Water effects on the mechanical properties of rocks have been extensively investigated through experiments and numerical models.However,few studies have established a comprehensive link between the microscopic mechani...Water effects on the mechanical properties of rocks have been extensively investigated through experiments and numerical models.However,few studies have established a comprehensive link between the microscopic mechanisms of water-related micro-crack and the constitutive behaviors of rocks.In this work,we shall propose an extended micromechanical-based plastic damage model for understanding weakening effect induced by the presence of water between micro-crack’s surfaces on quasi-brittle rocks,based on the Mori-Tanaka homogenization and irreversible thermodynamics framework.Regarding the physical mechanism,water strengthens micro-crack propagation,which induces damage evolution during the pre-and post-stage,and weakens the elastic effective properties of rock matrix.After proposing a special calibration procedure for the determination of model parameters based on the laboratory compression tests,the proposed micromechanical-based model is verified by comparing the model predictions to the experimental results.The model effectively captures the mechanical behaviors of quasibrittle rocks subjected to the weakening effects of water.展开更多
Constitutive models play an essential role in numerical modeling and simulation of nonlinear deformation, progressive damage and failure of rock-like materials and structures. Recent advances in the quasi-brittle fiel...Constitutive models play an essential role in numerical modeling and simulation of nonlinear deformation, progressive damage and failure of rock-like materials and structures. Recent advances in the quasi-brittle field show that upscaling methods by homogenization have provided a new efficient way to derive macroscopic formulations of rocks from their microstructure information and local properties and then to model nonlinear mechanical behaviors identified at laboratory. This paper aims first at relating the mechanical phenomena on sample scale to their respective mechanisms on microscale. Main focus is put on unilateral effects due to crack’s opening/closure transition, material anisotropy induced by crack growth in some preferred directions and multiphysical coupling at microcracks. After a brief introduction to the linear homogenization method and its application to crack problems, we present some recent advances achieved in the combined homogenization/thermodynamics framework, including anisotropic unilateral damage-friction coupling, theoretical failure prediction in conjunction with deformation analyses, poromechanical coupling, analytical solutions and numerical implementation with application to typical brittle rocks.展开更多
The CT technique was first applied to observing the nasal cavity of Ikechosaurus sunailinae. The results indicate that the nasal cavity is very complex, and it was divided into two parts: the posterior-upper part and ...The CT technique was first applied to observing the nasal cavity of Ikechosaurus sunailinae. The results indicate that the nasal cavity is very complex, and it was divided into two parts: the posterior-upper part and the anterior-lower one. These control olfaction and ther-展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.42001053 and 42277147)the General Scientific Research Fund of Zhejiang Provincial Education Department(No.Y202352363)the University Natural Science Foundation of Jiangsu Province(No.23KJD130001)。
文摘Water effects on the mechanical properties of rocks have been extensively investigated through experiments and numerical models.However,few studies have established a comprehensive link between the microscopic mechanisms of water-related micro-crack and the constitutive behaviors of rocks.In this work,we shall propose an extended micromechanical-based plastic damage model for understanding weakening effect induced by the presence of water between micro-crack’s surfaces on quasi-brittle rocks,based on the Mori-Tanaka homogenization and irreversible thermodynamics framework.Regarding the physical mechanism,water strengthens micro-crack propagation,which induces damage evolution during the pre-and post-stage,and weakens the elastic effective properties of rock matrix.After proposing a special calibration procedure for the determination of model parameters based on the laboratory compression tests,the proposed micromechanical-based model is verified by comparing the model predictions to the experimental results.The model effectively captures the mechanical behaviors of quasibrittle rocks subjected to the weakening effects of water.
基金financial support from the National Natural Science Foundation of China (Grant No. 51679068)the Fundamental Research Funds for the Central Universities (Grant Nos. 2014B06914 and 2016B20214)
文摘Constitutive models play an essential role in numerical modeling and simulation of nonlinear deformation, progressive damage and failure of rock-like materials and structures. Recent advances in the quasi-brittle field show that upscaling methods by homogenization have provided a new efficient way to derive macroscopic formulations of rocks from their microstructure information and local properties and then to model nonlinear mechanical behaviors identified at laboratory. This paper aims first at relating the mechanical phenomena on sample scale to their respective mechanisms on microscale. Main focus is put on unilateral effects due to crack’s opening/closure transition, material anisotropy induced by crack growth in some preferred directions and multiphysical coupling at microcracks. After a brief introduction to the linear homogenization method and its application to crack problems, we present some recent advances achieved in the combined homogenization/thermodynamics framework, including anisotropic unilateral damage-friction coupling, theoretical failure prediction in conjunction with deformation analyses, poromechanical coupling, analytical solutions and numerical implementation with application to typical brittle rocks.
文摘The CT technique was first applied to observing the nasal cavity of Ikechosaurus sunailinae. The results indicate that the nasal cavity is very complex, and it was divided into two parts: the posterior-upper part and the anterior-lower one. These control olfaction and ther-