等效参数替换法构建混凝土界面过渡区的数值模型研究

Research on the Numerical Model Construction of Concrete Interfacial Transition Zone Using Equivalent Parameter Substitution Method

混凝土界面过渡区的厚度在微米级范围,为了达到界面相超薄体在混凝土细观仿真模拟中应用的目的,对混凝土三维三相模型进行五面体和四面体网格的混合划分,以四、五面体相同的力学传递结果为依据,替换有限元模型HJC本构关系的计算参数。结果表明,混合划分等效模型与全四面体划分模型的有限元计算结果一致,混合网格建模是可行的。在不同冲击速度下进行Ansys/LS-DYNA有限元数值仿真,采用微米级厚度界面相等效参数替换方法得到的数值模拟破坏模式和应力-应变曲线结果与试验结果拟合良好。

The thickness of the concrete interfacial transition zone is in the micrometer range.In order to achieve the application of the ultra-thin interfacial phase in the mesoscopic simulation of concrete,a mixed division of tetrahedral and pentahedral meshes was carried out for the three-dimensional three-phase model of concrete.Based on the consistent mechanical transmission results of tetrahedrons and pentahedrons,the computational parameters of the HJC constitutive relation in the finite element model were replaced.The results show that the finite element calculation results of the mixed division equivalent model are consistent with those of the all-tetrahedral division model,indicating that the mixed mesh modeling is feasible.Ansys/LS-DYNA finite element numerical simulations were carried out at different impact velocities,and the numerical simulation damage modes and stress-strain curves obtained by the equivalent parameter substitution method for the interphase of micrometer-level thickness fit well with the experimental results.