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Darboux Transformation and Explicit Solutions for Discretized Modified Korteweg-de Vries Lattice Equation 认领 引用 被引量：8
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作者 闻小永 高以天 《Communications in Theoretical Physics》 SCIE CAS 2010年第5期825-830,共6页
The modified Korteweg-de Vries （mKdV） typed equations can be used to describe certain nonlinear phenomena in fluids, plasmas, and optics. In this paper, the discretized mKdV lattice equation is investigated. With th... The modified Korteweg-de Vries （mKdV） typed equations can be used to describe certain nonlinear phenomena in fluids, plasmas, and optics. In this paper, the discretized mKdV lattice equation is investigated. With the aid of symbolic computation, the discrete matrix spectral problem for that system is constructed. Darboux transformation for that system is established based on the resulting spectral problem. Explicit solutions are derived via the Darboux transformation. Structures of those solutions are shown graphically, which might be helpful to understand some physical processes in fluids, plasmas, and optics. 展开更多
关键词 Darboux transformation discretized modified Korteweg-de Vries lattice equation explicit solutions symbolic computation
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Dynamic Analysis of the Seafloor Pilot Miner Based on Single-Body Vehicle Model and Discretized Track-Terrain Interaction Model 认领 引用 被引量：6
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作者 戴瑜 刘少军 李力 《China Ocean Engineering》 SCIE EI 2010年第1期145-160,共16页
In order to achieve the complex dynamic analysis of the self-propelled seafloor pilot miner moving on the seafloor of extremely cohesive soft soil and further to make it possible to integrate the miner system with som... In order to achieve the complex dynamic analysis of the self-propelled seafloor pilot miner moving on the seafloor of extremely cohesive soft soil and further to make it possible to integrate the miner system with some subsystems to form the complete integrated deep ocean mining pilot system and perform dynamic analysis, a new method for the dynamic modeling and analysis of the miner is proposed and developed in this paper, resulting in a simplified 3D single-body vehicle model with three translational and three rotational degrees of freedom, while the track-terrain interaction model is built by partitioning the track-terrain interface into discrete elements with parameterized force dements built on the theory of terramechanics acting on each discrete dement. To evaluate and verify the correctness and effectiveness of this new modeling and analysis method, typical comparative studies with regard to computational efficiency and solution accuracy are carried out between the traditional modeling method of building the tracked vehicle as a multi-body model and the new modeling method. In full consideration of the particMar structure design of the pilot miner, the special characteristics of the seafioor soil and the hydrodynamic force of near-seafloor currnt, the dynamic simulation analysis of the miner is performed and discussed, which can provide useful guidance and reference for the practical miner system in design and operation. This new method can not only realize the rapid dynamic simulation analysis of the miner but also make possible the integration and rapid dynamic analysis of the complete integrated deep ocean mining pilot system in further researches. 展开更多
关键词 deep-ocean mining system self-propelled seafloor pilot miner single-body model multi-body model discretized track-terrain interaction model dynamic analysis
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Robust Stability of Neutral Systems:A Discretized Lyapunov Functional Method 认领 引用
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作者 李旭光 朱新坚 曹广益 《Journal of Shanghai Jiaotong university(Science)》 EI 2009年第3期279-285,共7页
This paper focuses on the robust stability for time-delay systems of neutral type. A new complete Lyapunov-Krasovskii function (LKF) is developed. Based on this function and discretization, stability conditions in ter... This paper focuses on the robust stability for time-delay systems of neutral type. A new complete Lyapunov-Krasovskii function (LKF) is developed. Based on this function and discretization, stability conditions in terms of linear matrix inequalities are obtained. A class of time-varying uncertainty of system matrices can be studied by the method. 展开更多
关键词 stability time-delay systems discretized Lyapunov functional method
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Modeling rock fragmentation by coupling Voronoi diagram and discretized virtual internal bond 认领 引用
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作者 Sai Liu Zhennan Zhang 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2020年第5期321-326,共6页
