摘要
背景:目前已有股骨柄数值计算与实验标准所用的模型与加载方式还不一致。现在使用的股骨柄有限元计算标准ASTM F2996-2013/YY/T 17142020规定了髋关节股骨柄假体的计算模型为单一的股骨柄,加载方式为刚性区加载;实验标准YY/T 0809.6-2018/ISO 7206:2013规定的模型则包括股骨柄、球头和压板,加载方式为位移加载。由于计算模型和实验模型的不同导致了计算结果与实验结果相差较大,而当计算模型与实验模型一致时且加载方式相同时,二者结果的差值明显减小。这表明采用ASTM F2996-201/YY/T 17142020标准的计算模型和加载方式还存在明显缺陷。目的:研究不同加载方式对股骨柄头颈部应力分布的影响,减少计算结果和实验结果的误差,用球头压板模型和位移加载方式替代现有股骨柄数值计算的标准,提高计算精度。方法:①数值模拟:通过有限元分析软件ANSYS APDL对单一股骨柄和股骨柄球头压板2种计算模型分别采用刚性区加载和位移加载,得到2种模型和不同加载方式下股骨柄头颈部的应力分布规律;②电测实验:利用球头压板对股骨假体柄施加载荷通过在柄颈部贴应变片得到应变数值;③比较计算结果和实验结果,确定与实验结果接近的计算模型和加载方法。结果与结论:①股骨柄球头压板模型在位移加载方式下,股骨假体柄的颈部应力峰值为504 MPa,最大拉应力主要集中在头颈部外侧,最大压应力主要集中在头颈部内侧;②单一股骨柄模型在刚性区加载方式下,股骨假体柄的颈部应力峰值为562 MPa,最大拉应力主要集中在头颈部外侧,最大压应力主要集中在头颈部内侧,应力分布规律与位移加载方式接近;③电测实验显示,头颈部内侧应变值为-581.96με,头颈部外侧应变值为666.00με;④与应变片相对应位置位移加载方式下的内侧应变值为-834.91με,外侧应变值为724.32με;刚性区加载方式下内侧应变值为-992.32με,外侧应变值1006.97με;⑤提示采用股骨柄球头压板模型和位移加载方式的结果更接近实验结果,应该作为股骨柄有限元计算的标准。
BACKGROUND:At present,the model and loading mode used in the numerical calculation of the femoral stem are not consistent with the experimental standard.The current finite element calculation standard of the femoral stem,ASTM F2996-2013/YY/T 17142020,specifies that the computational model for the femoral stem prosthesis of the hip joint is a single femoral stem,and the loading mode is the rigid zone loading.The model specified in the experimental standard YY/T 0809.6-2018/ISO7206:2013 includes femoral stem,ball head and platen,and the loading mode is displacement loading.Inconsistency between computational and experimental models leads to a large difference between the calculation and experimental results.When the computational model is consistent with the experimental model and the same loading mode is used in the two models,the difference between the two model results is significantly reduced.This indicates that the computational model and its loading mode designed based on ASTM F2996-2013/YY/T 17142020 still have obvious defects.OBJECTIVE:To investigate the effect of different loading modes on stress distribution in the head and neck of the femoral stem,reduce the error of calculation results and experimental results,and replace the existing standard of numerical calculation of the femoral stem by the ball head pressing plate model and displacement loading mode,thereby improving the calculation accuracy.METHODS:Numerical simulation:The rigid zone loading and displacement loading were applied to the two computational models of single femur stem and femur stem ball head pressing plate by using the finite element analysis software ANSYS APDL,respectively,to obtain the law of stress distribution in the head and neck of the femoral stem under the two models and different loading modes.Electrical testing:the strain value was obtained through a strain sheet attached at the stem neck when the femoral prosthesis stem was loaded by the ball head pressing plate.The computational model and loading mode close to the experimental results were determined by comparing the calculation results with the experimental results.RESULTS AND CONCLUSION:The femoral stem ball head pressing plate model showed a stress peak of 504 MPa at the neck of the femoral stem under displacement loading mode.The maximum tensile stress was mainly concentrated on the lateral head and neck,and the maximum compressive stress was mainly concentrated on the medial head and neck.The single femoral stem model showed a stress peak of 562 MPa at the neck of the femoral stem under the rigid zone loading.The maximum tensile stress was mainly concentrated on the lateral head and neck,the maximum compressive stress was mainly concentrated on the medial head and neck,and the stress distribution law was close to that of the displacement loading mode.In the electrical testing,the strain value was-581.96μεon the medial head and neck and 666.00μεon the lateral head and neck.The inner strain value was-834.91μεand the outer strain value was 724.32μεunder the displacement loading mode corresponding to the position of strain sheet.Under the rigid zone loading,the inner strain value was-992.32με,and the outer strain value was 1006.97με.To conclude,the results of the ball head pressing plate model and the displacement loading mode are relatively close to the experimental results and should be used as the standard for the finite element calculation of the femur stem.
作者
谢菲
贾鹏
刘佳辛
刘璐
张春秋
叶金铎
Xie Fei;Jia Peng;Liu Jiaxin;Liu Lu;Zhang Chunqiu;Ye Jinduo(Tianjin Key Laboratory of Advanced Mechanical and Electrical System Design and Intelligent Control,National Experimental Teaching Demonstration Center of Mechanical and Electrical Engineering,School of Mechanical Engineering,Tianjin University of Technology,Tianjin 300384,China;Tianjin Hospital,Tianjin 300350,China;Tianjin Key Laboratory of Bone Implant Interface Functionalization and Personality Research,Just Huajian Medical Equipment(Tianjin)Co.,Ltd.,Tianjin 300190,China)
出处
《中国组织工程研究》
CAS
北大核心
2022年第15期2302-2306,共5页
Chinese Journal of Tissue Engineering Research
基金
天津市科技支撑重点项目(18YFZCS00890),项目负责人:刘璐
天津市科技计划项目生物医学工程科技重大专项(18ZXSGSY00010),项目参与人:刘璐
天津市重点实验室开放基金(SY-04-201902-003),项目参与人:贾鹏
天津市重点实验室开放基金(SY-04-201901-003),项目负责人:贾鹏。
关键词
股骨柄头颈部
刚性区加载
位移加载
应力
应变
femoral stem head and neck
rigid zone loading
displacement loading
stress
strain