Exponential model for the tensile true stress-strain behavior of as-irradiated and oxidatively degraded ultra high molecular weight polyethylene.
Exponential model for the tensile true stress-strain behavior of as-irradiated and oxidatively degraded ultra high molecular weight polyethylene.
复制标题
辐照和氧化降解超高分子量聚乙烯拉伸真实应力应变行为的指数模型。
DOI：
10.1002/jor.1100140512
复制
发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Bartel,DL
中科院分区：
文献类型：
--
作者：
Kurtz,SM;Rimnac,CM;Santner,TJ;Bartel,DL
伽马辐照灭菌后，用于全关节置换术的超高分子量聚乙烯组件在暴露于空气和体内环境后发生氧化降解。氧化降解伴随着密度的增加。本研究的主要目的是开发一种数学模型，以预测这些灭菌组件的单调拉伸力学行为，作为氧化降解引起的密度变化的函数。超高分子量聚乙烯的拉伸试样用γ射线灭菌，然后在空气炉中氧化降解。使用密度梯度柱测量每个样品的平均密度。对选定的样本进行差示扫描量热法和傅里叶变换红外光谱法，以表征加速老化与环境货架老化引起的物理和化学变化。在单调单轴拉伸下进行力学测试。将指数模型拟合至真实应力-应变数据（真实应变高达0.12）。观察到的拟合应力的相关系数为0.996。该模型允许定量预测超高分子量聚乙烯组件的真实应力-应变曲线与密度之间的关联。所提出的指数模型有效地描述了辐照和氧化降解超高分子量聚乙烯组件的大应变单调拉伸行为的变化。
Following sterilization by gamma radiation, ultra high molecular weight polyethylene components for total joint replacement undergo oxidative degradation upon exposure to air and thein vivoenvironment. Oxidative degradation is accompanied by an increase in density. The primary objective of this study was to develop a mathematical model to predict the monotonic tensile mechanical behavior of these sterilized components as a function of changes in density arising from oxidative degradation. Tensile specimens of ultra high molecular weight polyethylene were sterilized with gamma radiation and then oxidatively degraded in an air furnace. The average density of each specimen was measured using a density gradient column. Differential scanning calorimetry and Fourier transform infrared spectroscopy were conducted on selected specimens to characterize the physical and chemical changes due to accelerated aging as opposed to ambient shelf aging. Mechanical testing was conducted in monotonic uniaxial tension. An exponential model was fitted to the true stress‐strain data (up to a true strain of 0.12). The observed fitted stress had a correlation coefficient of 0.996. The model permits a quantitative prediction of the association between the true stress‐strain curve and density for the ultra high molecular weight polyethylene components. The proposed exponential model effectively describes changes in the large‐strain monotonic tensile behavior of as‐irradiated and oxidatively degraded ultra high molecular weight polyethylene components.