, Xuanwu Hospital, Capital Medical University, Beijing 100053, China;Second Clinical Division, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100101, China)
出处
《北京大学学报（医学版）》
CAS
CSCD
北大核心
2019年第1期131-135,共5页
Journal of Peking University:Health Sciences
关键词
机用镍钛锉
控制记忆镍钛锉
有限元分析
NiTi rotary file
Controlled memory NiTi file
Finite element analysis