The rock fragmentation involves the inter-block and the intra-block fracture.A simulation method for rock fragmentation is developed by coupling Voronoi diagram(VD)and discretized virtual internal bond(DVIB).The DVIB ... The rock fragmentation involves the inter-block and the intra-block fracture.A simulation method for rock fragmentation is developed by coupling Voronoi diagram(VD)and discretized virtual internal bond(DVIB).The DVIB is a lattice model that consists of bonds.The VD is used to generate the potential block structure in the DVIB mesh.Each potential block may contain any number of bond cells.To characterize the inter-block fracture,a hyperelastic bond potential is employed for the bond cells that are cut by the VD edges.While to characterize the intra-block fracture,an elastobrittle bond potential is adopted for the bonds in a block.By this method,both the inter-block and intra-block fracture can be well simulated.The simulation results suggest that this method is a simple and efficient approach to rock fragmentation simulation with block smash. 展开更多
关键词 Rock fragmentation Block smash Voronoi diagram Discretized virtual internal bond Fracture
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THE ACTIVATION METHOD FOR DISCRETIZED CONSERVATIVE NONLINEAR STABILITY PROBLEMS WITH MULTIPLE PARAMETER AND STATE VARIABLES 认领 引用
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作者 邓长根 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1993年第10期919-929,共11页
For nonlinear stability problems of discretized conservative systems with multiple parameter variables and multiple state variables, the activation method is put forward, by which activated potential functions and act... For nonlinear stability problems of discretized conservative systems with multiple parameter variables and multiple state variables, the activation method is put forward, by which activated potential functions and activated equilibrium equations are derived. The activation method is the improvement and enhancement of Liapunov-Schmidt method in elastic stability theory. It is more generalized and more normalized than conventional perturbation methods. The activated potential functions may be transformed into normalized catastrophe potential functions. The activated equilibrium equations may be treated as bifurcation equations. The researches in this paper will motivate the combination of elastic stability theory with catastrophe theory and bifurcation theory 展开更多
关键词 multiple parameter variables multiple state variables discretized,conservative nonlinear stability activation method asymptotic analyses
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A Bootstrapping Approach for Software Reliability Measurement Based on a Discretized NHPP Model 认领 引用
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作者 Shinji Inoue Shigeru Yamada 《Journal of Software Engineering and Applications》 2013年第4期1-7,共7页
Discrete software reliability measurement has a proper characteristic for describing a software reliability growth process which depends on a unit of the software fault-detection period, such as the number of test run... Discrete software reliability measurement has a proper characteristic for describing a software reliability growth process which depends on a unit of the software fault-detection period, such as the number of test runs, the number of executed test cases. This paper discusses discrete software reliability measurement based on a discretized nonhomogeneous Poisson process (NHPP) model. Especially, we use a bootstrapping method in our discrete software reliability measurement for discussing the statistical inference on parameters and software reliability assessment measures of our model. Finally we show numerical examples of interval estimations based on our bootstrapping method for the several software reliability assessment measures by using actual data. 展开更多
关键词 Software Reliability Measurement Discretized NHPP Model Nonparametric Bootstrapping Method Regression Analysis Bootstrap Confidence Intervals
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A multithreaded parallel upwind sweep algorithm for the SN transport equations discretized with discontinuous finite elements 认领 引用 被引量：1
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作者 Zhi‑Wei Zong Mao‑Song Cheng +1 位作者 Ying‑Chi Yu Zhi‑Min Dai 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第12期229-241,共13页
