混凝土材料损伤-自愈行为的湿化力多场耦合分析

Hygro-Chemical-Mechanical Multi-Field Coupling Analysis on Damage-Healing Behavior of Concrete

荷载与环境共同工作下的混凝土损伤-愈合力学行为具有典型的内在湿化力多场耦合特征.本文以混凝土中CaCO3沉淀自愈机制为例,建立了一种湿-化-力多场耦合分析模型.通过引入一组扩散和化学反应方程,对材料微观结构层次的物理化学过程进行数学建模.随后,基于连续损伤愈合力学理论,将自愈效应引入混凝土损伤本构关系,发展出混凝土湿化力耦合分析模型并进行模型验证.针对单轴拉伸混凝土试样进行多场耦合数值分析,考察了关键参数对愈合过程的作用规律以及自愈进程对混凝土材料力学行为的影响.本文的研究为混凝土在运行环境下的损伤-愈合行为以及性能演变提供了定量分析方法.

Damage-healing behavior of concrete under the combined action of mechanical load and environment has an inherently hygro-chemical-mechanical coupling characteristic.In this paper,taking the self-healing mechanism of CaCO3 precipitation in concrete as an example,a hygro-chemical-mechanical multi-field coupling analysis model was established.By introducing a set of diffusion equations and chemical reaction equations,the underlying physicochemical processes at the microstructure level were mathematically modeled.At the same time,based on the theory of continuous damage-healing mechanics,the self-healing effect was embedded into the constitutive equation of concrete.After model validation,the multi-field coupling method was applied to a uniaxial-tensile concrete specimen to explore the effect of key parameters on the healing process,as well as to obtain the influence of self-healing process on the macro mechanical behavior of concrete materials.The work provides a quantitative tool for analyzing the damage-healing behavior and performance evaluation of the concrete in the operational environment.