基于多物理场模拟的石墨烯改性水泥电热力学性能分析

Analysis of Electrothermal and Mechanical Properties of Graphene-Modified Cement Based on Multiphysics Simulation

摘要: 复合电热水泥材料在智能建筑、路面融雪、结构监测等领域具有广阔应用前景，然而，现有研究多局限于定性或单尺度分析，缺乏从微观结构到宏观性能的跨尺度定量关联。本研究构建了一个微观–宏观跨尺度分析框架，基于COMSOL Multiphysics建立了石墨烯–水泥基复合材料的多尺度模型。该模型涵盖微观代表体积元(REV)及宏观试件两个层面：首先通过自编随机分布算法生成石墨烯掺杂水泥的REV微观模型，基于胡克定律焦耳，定律及傅里叶定律开发了材料等效性能参数计算方法，系统研究掺量在0.1~1.2 wt%范围内材料的性能变化；进而建立宏观试件的电–热–力学多物理场耦合模型，分析其在外部电压作用下的结构响应与性能演化规律，并进行相关实验。0.8 wt%石墨烯为最优掺量，水泥基复合材料电热–力学性能协同提升：弹性模量提高12.2%，电阻率降低63.4%，导热系数跃升128.5%，实现电热力学综合性能最优化。36 V电压下材料可实现有效且均匀的温升，同时热位移可控，兼顾了性能需求与工程安全标准，并且与实际相比误差较小。试件的多物理场模拟揭示了材料电–热–力响应与相互作用的内在机制：电场决定焦耳热源分布，热传导与边界散热耦合形成稳定的温度场，在机械约束下引发非均匀的应力应变。本研究实现了从纳米尺度结构设计到宏观性能预测的跨尺度关联，为石墨烯改性水泥基电热材料的优化设计与工程应用提供了系统的理论依据。

Abstract: Composite electrothermal cement materials hold broad application prospects in intelligent buildings, road snow melting, and structural monitoring. However, existing research is mostly limited to qualitative or single-scale analyses, lacking quantitative cross-scale correlations from microstructure to macroscopic performance. This study establishes a micro-macro cross-scale analysis framework and develops a multiscale model of graphene-cement-based composites based on COMSOL Multiphysics. The model spans two levels: a microscopic Representative Volume Element (REV) and a macroscopic specimen. First, a self-developed random distribution algorithm is employed to generate the REV microstructure model of graphene-doped cement. A method for calculating the equivalent material performance parameters is developed based on Hooke’s law, Joule’s law, and Fourier’s law, systematically investigating the performance variations of the material within the graphene content range of 0.1~1.2 wt%. Subsequently, a multiphysics coupling model for electro-thermo-mechanical analysis is established at the macroscopic specimen level to analyze its structural response and performance evolution under applied voltage, accompanied by corresponding experiments. The optimal graphene content is identified as 0.8 wt%, resulting in synergistic enhancement of the electro-thermal and mechanical properties of the cement-based composite: the elastic modulus increases by 12.2%, electrical resistivity decreases by 63.4%, and thermal conductivity rises significantly by 128.5%, achieving optimal comprehensive electro-thermo-mechanical performance. Under a 36 V voltage, the material achieves effective and uniform temperature rise while maintaining controllable thermal displacement, satisfying both performance requirements and engineering safety standards, with minimal deviation from experimental results. The multiphysics simulation of the specimen reveals the intrinsic mechanism of electro-thermo-mechanical responses and interactions: the electric field determines Joule heat distribution, heat conduction couples with boundary heat dissipation to form a stable temperature field, which induces non-uniform stress and strain under mechanical constraints. This study establishes a cross-scale correlation from nanoscale structural design to macroscopic performance prediction, providing a systematic theoretical basis for the optimized design and engineering application of graphene-modified cement-based electrothermal materials.