The complex structure and strong heterogeneity of advanced nuclear reactor systems pose challenges for high-fidelity neutron-shielding calculations. Unstructured meshes exhibit strong geometric adaptability and can ov... The complex structure and strong heterogeneity of advanced nuclear reactor systems pose challenges for high-fidelity neutron-shielding calculations. Unstructured meshes exhibit strong geometric adaptability and can overcome the deficiencies of conventionally structured meshes in complex geometry modeling. A multithreaded parallel upwind sweep algorithm for SN transport was proposed to achieve a more accurate geometric description and improve the computational efficiency. The spatial variables were discretized using the standard discontinuous Galerkin finite-element method. The angular flux transmission between neighboring meshes was handled using an upwind scheme. In addition, a combination of a mesh transport sweep and angular iterations was realized using a multithreaded parallel technique. The algorithm was implemented in the 2D/3D SN transport code ThorSNIPE, and numerical evaluations were conducted using three typical benchmark problems:IAEA, Kobayashi-3i, and VENUS-3. These numerical results indicate that the multithreaded parallel upwind sweep algorithm can achieve high computational efficiency. ThorSNIPE, with a multithreaded parallel upwind sweep algorithm, has good reliability, stability, and high efficiency, making it suitable for complex shielding calculations. 展开更多
关键词 Shielding calculation Discrete ordinates method Discontinuous Galerkin finite element method Unstructured meshes
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New Explicit Rational Solitary Wave Solutions for Discretized mKdV Lattice Equation 认领 引用 被引量：3
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作者 YU Ya-Xuan WANG Qi ZHANG Hong-Qing 《Communications in Theoretical Physics》 SCIE CAS 2005年第6X期1011-1014,共4页
In this letter, we study discretized mKdV lattice equation by using a new generalized ansatz. As a result,many explicit rational exact solutions, including some new solitary wave solutions, are obtained by symbolic co... In this letter, we study discretized mKdV lattice equation by using a new generalized ansatz. As a result,many explicit rational exact solutions, including some new solitary wave solutions, are obtained by symbolic computation code Maple. 展开更多
关键词 differential-difference equations discretized mKdV lattice equation solitary wave solution rational expand method
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An Improved Method to an Impulsive and Delayed Discretized Model 认领 引用
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作者 Yujing Liu Lijun Zhang Shujing Gao 《Applied Mathematics》 2016年第1期108-123,共16页
In this paper, a discretized SIR model with pulse vaccination and time delay is proposed. We introduce two thresholds R* and R*, and further prove that the disease-free periodic solution is globally attractive if R* i... In this paper, a discretized SIR model with pulse vaccination and time delay is proposed. We introduce two thresholds R* and R*, and further prove that the disease-free periodic solution is globally attractive if R* is less than unit and the disease can invade if R* is larger than unit. The numerical simulations not only illustrate the validity of our main results, but also exhibit bifurcation phenomenon. Our result shows that decreasing infection rate can put off the disease outbreak and reduce the number of infected individuals. 展开更多
关键词 Discrete Epidemic Model Time Delay Pulse Vaccination Extinction
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Thermal damage and permeability evolution in granite subjected to rapid heating and cooling : Experimental and numerical insights 认领 引用 被引量：1
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作者 CHEN Yong-jun YIN Tu-bing +4 位作者 RANJITH P G LI Xi-bing YIN Zhi-qiang SUN Dao-yuan LI Hong-ru 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第3期1203-1241,共39页
As clean energy technologies advance,the engineering challenges caused by rapid thermal fluctuations are expected to become more complex.This study investigates the damage behavior of granite subjected to rapid heatin... As clean energy technologies advance,the engineering challenges caused by rapid thermal fluctuations are expected to become more complex.This study investigates the damage behavior of granite subjected to rapid heating and cooling,focusing on the underlying damage evolution processes.A range of experimental and computational methods,including nuclear magnetic resonance(NMR),synchronous thermal analyzer(STA),and discrete element method(DEM),were used.The results show that as temperature increases,material density,P-wave velocity,and dynamic elastic modulus decline exponentially,while the damage index and linear thermal expansion coefficient increase.Thermal damage primarily results from dehydration,thermal expansion,decarbonation,plasticization,phase changes,cracking,and decomposition.Thermal shock decreases the contribution of micropores to total porosity,while macropores grow above 200℃.The study also improves the Schlumberger-Doll-Research(SDR)and Timur-Coates models,enhancing the accuracy of permeability predictions under different cooling conditions.High temperatures slightly reduce the fractal dimension of the pore structure,which negatively correlates with permeability.As temperature rises,pore coalescence and crack propagation increase,significantly altering permeability.DEM simulations show that cracks are mainly influenced by tensile stresses and thermal expansion and contraction stresses.Higher heating temperatures cause more extensive cracks,while crack contributions decrease during cooling at 600℃.Thermal damage creates additional energy release paths,increasing local thermal resistance and hindering heat transfer.Finally,thermal cycling results in a more directional crack distribution and a notable decrease in contact angles at 600℃,indicating microstructure rearrangement. 展开更多
