Department of Mechanical and Materials Engineering, McLaughlin Hall 305, Queen's University, Kingston, Ontario, Canada.
J Biomech. 2009 Nov 13;42(15):2520-7. doi: 10.1016/j.jbiomech.2009.07.008. Epub 2009 Aug 3.
Experimental wear testing is an essential step in the evaluation of total knee replacement (TKR) design. Unfortunately, experiments can be prohibitively expensive and time consuming, which has made computational wear simulation a more desirable alternative for screening designs. While previous attempts have demonstrated positive results, few models have fully incorporated the affect of strain hardening (or cross shear), or tested the model under more than one loading condition. The objective of this study was to develop and evaluate the performance of a new holistic TKR damage model, capable of predicting damage caused by wear, including the effects of strain hardening and creep. For the first time, a frictional work-based damage model was compared against multiple sets of experimental TKR wear testing data using different input kinematics. The wear model was tuned using experimental measurements and was then able to accurately predict the volumetric polyethylene wear volume during experiments with different kinematic inputs. The size and shape of the damage patch on the surface of the polyethylene inserts were also accurately predicted under multiple input kinematics. The ability of this model to predict implant damage under multiple loading profiles by accounting for strain hardening makes it ideal for screening new implant designs, since implant kinematics are largely a function of the shape of the components.
实验磨损测试是评估全膝关节置换术（TKR）设计的重要步骤。不幸的是，实验可能非常昂贵且耗时，这使得计算磨损模拟成为筛选设计的更理想替代方法。虽然以前的尝试已经取得了积极的结果，但很少有模型完全考虑了应变硬化（或交叉剪切）的影响，或者在超过一种加载条件下测试模型。本研究的目的是开发和评估一种新的整体 TKR 损伤模型的性能，该模型能够预测由磨损引起的损伤，包括应变硬化和蠕变的影响。首次使用基于摩擦功的损伤模型，使用不同的输入运动学，比较了多组实验 TKR 磨损测试数据。使用实验测量对磨损模型进行了调整，然后可以根据不同的运动学输入准确预测实验过程中的聚乙烯磨损体积。在多种输入运动学下，还可以准确预测聚乙烯插入物表面上损伤斑块的大小和形状。该模型通过考虑应变硬化来预测多种加载情况下的植入物损伤的能力使其成为筛选新植入物设计的理想选择，因为植入物运动学在很大程度上是组件形状的函数。
