A strain-mediated corrosion model for bioabsorbable metallic stents
A strain-mediated corrosion model for bioabsorbable metallic stents
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DOI：
10.1016/j.actbio.2017.04.020
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发表时间：
2017-06-01
影响因子：
9.7
通讯作者：
Lally, C.
中科院分区：
文献类型：
--
作者：
Galvin, E.;O'Brien, D.;Lally, C.
本文提出了一种基于离散有限元模拟方法的应变介观唯象腐蚀模型，该方法是为使用有限元程序而开发的。根据实验数据对腐蚀模型进行了标定，并用该模型模拟了WE43镁合金支架的腐蚀行为。该模型能够预测实验观察到的塑性应变介导的质量损失分布。根据实验数据外推的非线性塑性应变模型也被发现能够很好地反映腐蚀引起的支架径向硬度随时间的降低。开发的模型将有助于指导未来的设计工作，在设备制造、部署和使用期间将塑性应变降至最低，以降低腐蚀率并延长镁设备的机械完整性。意义陈述探索应变与腐蚀损伤相互作用的腐蚀模型的必要性已被认为是当前可降解材料建模中的挑战之一(Gastaldi等人，2011年)。建立了基于塑性应变的唯象腐蚀有限元模型，并根据腐蚀实验结果对模型进行了标定。研究发现，它能够预测实验中观察到的塑性应变介导的质量损失分布，以及随着时间的推移，腐蚀导致支架径向硬度降低的情况。据作者所知，本文给出的结果是对腐蚀镁支架的塑性应变中介腐蚀模型的首次实验校准。(C)2017 Acta Materialia Inc.由Elsevier Ltd.出版。保留所有权利。
This paper presents a strain-mediated phenomenological corrosion model, based on the discrete finite element modelling method which was developed for use with the ANSYS Implicit finite element code. The corrosion model was calibrated from experimental data and used to simulate the corrosion performance of a WE43 magnesium alloy stent. The model was found to be capable of predicting the experimentally observed plastic strain-mediated mass loss profile. The non-linear plastic strain model, extrapolated from the experimental data, was also found to adequately capture the corrosion-induced reduction in the radial stiffness of the stent over time. The model developed will help direct future design efforts towards the minimisation of plastic strain during device manufacture, deployment and in-service, in order to reduce corrosion rates and prolong the mechanical integrity of magnesium devices.Statement of SignificanceThe need for corrosion models that explore the interaction of strain with corrosion damage has been recognised as one of the current challenges in degradable material modelling (Gastaldi et al., 2011). A finite element based plastic strain-mediated phenomenological corrosion model was developed in this work and was calibrated based on the results of the corrosion experiments. It was found to be capable of predicting the experimentally observed plastic strain-mediated mass loss profile and the corrosion-induced reduction in the radial stiffness of the stent over time. To the author's knowledge, the results presented here represent the first experimental calibration of a plastic strain-mediated corrosion model of a corroding magnesium stent. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.