基于多物理场耦合的混凝土湿热变形数值模拟

Multi-physical field coupling simulation of hygro-thermal deformation of concrete

为研究混凝土湿热耦合变形,基于混凝土微观组成结构特点,根据多物理场耦合作用和多孔介质湿热传输原理,建立了混凝土湿-热-力多物理场模型.并利用COMSOL数值仿真软件和提出的混凝土湿膨胀系数,在人机交互环境下,实现湿-热-力耦合数值求解.首先以Hundt试验为算例,验证了耦合模型和求解方法的可行性,然后利用该方法对某隧道混凝土湿热耦合变形进行了模拟计算.将多物理场耦合数值模拟结果与解析-有限元结合解法计算结果和现场光纤光栅监测结果对比表明,基于多物理场耦合的混凝土湿热耦合变形数值模拟更接近监测结果,更能反映实际物理过程且具备更好的通用性.

Based on the microstructure of concrete,a hygro-thermo-mechanical model is established to investigate the hygro-thermal deformation of concrete according to the coupling effect of multi-physical field and the transfer mechanism of moisture and heat in porous medium.The COMSOL software is used to solve the hygro-thermo-mechanical coupling question in an interactive environment with the help of the presented moisture expansion coefficient of concrete.The feasibility of the model and the solution method is validated by Hundt＇s experimental results.And the hygro-thermal deformation of a lake tunnel is also numerically simulated by COMSOL.The result of COMSOL multi-physical numerical simulation,the numerical result of hybrid analytic-finite element method（A-FEM） method and the fiber Bragg grating（FBG） monitoring data are comparatively analyzed.It is revealed that the COMSOL simulation result is more close to the field test data than that of the A-FEM method.It can be concluded that the COMSOL simulation is more adequate to reveal the physical progress of concrete deformation with better feasibility.