关键词 granite rapid heating and cooling nuclear magnetic resonance damage evolution pore characteristics discrete element method
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Influence of bedding and prefabricated fissure angles on cement-bonded sand 3 D-printed Brazilian discs:Experimental investigations and PFC modelling 认领 引用 被引量：1
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作者 SUN Yi-qing XIA Shi-fa +3 位作者 HUANG Wei YANG Wei-cai GAN Lei ZHANG Wen-bing 《Journal of Central South University》 SCIE EI CAS CSCD 2026年第3期1371-1386,共16页
Bedding structures significantly influence rock mass deformation and failure,challenging engineering stability.This study aimed to investigate the fracture mechanisms of layered rock masses by examining the effects of... Bedding structures significantly influence rock mass deformation and failure,challenging engineering stability.This study aimed to investigate the fracture mechanisms of layered rock masses by examining the effects of bedding and prefabricated fissure inclination angles on the mechanical behavior of layered Brazilian disc specimens.Layered rock-like Brazilian disc specimens were prepared by combining sand 3 D printing technology with cement slurry as a bonding agent,enabling precise control of bedding features.Uniaxial compression tests,with a loading rate of 0.3 mm/min,coupled with digital image correlation(DIC)technology,were conducted to capture load−displacement curves and crack propagation processes,with two schemes designed to explore varying prefabricated fissure inclination angles(α)and bedding inclination angles(β).Additionally,the discrete element method(DEM)using particle flow code(PFC)with parallel bond(PB)and smooth-joint(SJ)models was employed for numerical simulation,with mesoscopic parameters calibrated against experimental data.The results showed that both α and β significantly affected crack propagation and failure modes:Increasing α led to a gradual increase in peak strength,with cracks initiating from fissure tips and propagating toward loading points;Increasing β caused the failure mode to transition from vertical splitting to bedding-controlled fracture,with peak strength first decreasing,and then increasing.PFC simulations effectively reproduced experimental load−displacement curves and crack morphologies,confirming numerical reliability.This study demonstrates that sand 3 D printing with cement bonding is viable for fabricating layered rock-like specimens,and the combined experimental and numerical results provide insights into layered rock fracture mechanisms,offering references for understanding bedding and prefabricated fissure influences on rock mechanical behavior. 展开更多
关键词 bedded rock masses sand 3 D printing cement slurry bonding Brazilian disc test PFC discrete element simulation
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Coupled FEM-DEM modeling of permeability evolution in rough fractured shale during shearing under varying confining pressures 认领 引用 被引量：2
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作者 Bin Li Qi Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第3期1736-1754,共19页
The dynamic evolution of fracture permeability presents a critical scientific challenge in rock masses.Understanding the mechanisms of rock mass permeability evolution is vital for engineering project design and opera... The dynamic evolution of fracture permeability presents a critical scientific challenge in rock masses.Understanding the mechanisms of rock mass permeability evolution is vital for engineering project design and operations.By integrating the discrete element method(DEM)with the finite element method(FEM),a numerical simulation framework for shear seepage in rough fractured shale has been developed to investigate the dynamic mechanisms of permeability evolution under varying confining pressures and during the shearing process.Numerical simulations were conducted on rough fractured samples under effective confining pressures ranging from 5 MPa to 20 MPa to monitor the aperture and permeability evolution of the fracture.The results of the numerical simulation are consistent with the experimental observations,indicating that both the shearing process and confining pressure significantly influence permeability.Moreover,the magnitude of the confining pressure is a crucial factor influencing the trend in permeability changes.Under a confining pressure of 5 MPa,fracture