关键词: 多晶冰, 冰川稳定性, 本构模型, 二次开发, 数值模拟

Abstract: With the gradual warming of the global climate, the possibility of large-scale sliding and collapse disasters of glaciers, large ice sheets or thicker ice layers are increasing. Research on the deformation characteristics of polycrystalline ice and establishing its constitutive model are of great significance for the disaster forecasting of polar regions. Based on the existing triaxial compression test data of artificial polycrystalline ice, it is found that the artificial polycrystalline ice has prominent characteristics of strain softening. The damage variable with equivalent plastic strain as the variable is proposed. By using the Mohr-Coulomb criterion as the initial yield function, and adopting the associated flow rule, an elastoplastic damage constitutive model that can reflect the strain softening characteristics of polycrystalline ice is established. The proposed constitutive model is verified by triaxial compression test data under different confining pressures and different temperatures, and parameter sensitivity analysis of some model parameters is carried out. The established elastoplastic damage constitutive model was written in the FLAC^3D software, and the embedded constitutive model was verified by the triaxial compression of a single unit. Then, the embedded elastoplastic damage constitutive model is used to perform triaxial compression on the cylindrical specimen. The simulation results are analyzed in detail. The results provide a theoretical and numerical basis for the stability analysis of glaciers and the multi field coupling study of glaciers.

Key words: polycrystalline ice, glacier stability, constitutive model, secondary development, numerical simulation