A multi-physics model has been developed to investigate the effects of cellular level mechanisms on the electro-thermo-mechanical response of hydrated soft tissues with radiofrequency (RF) activation. A micromechanical model generates an equation of state (EOS) that provides the additional pressure arising from evaporation of intra- and extracellular water as well as temperature to the continuum level thermo-mechanical model. A level set method is used to capture the interfacial evolution of tissue damage with the level set evolution equation derived from the second law of thermodynamics, which is consistent with Griffith's fracture evolution criterion. The discretized equations are solved simultaneously using a Krylov subspace based iterative solver (GMRES) with block preconditioning that effectively deflates the spectrum of the system matrix, resulting in exponential convergence of the Arnoldi iterations. Example problems, including experimental validation, illustrate the computational accuracy and efficiency of the technique.

中文翻译：

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软水合组织射频激活的多物理场模型

我们开发了一种多物理模型来研究细胞水平机制对射频 (RF) 激活水合软组织电热机械响应的影响。微机械模型生成状态方程 (EOS)，为连续体水平热机械模型提供因细胞内和细胞外水蒸发而产生的额外压力以及温度。采用水平集方法，利用热力学第二定律导出的水平集演化方程来捕获组织损伤的界面演化，该方程与格里菲斯的断裂演化准则一致。使用基于 Krylov 子空间的迭代求解器 (GMRES) 与块预处理同时求解离散方程，该块预处理可有效缩小系统矩阵的频谱，从而导致 Arnoldi 迭代的指数收敛。示例问题（包括实验验证）说明了该技术的计算准确性和效率。