permeability initially increases significantly but decreases post-shearing.In contrast,a continuous decrease in fracture permeability is observed when the confining pressure exceeds 10 MPa.The results of the shear numerical simulation indicate that the confining pressure restricts fracture dilation during shearing,promotes the generation of rock debris,and decreases both the permeability and transmissivity of the fracture.The wear results obtained from numerical simulations are consistent with the experimental patterns and correlate with the joint roughness coefficient(JRC).This study proposed an effective numerical simulation method to reveal the evolution mechanism of fracture flow capacity,taking into account the wear of the fracture surface in shear simulations and the initial stress state of the rock in seepage simulations.This research explains the permeability evolution mechanism of fractured shale from a microscopic perspective,and the proposed numerical simulation method for shear seepage provides a powerful means to uncover the dynamic evolution mechanisms governing fracture permeability. 展开更多
关键词 Discrete element method(DEM) Finite element method(FEM) Fracture Permeability Shear stress Joint roughness coefficient(JRC) Dynamic evolution
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Bifurcation behaviors of an Euler discretized inertial delayed neuron model 认领 引用 被引量：2
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作者 HE Xing LI ChuanDong +1 位作者 HUANG TingWen YU JunZhi 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第3期418-427,共10页
This paper presents an Euler discretized inertial delayed neuron model, and its bifurcation dynamical behaviors are discussed. By using the associated characteristic model, center manifold theorem and the normal form ... This paper presents an Euler discretized inertial delayed neuron model, and its bifurcation dynamical behaviors are discussed. By using the associated characteristic model, center manifold theorem and the normal form method, it is shown that the model not only undergoes codimension one(flip, Neimark-Sacker) bifurcation, but also undergoes cusp and resonance bifurcation(1:1 and 1:2) of codimension two. Further, it is found that the parity of delay has some effect on bifurcation behaviors. Finally, some numerical simulations are given to support the analytic results and explore complex dynamics, such as periodic orbits near homoclinic orbits, quasiperiodic orbits, and chaotic orbits. 展开更多
关键词 resonance bifurcation Euler discretized inertial delayed neural network
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Elastic scattering and total reaction cross sections of6Li examined via a microscopic continuum discretized coupled-channels model 认领 引用 被引量：1
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作者 陈文棣 庞丹阳 +3 位作者 郭海瑞 叶涛 孙伟力 应阳君 《Chinese Physics C》 SCIE CAS CSCD 2024年第1期71-81,共11页
We present a systematic study of 6Li elastic scattering and total reaction cross sections at incident energies around the Coulomb barrier within the continuum discretized coupled-channels(CDCC)framework,where 6Li is t... We present a systematic study of 6Li elastic scattering and total reaction cross sections at incident energies around the Coulomb barrier within the continuum discretized coupled-channels(CDCC)framework,where 6Li is treated in anα+d two-body model.Collisions with 27Al,64Zn,138Ba,and 208Pa are analyzed.The microscopic optical potentials(MOP)based on Skyrme nucleon-nucleon interaction forαand d are adopted in CDCC calculations and satisfactory agreement with the experimental data is obtained without any adjustment on MOPs.For comparison,αand d global phenomenological optical potentials(GOP)are also used in CDCC analysis and a reduction of no less than 50%on the surface imaginary part of deuteron GOP is required for describing the data.In all cases,the 6Li breakup effect is significant and provides repulsive correction to the folding model potential.The reduction on the surface imaginary part of GOP of deuteron reveals a strong suppression of the reaction probability of deuteron as a component of 6Li when compared with that of a free deuteron.Further investigation is performed by considering the d breakup process equivalently within the dynamic polarization potential approach,and the results show that d behaves in a manner similar to a tightly bound nucleus in 6Li induced reactions. 展开更多
关键词 continuum discretized coupled channels method microscopic optical potential 6Li induced reaction elastic scattering total reaction cross section
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Fixed points as regulatory hubs in discrete memristive neural networks:An analysis of the FitzHugh–Nagumo model 认领 引用
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作者 Shaobo He Jiawei Xiao +1 位作者 Qilai Chen Huihai Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2026年第6期207-226,共20页
