Dataset supporting the publication “Importance of dynamics in the finite element prediction of plastic damage of polyethylene acetabular liners under edge loading conditions”

This dataset contains the full set of output values from a modelling study, summarised as follows. After hip replacement, in cases where there is instability at the joint, contact between the femoral head and the acetabular liner can move from the bearing surface to the liner rim, generating edge loading conditions. This has been linked to polyethylene liner fracture and led to the development of a regulatory testing standard (ISO 14242:4) to replicate these conditions. Performing computational modelling alongside simulator testing can provide insight into the complex damage mechanisms present in hard-on-soft bearings under edge loading. The aim of this work was to evaluate the need for inertia and elastoplastic material properties to predict kinematics (likelihood of edge loading) and plastic strain accumulation (as a damage indicator). While a static, rigid model was sufficient to predict kinematics for experimental test planning, the inclusion of inertia, alongside elastoplastic material, was required for prediction of plastic strain behaviour. The delay in device realignment during heel strike, caused by inertia, substantially increased the force experienced during rim loading (e.g. 600 N static rigid, ~1800 N dynamic elastoplastic, in one case). The accumulation of plastic strain is influenced by factors including cup orientation, swing phase force balance, the moving mass, and the design of the device itself. Evaluation of future liner designs could employ dynamic elastoplastic models to investigate the effect of design feature changes on bearing resilience under edge loading.

本数据集包含某建模研究的全部输出数值，概述如下。全髋关节置换术后，当关节出现不稳时，股骨头（femoral head）与髋臼内衬（acetabular liner）的接触位置可从承载面转移至内衬边缘，从而产生边缘加载（edge loading）工况。该情况与聚乙烯（polyethylene）内衬断裂相关，并推动了监管测试标准ISO 14242:4的制定，以复现此类工况。结合计算建模（computational modelling）与模拟器测试（simulator testing），可深入理解边缘加载工况下硬对软轴承（hard-on-soft bearings）所涉及的复杂损伤机制。本研究的目的为评估：在预测运动学（kinematics，即边缘加载发生概率）与塑性应变累积（plastic strain accumulation，作为损伤指标（damage indicator））时，是否需要引入惯性与弹塑性材料（elastoplastic material）属性。尽管静态刚性模型（static rigid model）足以满足实验测试规划所需的运动学预测需求，但要预测塑性应变行为，则需同时引入惯性与弹塑性材料属性。惯性导致的足跟触地（heel strike）阶段假体复位延迟，显著提升了边缘加载工况下所承受的载荷（例如某案例中，静态刚性模型下为600牛，动态弹塑性模型下约为1800牛）。塑性应变累积受多种因素影响，包括髋臼杯（acetabular cup）取向、步态摆动相（swing phase）的力平衡、运动质量以及假体自身的设计。未来可通过动态弹塑性模型评估新型内衬设计，以研究边缘加载工况下设计特征变更对承载韧性（bearing resilience）的影响。