A peridynamic model for galvanic corrosion and fracture
A peridynamic model for galvanic corrosion and fracture
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DOI：
10.1016/j.electacta.2021.138968
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发表时间：
2021-09
影响因子：
6.6
通讯作者：
Jiangming Zhao;S. Jafarzadeh;M. Rahmani;Ziguang Chen;Yong-Rak Kim;F. Bobaru
中科院分区：
文献类型：
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作者：
Jiangming Zhao;S. Jafarzadeh;M. Rahmani;Ziguang Chen;Yong-Rak Kim;F. Bobaru
引入了近场动力学（PD）耦合腐蚀-断裂模型，其中局部腐蚀速率通过解决相应的静电问题来确定。由于能够考虑沿阳极表面的腐蚀速率的变化分布，该模型对于模拟电偶腐蚀特别有用。为腐蚀模型中的参数提供了一种新颖的分析校准。腐蚀模型根据电势、电流密度和腐蚀深度进行了验证，并根据文献中的 AE44（镁合金）-低碳钢和 AE44-AA6063（铝合金）电偶的实验结果进行了验证。 PD 结果还与基于 COMSOL FEM 的模型的结果进行了比较。研究发现，为了提供合理的结果，COMSOL 模型需要在电连接处对几何形状进行人为的初始“降压”，但在 PD 模型中则不需要。解决了电化学腐蚀与机械载荷引起的应变相结合的电偶腐蚀-断裂问题。
A coupled peridynamic (PD) corrosion-fracture model is introduced, in which the local corrosion rate is determined by solving the corresponding electrostatic problem. By being able to consider variable distributions of corrosion rates along the anodic surface, the model is particularly useful for simulating galvanic corrosion. A novel analytical calibration for parameters in the corrosion model is provided. The corrosion model is verified in terms of the electric potential, current density, and corrosion depth, and validated against experimental results for AE44 (Mg alloy) – mild steel and AE44 – AA6063 (Al alloy) galvanic couples taken from the literature. The PD results are also compared with those from a COMSOL FEM-based model. It is found that an artificial initial “step-down” in geometry at the galvanic joint is required for the COMSOL model in order to provide reasonable results, but it is not needed in the PD model. A coupled galvanic corrosion-fracture problem accounting for the combined electro-chemical attack and strains induced by mechanical loadings is solved.