中国组织工程研究 ›› 2019, Vol. 23 ›› Issue (20): 3148-3152.doi: 10.3969/j.issn.2095-4344.1180

• 骨与关节生物力学 bone and joint biomechanics • 上一篇    下一篇

载荷速率对股骨颈骨折裂纹扩展影响的有限元分析

郑利钦1,林梓凌2,3,陈心敏1,梁子毅1,李木生1,郑永泽1   

  1. 1广州中医药大学第一临床医学院,广东省广州市  5104052广州中医药大学第一附属医院创伤骨科,广东省广州市  5104053广州中医药大学岭南医学研究中心,广东省广州市  510405
  • 出版日期:2019-07-18 发布日期:2019-07-18
  • 通讯作者: 林梓凌,博士,主任医师,教授,广州中医药大学第一附属医院创伤骨科,广东省广州市 510405;广州中医药大学岭南医学研究中心,广东省广州市 510405
  • 作者简介:郑利钦,男,1993年生,广东省惠州市人,汉族,广州中医药大学2017级在读硕士,主要从事骨与关节损伤的生物力学研究。

A finite element analysis of loading velocity affecting femoral neck fracture propagation

Zheng Liqin1, Lin Ziling2, 3, Chen Xinmin1, Liang Ziyi1, Li Musheng1, Zheng Yongze1   

  1. 1First School of Clinical Medicine of Guangzhou University of Chinese Medicine, Guangzhou 510405, Guangdong Province, China; 2Department of Traumatic Orthopedics, First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, Guangdong Province, China; 3Lingnan Medical Research Center of Guangzhou University of Chinese Medicine, Guangzhou 510405, Guangdong Province, China
  • Online:2019-07-18 Published:2019-07-18
  • Contact: Lin Ziling, MD, Chief physician, Professor, Department of Traumatic Orthopedics, First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, Guangdong Province, China; Lingnan Medical Research Center of Guangzhou University of Chinese Medicine, Guangzhou 510405, Guangdong Province, China
  • About author:Zheng Liqin, Master candidate, First School of Clinical Medicine of Guangzhou University of Chinese Medicine, Guangzhou 510405, Guangdong Province, China

摘要:

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文题释义:
断裂力学:材料在不断负荷作用下发生微裂纹,导致材料刚度和强度等降低,微裂纹积累到一定程度就出现裂纹扩展,继而发生大面积的裂纹,进而导致材料的折断和失效。断裂是连续的,断裂力学可直接分析构件的受力和破坏过程,因此可将脆性骨折的发生过程细化为“骨密度降低-骨小梁微损伤-裂纹拓展-微骨折-骨质断裂”的一个完整过程。
载荷速率与骨折的关系:载荷速率对松质骨的极限应力、弹性模量、破坏能及最小应力的影响,是结合了各向异性度与表面密度后的综合结果,其中与极限应力的相关性最高,其次是弹性模量、最小应力,最后才是破坏能、载荷速率对骨折裂纹的影响,实际上是载荷速率改变骨的各种材料属性后在宏观上的表现。
 
摘要
背景:骨折发生发展是个动态过程,传统有限元方法不能很好地预测及展示骨折发生的确切起点、骨质断裂过程及该过程的应力、应变、裂纹扩展情况。
目的:模拟不同跌倒载荷速率对股骨颈骨折裂纹扩展的影响。
方法:将1名健康志愿者的股骨原始CT数据导入Mimics19.0软件,经区域增长、编辑笼罩、光滑、包裹等重建股骨近端三维有限元模型,并在Hypermesh14.0中进行松质骨、皮质骨网格划分、定义材料属性、设定边界条件、模拟股骨内旋、内收位跌倒状态、加载载荷-时间函数[F1=2 500t、F2=(10 000/3)t、F3=      5 000t、F4=10 000t]等前处理,将生成的K文件导入LS-DYNA求解器中运算。
结果与结论:①骨折起始裂纹均出现在股骨颈下后方,初始裂纹长度呈载荷速率依赖性;②皮质骨断裂时的最大应力均分布在股骨颈后外侧,随着载荷速率升高,应力分布从转子间逐渐向股骨颈缩小;③股骨颈的压缩应变主要集中在股骨颈下后方,在裂纹走行处出现最大应变值;④载荷速率越高皮质骨越早发生断裂,断裂历程越短,裂纹扩展速率越高,骨折线逐渐变粗糙并上移,形成头下型骨折,同时Pauwels角也随之增大;⑤结果说明,载荷速率会改变股骨颈骨折裂纹扩展行为,进而影响髋部骨折类型。

中国组织工程研究杂志出版内容重点:人工关节;骨植入物;脊柱骨折;内固定;数字化骨科;组织工程
ORCID: 0000-0001-5241-1096(郑利钦)

关键词: 跌倒载荷速率, 股骨颈骨折, 裂纹扩展, 断裂力学, 有限元, 跌倒, CT数据, 股骨头下骨折

Abstract:

BACKGROUND: It is a dynamic development in fracture, but the traditional finite element method cannot precisely predict the fracture initiation, crack process, the stress, strain and crack propagation.

OBJECTIVE: To simulate and investigate the influence of fall load velocity on crack propagation in femoral neck fracture.
METHODS: CT data of femur from a healthy volunteer were collected and imported to Mimics 19.0 software, after region growing, editing, smoothing and wrapping, a three-dimensional finite element model of proximal femur was created. The primary model was imported in Hypermesh 14.0 for meshing of trabecular and cortical bone, defining material properties, setting boundary conditions, simulating fall in internal rotation and adduction, and loaded with load-time function (F1=2 500t; F2=(10 000/3)t; F3=5 000t; F4=10 000t). The integrated K file was finally calculated in LS-DYNA.
RESULTS AND CONCLUSION: (1) The initial crack started at the inferior-posterior of femoral neck with a velocity-dependent manner in primary length. (2) The maximum stress distributed on the inferior-posterior of femoral neck but with a negative correlation between loading velocity in distributing region from intertrochanteric to neck. (3) The compressive strain mainly demonstrated on the inferior-posterior of femoral neck that consistent with the propagation of crack. (4) Higher the loading rate was, earlier the damage began, fewer the time needed to fracture, faster the crack developed, and rougher the fracture line were and larger the Pauwels angle formed. (5) In summary, fall loading rate is an important exogenous factor in femoral neck fracture propagation, which affects hip fracture types.

Key words: fall load velocity, femoral neck fracture, crack propagation, fracture mechanics, finite element, fall, CT data, subfemoral fracture

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