金属背衬变形对陶瓷陶瓷人工全髋关节接触力学的影响-硕士毕业论文.docx

1、硕士学位论文金属背衬变形对陶瓷/ 陶瓷人工全髋关节接触力学的影响学位申请人：指导教师：教授学科名称：机械工程年 月摘 要I论文题目：金属背衬变形对陶瓷/陶瓷人工全髋关节接触力学的影响学科名称：机械工程学位申请人：指导教师：教授摘 要目前人工髋关节假体是治疗髋关节疾病的比较有效的手段并且得到临床的广泛应用。随着髋关节病患者的年轻化以及对髋关节假体寿命要求的不断提高，非骨水泥型陶瓷对陶瓷髋关节假体得到越来越广泛的应用。非骨水泥髋关节是通过假体与盆骨髋臼窝之间的过盈配合来保证其初始的稳定性，随后背衬与髋臼窝界面之间会产生骨长入以确保假体长期的稳定可靠性。然而压配会造成金属背衬的变形，这也可能会对内衬

2、的变形造成影响，随之影响关节的接触力学性能。本研究建立了显式动态有限元仿真模型来研究金属背衬变形对非骨水泥陶瓷对陶瓷人工全髋关节假体接触力学的影响。本研究发现，在金属背衬与髋臼窝之间存在 1 mm 直径干涉量的条件下，对于 32 mm 球头，陶瓷内衬在植入金属背衬内表面时，产生了 31 m 的直径变形量，相应地，产生了 144 MPa 的最大主应力（拉应力） ，加载之后变形量以及最大拉应力分别增加至 52 m、245 MPa 。本研究结果表明，降低陶瓷内衬的厚度会引起陶瓷内衬的变形量增加，当厚度由8 mm 降为 6 mm 时最大拉应力约增加两倍，而当陶瓷内衬由 6 mm 降低至 5 mm 时所

3、产生的拉应力会有些许降低，但是其变化较小（不大于 4%） ；增加金属背衬的厚度（3 mm 至 8 mm）会降低陶瓷内衬的变形，从而会降低在陶瓷内衬产生的最大拉应力（降低量达到 41%） ，能够提高陶瓷关节的安全性能；当金属背衬的弹性模量由 110 GPa 降低至 40 GPa 时，对陶瓷内衬的变形以及最大拉应力的影响较小（不大于 4%） ，进而不会影响关节的安全性；针对不同年龄段病患者（骨密度 1 g/cm3 至 1.8 g/cm3） ，骨密度增大会引起陶瓷内衬的变形量增加，应力增加了 127%；对于临床中的髋臼窝打磨误差，当误差造成金属背衬与髋臼窝之间的干涉量增加时，其误差会引起最大拉应力的

4、增加，干涉量达到 2 mm 时，会产生 297 MPa 的拉应力，对陶瓷内衬的安全性造成不利的影响。本研究对于临床有重要的指导意义。临床医生应当避免髋臼窝打磨误差的发生；对于骨密度较大的病患者，应当降低金属背衬与髋臼窝之间的干涉量；适宜选择较厚的金属背衬与较薄的陶瓷内衬相配合，可以降低陶瓷关节失效的可能性。同时，应当更青睐于较小弹性模量的金属背衬，不仅不会影响陶瓷内衬的接触力学，还能降低应力遮挡效应，降低骨溶解。西安交通大学硕士学位论文II关键词：陶瓷对陶瓷髋关节假体；压配；变形；显式动态有限元；接触力学 论文类型：应用基础ABSTRACTTitle: The Influence of Pre

5、ss-fit Deformation of Metal-backing Shell on Contact Mechanics of Ceramic-on-ceramic THADescipline: Mechanical EngineeringApplicant: Changdong QiuSupervisor: Prof. Zhongmin JinABSTRACTTotal hip arthroplasty (THA) of ceramic-on-ceramic (COC) bearing combinations is increasingly used clinically. The m

6、ajority of these implants are used with cementless fixation that a metal-backing shell is press-fitted into the pelvic bone. This usually results in the deformation of the metallic shell, which may also influence the ceramic liner deformation and consequently the contact mechanics between the liner

7、and the femoral head under loading.The explicit dynamic finite element method was applied to model the implantation of a cementless COC with a titanium shell and subsequently to investigate the effect of the metallic shell deformation on the contact mechanic of ceramic-on-ceramic THA. The maximum de

8、formation and the maximum principal stress of the ceramic liner were 31 m and 144 MPa (tensile stress) respectively after it was inserted into the shell and further increased to 52 m and 245 MPa under loading with a 1 mm diameter interference. This research highlights the importance of the press-fit

9、 of the metallic shell on the contact mechanics of the ceramic liner for ceramic-on-ceramic THAs and potential clinical performances.The research shows that the ceramic liner deformation would increase with the decrease of the thickness of the ceramic liner. The ceramic liner would produce two times

10、 larger tensile stress when the thickness decreased from 8 mm to 6 mm thickness liner. The stress would had a small degree of reduction (less than 4%) when the thickness was reduced to 5 mm. The tensile stress generated in ceramic liner would have a 41% decrease when the thickness of the metal-backi

11、ng shell increased from 3 mm to 8 mm,which would improve the joint safety performance. Whats more, the ceramic liner deformation and the contact mechanism would not be affected by elastic modulus of the metal-backing shell (40 GPa to 110 GPa). For 西安交通大学硕士学位论文IVdifferent degree of the bone miner den

