The topological attributes of fracture networks in limestone,subject to intense hydrodynamics and intricate geological discontinuities,substantially influence the mechanical and hydraulic characteristics of the rock m...The topological attributes of fracture networks in limestone,subject to intense hydrodynamics and intricate geological discontinuities,substantially influence the mechanical and hydraulic characteristics of the rock mass.The dynamical evolution of fracture networks under stress is crucial for unveiling the interaction patterns among fractures.However,existing models are undirected graphs focused on stationary topology,which need optimization to depict fractures'dynamic development and rupture process.To compensate for the time and destruction terms,we propose the damage network model,which defines the physical interpretation of fractures through the ternary motif.We focus primarily on the evolution of node types,topological attributes,and motifs of the fracture network in limestone under uniaxial stress.Observations expose the varying behavior of the nodes'self-dynamics and neighbors'adjacent dynamics in the fracture network.This approach elucidates the impact of micro-crack behaviors on large brittle shear fractures from a topological perspective and further subdivides the progressive failure stage into four distinct phases(isolated crack growth phase,crack splay phase,damage coalescence phase,and mechanical failure phase)based on the significance profile of the motif.Regression analysis reveals a positive linear and negative power correlation between fracture network density and branch number to the rock damage resistance,respectively.The damage network model introduces a novel methodology for depicting the interaction of two-dimensional(2D)projected fractures,considering the dynamic spatiotemporal development characteristics and fracture geometric variation.It helps dynamically characterize properties such as connectivity,permeability,and damage factors while comprehensively assessing damage in rock mass fracture networks.展开更多
The microstructure property relationships have been studied in terms of glass transition behavior,phase morphology,and fracture toughness on thermoplastic polyetherketone with a phenolphthalein side group (PAEK) tough...The microstructure property relationships have been studied in terms of glass transition behavior,phase morphology,and fracture toughness on thermoplastic polyetherketone with a phenolphthalein side group (PAEK) toughened bismaleimdes (BMI) resins,and in terms of interlaminar morphology and compression after impact (CAI) on the graphite fiber (T700SC),the rein-forced BMI matrix composites that are toughened with a so-called ex-situ concept,respectively. The characteristic morphology spectrum has been found ...展开更多
对铈铁掺杂铌酸锂(Ce:Fe:Li Nb O_3)晶体进行氧化、还原处理。通过红外光谱、紫外可见吸收光谱测试了晶体样品的组成和缺陷结构。采用透射光斑畸变法测试了晶体样品的抗光损伤能力,结果表明:生长态晶体比还原态晶体的抗光致散射能力基...对铈铁掺杂铌酸锂(Ce:Fe:Li Nb O_3)晶体进行氧化、还原处理。通过红外光谱、紫外可见吸收光谱测试了晶体样品的组成和缺陷结构。采用透射光斑畸变法测试了晶体样品的抗光损伤能力,结果表明:生长态晶体比还原态晶体的抗光致散射能力基本上高一个数量级,氧化态的晶体要比还原态的晶体高两个数量级。采用二波耦合实验测试了晶体样品的光折变性能,结果表明:从氧化到生长再到还原态,衍射效率逐渐降低,响应时间缩短,光折变灵敏度增加,动态范围逐渐降低。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52090081)the State Key Laboratory of Hydroscience and Engineering(Grant No.2022-KY-02).
文摘The topological attributes of fracture networks in limestone,subject to intense hydrodynamics and intricate geological discontinuities,substantially influence the mechanical and hydraulic characteristics of the rock mass.The dynamical evolution of fracture networks under stress is crucial for unveiling the interaction patterns among fractures.However,existing models are undirected graphs focused on stationary topology,which need optimization to depict fractures'dynamic development and rupture process.To compensate for the time and destruction terms,we propose the damage network model,which defines the physical interpretation of fractures through the ternary motif.We focus primarily on the evolution of node types,topological attributes,and motifs of the fracture network in limestone under uniaxial stress.Observations expose the varying behavior of the nodes'self-dynamics and neighbors'adjacent dynamics in the fracture network.This approach elucidates the impact of micro-crack behaviors on large brittle shear fractures from a topological perspective and further subdivides the progressive failure stage into four distinct phases(isolated crack growth phase,crack splay phase,damage coalescence phase,and mechanical failure phase)based on the significance profile of the motif.Regression analysis reveals a positive linear and negative power correlation between fracture network density and branch number to the rock damage resistance,respectively.The damage network model introduces a novel methodology for depicting the interaction of two-dimensional(2D)projected fractures,considering the dynamic spatiotemporal development characteristics and fracture geometric variation.It helps dynamically characterize properties such as connectivity,permeability,and damage factors while comprehensively assessing damage in rock mass fracture networks.
基金National Basic Research Programs of China (2003CB615604973)
文摘The microstructure property relationships have been studied in terms of glass transition behavior,phase morphology,and fracture toughness on thermoplastic polyetherketone with a phenolphthalein side group (PAEK) toughened bismaleimdes (BMI) resins,and in terms of interlaminar morphology and compression after impact (CAI) on the graphite fiber (T700SC),the rein-forced BMI matrix composites that are toughened with a so-called ex-situ concept,respectively. The characteristic morphology spectrum has been found ...
文摘对铈铁掺杂铌酸锂(Ce:Fe:Li Nb O_3)晶体进行氧化、还原处理。通过红外光谱、紫外可见吸收光谱测试了晶体样品的组成和缺陷结构。采用透射光斑畸变法测试了晶体样品的抗光损伤能力,结果表明:生长态晶体比还原态晶体的抗光致散射能力基本上高一个数量级,氧化态的晶体要比还原态的晶体高两个数量级。采用二波耦合实验测试了晶体样品的光折变性能,结果表明:从氧化到生长再到还原态,衍射效率逐渐降低,响应时间缩短,光折变灵敏度增加,动态范围逐渐降低。
