Analysis of anisotropic viscoelastoplastic properties of cortical bone tissues
Analysis of anisotropic viscoelastoplastic properties of cortical bone tissues
复制标题
DOI：
10.1016/j.jmbbm.2010.10.001
复制
发表时间：
2011-07-01
影响因子：
3.9
通讯作者：
Silberschmidt, Vadim V.
中科院分区：
文献类型：
--
作者：
Abdel-Wahab, Adel A.;Alam, Khurshid;Silberschmidt, Vadim V.
骨折影响许多人的健康，并具有显著的社会和经济影响。通常，骨折是由于撞击、突然的福尔斯摔倒或外伤。为了数值模拟骨折的皮质骨组织所造成的影响，重要的是要知道参数表征其粘弹塑性行为。这些参数应在骨组织中的各种方向上测量，以评估与其微观结构相关的骨的各向异性。因此，本研究的第一部分重点是使用沿沿着与骨轴纵向（轴向）和横向相关的不同方向切割的标本定量皮质骨的弹塑性行为。由于显着的非线性的弹塑性行为的组织，循环加载-卸载单轴拉伸试验进行，以获得的弹性模量的大小，不仅从初始加载部分的周期，但也从其卸载部分。在不同的变形率下进行了额外的测试，以研究骨的应变率敏感性。本研究的第二部分涵盖了两个方向和四个不同的解剖位置-前，后，内侧和外侧-皮质骨的蠕变和松弛特性，以研究骨的属性的变异性。由于粘弹塑性的皮质骨影响其阻尼性能，由于能量耗散，动态力学分析（DMA）技术被用于在我们的研究的最后一部分，以获得不同频率的存储和损耗模量的大小。基于对牛皮质骨组织的弹塑性行为的分析，发现四个皮质位置的纵向杨氏模量的大小在15-24 GPa的范围内，而横向模量在10和15 GPa之间较低。不同解剖位置的轴向强度也高于横向强度，这些位置的幅度存在显著差异。蠕变和松弛试验中获得的定量数据没有表现出显着的位置特定的差异。DMA结果表明，由于牛皮质骨的粘度具有0.035-0.1范围内的损耗因子，因此能量损耗能力相对较低。(C)2010爱思唯尔有限公司版权所有。
Bone fractures affect the health of many people and have a significant social and economic effect. Often, bones fracture due to impacts, sudden falls or trauma. In order to numerically model the fracture of a cortical bone tissue caused by an impact it is important to know parameters characterising its viscoelastoplastic behaviour. These parameters should be measured for various orientations in a bone tissue to assess bone's anisotropy linked to its microstructure. So, the first part of this study was focused on quantification of elastic-plastic behaviour of cortical bone using specimens cut along different directions with regard to the bone axis longitudinal (axial) and transverse. Due to pronounced non-linearity of the elastic-plastic behaviour of the tissue, cyclic loading-unloading uniaxial tension tests were performed to obtain the magnitudes of elastic moduli not only from the initial loading part of the cycle but also from its unloading part. Additional tests were performed with different deformation rates to study the bone's strain-rate sensitivity. The second part of this study covered creep and relaxation properties of cortical bone for two directions and four different anatomical positions - anterior, posterior, medial and lateral - to study the variability of bone's properties. Since viscoelastoplasticity of cortical bone affects its damping properties due to energy dissipation, the Dynamic Mechanical Analysis (DMA) technique was used in the last part of our study to obtain magnitudes of storage and loss moduli for various frequencies. Based on analysis of elastic-plastic behaviour of the bovine cortical bone tissue, it was found that magnitudes of the longitudinal Young's modulus for four cortical positions were in the range of 15-24 GPa, while the transversal modulus was lower between 10 and 15 GPa. Axial strength for various anatomical positions was also higher than transversal strength with significant differences in magnitudes for those positions. Quantitative data obtained in creep and relaxation tests exhibited no significant position-specific differences. DMA results demonstrated relatively low energy-loss capability due to viscosity of bovine cortical bone that has a loss factor in the range of 0.035-0.1. (C) 2010 Elsevier Ltd. All rights reserved.