高温下混凝土多相耦合模型数值求解

随着混凝土,特别是高性能混凝土(HPC)在工程中的推广和应用,建立其在不同自然和工程条件下的数学模型,模拟其中发生、发展的物理-化学现象与耦合过程,具有重要科学意义和经济效益.将混凝土材料模型化为非饱和多孔多相系统,基于含有多相流体的变形多孔介质的质量、动量和能量守恒方程,建立高温下混凝土热—湿—气—力学多相耦合数学模型.采用有限单元法进行空间数值离散、时域差分法进行迭代求解,为进一步实现高温下(低于孔隙水的临界温度647.3 K)混凝土的多相耦合行为模拟、分析其中的控制机理提供理论基础及可行性论证.

Numerical Solution of the Multiphase Coupling Model for Concrete at High Temperature

With the wide and increasing applications in engineering of concrete,especially the high performance concrete(HPC),it is critically important in science and economy to establish a mathematical model to simulate the coupled,multi-physical-chemical processes,which occur and develop in concrete at different working conditions.Concrete is modeled as a deforming porous medium unsaturated with multiphase pore fluids.Based on mass,momentum and energy conservation equations for the multiphase system,a coupled thermo-hygro-mechanical mathematical model for concrete is set up.Finite element method and difference time-domain method are applied into numerical discretization and iterative solution.It provides the basis and feasibility study for further numerical simulation of the multiphase coupling behaviors occurring in concrete at high temperature(below the critical point of water 647.3 K) and analysis of the mechanisms of these complex procedures.