A phase field-based framework for electro-chemo-mechanical fracture: crack-contained electrolytes, chemical reactions and stabilisation
A phase field-based framework for electro-chemo-mechanical fracture: crack-contained electrolytes, chemical reactions and stabilisation
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DOI：
10.1016/j.cma.2023.116235
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发表时间：
2023-07
期刊：
影响因子：
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通讯作者：
T. Hageman;E. Mart'inez-Paneda
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文献类型：
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作者：
T. Hageman;E. Mart'inez-Paneda
我们提出了一个新的理论和计算框架建模电化学机械断裂。该模型结合了相场描述断裂与电解质行为，表面化学反应和应力辅助扩散的完全耦合的表征。重要的是，一个新的物理为基础的配方来描述含电解质的相场裂纹，适当捕获的电化学传输和反应动力学的裂纹开口高度的敏感性。与其他现有的方法不同，这种方法被证明是准确地捕捉离散裂缝模拟得到的结果。提出的电化学力学模型的潜力，证明了它的特殊化暴露于水电解质的金属样品的氢脆分析。有限元实现作为节点自由度的电解质电位，相关离子物种的浓度，表面覆盖，稀释物种的浓度，位移场和相场序参数。特别注意的是致力于提高稳定性和效率，从而在发展战略，以避免不良约束的自由度和集总积分计划，消除数值振荡。进行的数值实验展示了该模型的能力，以提供自由流动和裂纹包含电解质的系统的预测。所获得的结果突出了电解质的行为在驱动裂解过程中的作用，证明了现有模型的局限性。
We present a new theoretical and computational framework for modelling electro-chemo-mechanical fracture. The model combines a phase field description of fracture with a fully coupled characterisation of electrolyte behaviour, surface chemical reactions and stress-assisted diffusion. Importantly, a new physics-based formulation is presented to describe electrolyte-containing phase field cracks, appropriately capturing the sensitivity of electrochemical transport and reaction kinetics to the crack opening height. Unlike other existing methods, this approach is shown to accurately capture the results obtained with discrete fracture simulations. The potential of the electro-chemo-mechanical model presented is demonstrated by particularising it to the analysis of hydrogen embrittlement in metallic samples exposed to aqueous electrolytes. The finite element implementation takes as nodal degrees-of-freedom the electrolyte potential, the concentrations of relevant ionic species, the surface coverage, the concentration of diluted species, the displacement field and the phase field order parameter. Particular attention is devoted to improve stability and efficiency, resulting in the development of strategies for avoiding ill-constrained degrees of freedom and lumped integration schemes that eliminate numerical oscillations. The numerical experiments conducted showcase the ability of the model to deliver assumptions-free predictions for systems involving both free-flowing and crack-contained electrolytes. The results obtained highlight the role of electrolyte behaviour in driving the cracking process, evidencing the limitations of existing models.