Prediction of multiaxial mechanical behavior for conventional and highly crosslinked UHMWPE using a hybrid constitutive model
Prediction of multiaxial mechanical behavior for conventional and highly crosslinked UHMWPE using a hybrid constitutive model
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DOI：
10.1016/s0142-9612(02)00514-8
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发表时间：
2003-04-01
期刊：
影响因子：
14
通讯作者：
Kurtz, SM
中科院分区：
文献类型：
--
作者：
Bergström, JS;Rimnac, CM;Kurtz, SM
关节置换术中使用的超高分子量聚乙烯（UHMWPE）的理论失效、疲劳和磨损模型的开发一直受到阻碍，因为缺乏经验证的本构模型，该模型可准确预测临床相关多轴载荷条件下的大变形力学行为。最近，Bergstrom等人开发了一种新的未辐照UHMWPE混合本构模型，（Biomaterials 23（2002）2329）基于物理学驱动的框架，其将聚合物的支配微观机制并入有效且准确的连续体表示中。本研究的目的是比较新混合模型与J（2）-塑性模型在多轴载荷过程中对四种传统和高交联UHMWPE材料的预测能力。在单轴载荷下校准后，通过将来自实验多轴（小冲杆）测试的载荷-位移曲线与使用实验装置的有限元模型计算的模拟载荷-位移曲线进行比较来测试J（2）-塑性和混合模型的预测能力。使用决定系数（r（2））量化模型预测的质量。研究结果表明，Hybrid模型在单轴拉压联合预测和模拟小冲杆试验产生的多轴大变形力学行为方面均优于J（2）-塑性模型。结果进一步表明，基于与弹性模量、屈服应力、应变硬化率和聚合物链锁定拉伸相关的四种材料特性的表征，HM的参数可推广到各种常规、高度交联和热处理的UHMWPE材料。最重要的是，从实用的角度来看，混合本构模型的这四个关键材料特性可以通过相对简单的单轴拉伸或压缩试验来测量。(C)2002爱思唯尔科技有限公司版权所有。
The development of theoretical failure, fatigue, and wear models for ultra-high molecular weight polyethylene (UHMWPE) used in joint replacements has been hindered by the lack of a validated constitutive model that can accurately predict large deformation mechanical behavior under clinically relevant, multiaxial loading conditions. Recently, a new Hybrid constitutive model for unirradiated UHMWPE was developed Bergstrom et al., (Biomaterials 23 (2002) 2329) based on a physics-motivated framework which incorporates the governing micro-mechanisms of polymers into an effective and accurate continuum representation. The goal of the present study was to compare the predictive capability of the new Hybrid model with the J(2)-Plasticity model for four conventional and highly crosslinked UHMWPE materials during multiaxial loading. After calibration under uniaxial loading, the predictive capabilities of the J(2)-plasticity and Hybrid model were tested by comparing the load-displacement curves from experimental multiaxial (small punch) tests with simulated load-displacement curves calculated using a finite element model of the experimental apparatus. The quality of the model predictions was quantified using the coefficient of determination (r(2)). The results of the study demonstrate that the Hybrid model outperforms the J(2)-plasticity model both for combined uniaxial tension and compression predictions and for simulating multiaxial large deformation mechanical behavior produced by the small punch test. The results further suggest that the parameters of the HM may be generalizable for a wide range of conventional, highly crosslinked, and thermally treated UHMWPE materials, based on the characterization of four material properties related to the elastic modulus, yield stress, rate of strain hardening, and locking stretch of the polymer chains. Most importantly, from a practical perspective, these four key material properties for the Hybrid constitutive model can be measured by relatively simple uniaxial tension or compression tests. (C) 2002 Elsevier Science Ltd. All rights reserved.