12、sity (1 g/cm3 to 1.8 g/cm3), the increase of the bone density would cause the ceramic liner deformation increase and caused 127% larger tensile stress, respectively. For clinical reamer error, the error that caused the interference increased would induce larger tensile stress (297 MPa for 2 mm inter

13、ference) and increased the possibility of the failure.This research highlights the importance of the press-fit of the metallic shell on the contact mechanics of the ceramic liner for ceramic-on-ceramic THAs and potential clinical performances. The reamer error should be avoided for the bearing conta

14、ct mechanism and the initial stability of the ceramic-on-ceramic THAs. For larger bone density patients, the interference should be reduced. The thick metal-backing shell and the thin ceramic liner would be a comparatively ideal assembly that would greatly reduce the possibility of the failure of th

15、e THAs. Furthermore, the lower elastic modulus of the Ti-alloy backing shell should be recommended, not only for no influence on the contact mechanism but also for the reduction of the stress shielding.KEY WORDS: Ceramic-on-ceramic THA; Press fit; Deformation; Explicit finite element; Contact mechan

16、icsTYPE OF THESIS: Application Foundamentals目 录V目 录1 绪论 .11.1 选题意义及应用背景 .11.2 国内外研究现状分析 .21.2.1 髋臼杯变形的实验研究现状 .21.2.2 髋臼杯变形以及接触力学的有限元仿真研究现状 .41.3 论文研究内容 .71.4 技术路线 .92 全髋关节模型有限元方法的建立 .102.1 金属背衬敲入臼窝模型的建立 .102.1.1 表面置换模型 .102.1.2 变形结果对比分析 .132.2 全髋关节置换模型的建立 .152.2.1 全髋关节有限元模型 .152.2.2 全髋关节接触力学 .192.2.

17、3 讨论 .222.3 二维陶对陶关节接触力学 .232.3.1 陶对陶关节模型 .232.3.2 仿真结果 .242.3.3 讨论 .262.4 全髋关节有限元方法验证 .272.4.1 有限元方法验证模型 .282.4.2 实验与仿真结果对比 .312.4.3 有限元模型的有效性分析 .332.5 本章小结 .333 陶瓷髋关节假体接触力学 .353.1 陶瓷对陶瓷髋关节接触力学 .353.1.1 三维陶瓷关节假体模型 .353.1.2 陶瓷对陶瓷接触力学 .373.1.3 接触力学分析 .413.2 本章小结 .424 陶瓷关节接触力学影响因素研究 .43西安交通大学硕士学位论文VI4.

18、1 陶瓷内衬厚度对接触力学的影响 .434.1.1 内衬厚度模型 .444.1.2 不同内衬厚度模型结果对比 .444.1.3 内衬厚度对接触力学影响讨论 .464.2 金属背衬厚度对接触力学的影响 .474.2.1 背衬厚度模型 .474.2.2 不同背衬厚度模型结果对比 .484.2.3 背衬厚度对接触力学影响的讨论 .504.3 髓腔锉打磨误差对接触力学的影响 .504.3.1 打磨误差模型 .514.3.2 打磨误差模型结果对比 .514.3.3 打磨误差对接触力学影响的讨论 .544.4 病人骨密度对接触力学的影响 .554.4.1 骨密度模型 .554.4.2 不同骨密度模型结果对

19、比 .554.4.3 骨密度对接触力学影响的讨论 .584.5 金属背衬材料的影响 .584.5.1 背衬材料 .594.5.2 背衬材料模型结果对比 .594.5.3 背衬弹性模量对接触力学影响的讨论 .614.6 本章小结 .615 结论与展望 .625.1 结论 .625.2 展望 .63致 谢 .64参考文献 .65攻读学位期间取得的研究成果 .70声明CONTENTSVIICONTENTS1 Preface.11.1 Research Background and Significance.11.2 Research Status .21.2.1 Experiment Researc

20、h Status of Acebabular Cup Deformation.21.2.2 FEA Research Status of Cup Deformation and Contact Mechanics.41.3 Research Content .71.4 Technical Route .92 FEA Method Establishment of Cemnetless THA.102.1 Backing-shell Impacted.102.1.1 Resurfacing Model.102.1.2 Deformation Comparasion.132.2 Establish

21、ment of THA FEA Model .152.2.1 THA Model.152.2.2 Contact Mechanics of THA .192.2.3 Discussion .222.3 Two-Dimension Model of Ceramic-on-Ceramic.232.3.1 Ceramic-on-Ceramic Model .232.3.2 FEA results.242.3.3 Contact Mechanics Analysis.262.4 Method Validation .232.4.1 Validation Model .282.4.2 Comparasi

22、on of Experiment and FEA Results .312.4.3 Validity Analysis.332.5 Chapter Summary .343 Contact Mechanics of Ceramic-on-Ceramic.353.1 Three-Dimension Model .353.1.1 Three-Dimension Model .353.1.2 Contact Mechanics.373.1.3 Discussion .403.2 Chapter Summary .42西安交通大学硕士学位论文VIII4 Influence Factors Study on Ceramic THA Contact Mechanics.434.1 Influence of Ceramic Liner Thickness on Contact Mechanics .434.1.1 Thickness Model.444.1.2