This study investigates the dynamics of discrete memristive FitzHugh–Nagumo(FHN)neural networks.We introduce a discrete memristor with hyperbolic tangent nonlinearity and incorporate it into neuron models ranging fro... This study investigates the dynamics of discrete memristive FitzHugh–Nagumo(FHN)neural networks.We introduce a discrete memristor with hyperbolic tangent nonlinearity and incorporate it into neuron models ranging from single neurons and coupled pairs to complex networks with ring and small-world topologies.Stability and bifurcation analyses reveal transitions from periodic to chaotic dynamics.A key contribution is the identification of a constant fixed point that remains invariant across periodic,weakly chaotic,and chaotic regimes.Linear stability analysis of this fixed point provides a fundamental basis for understanding the system's dynamical evolution.The fixed point theory explains how memristive coupling induces diverse synchronization patterns,including stable phase-locking and synchronization–desynchronization transitions,and further accounts for the emergence of chimera states in ring networks as well as their alteration in smallworld networks owing to long-range connections.Field-programmable gate array(FPGA)implementation successfully validates the mathematical models,confirming the feasibility of hardware realization.Overall,this work establishes a theoretical framework linking fixed point properties with firing mechanisms and synchronization dynamics in discrete memristive FHN neural networks,providing insights into potential applications in neuromorphic computing. 展开更多
关键词 discrete memristor discrete neuron complex network chimera state FPGA implementation
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Effects of internal parts on burden distribution and segregation in bell-less top blast furnace 认领 引用
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作者 Wang Zeng Ye-Han Fang +6 位作者 Zuo-Bang Chen De-Sheng Zou Guang-Liang Wang Yun-Peng Si Heng Zhou Tian-Xiang Zhang Ming-Yin Kou 《Journal of Iron and Steel Research International》 SCIE EI CSCD 2026年第4期241-255,共15页
As the key equipment connecting the feeding belt to the top of blast furnace,the structure of the hoppers directly affects the burden distribution in blast furnace throat.Therefore,it is of great significance to explo... As the key equipment connecting the feeding belt to the top of blast furnace,the structure of the hoppers directly affects the burden distribution in blast furnace throat.Therefore,it is of great significance to explore the suitable structure of the hoppers to optimize the burden and gas distribution of the blast furnace and improve the gas utilization rate.A three-dimensional model of a 1:1 bell-less top blast furnace with serial-type hoppers was established based on the discrete element method,which simulates the entire movement process of the burden from the belt to each hopper and then to the throat.The effects of internal components,such as the distributor,guiding cone,and buffer platform,on particle size segregation in the upper hopper,the weighing hopper,and the throat of the blast furnace were investigated.The results indicate that removing the distributor can reduce the burden segregation during the discharge from the weighing hopper.The guiding cone significantly influences the radial particle size distribution within the weighing hopper and its discharge.Eliminating the buffer platform promotes a more uniform burden distribution both in the weighing hopper and the throat of the blast furnace.Among the conditions investigated,removing the distributor and the buffer platform yields the best distribution,with the segregation index improved by 92%compared to the base model,which is recommended for practical operations. 展开更多
关键词 Blast furnace Burden distribution Segregation Internal part Discrete element method
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Mechanical behavior,failure characteristics and energy evolution of layered rock subjected to uniaxial loading 认领 引用
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作者 SHUANG Haiqing LI Lei +3 位作者 XIN Jie ZHOU Bin LIN Haifei MENG Weitao 《Journal of Mountain Science》 SCIE CSCD 2026年第6期2891-2909,共19页
The stability of overlying rock strata is jointly controlled by the advancement rate of coal mining face and rock properties.However,the crossscale mechanical behavior and energy evolution mechanism of two-layered roc... The stability of overlying rock strata is jointly controlled by the advancement rate of coal mining face and rock properties.However,the crossscale mechanical behavior and energy evolution mechanism of two-layered rock under different loading rates remain unclear,and the mesoscopic fracture characteristics and crack evolution law of three-layered rock are yet to be fully elucidated.To address these gaps,uniaxial compression tests were conducted on three types of two-layered rock(siltstone-fine sandstone,siltstone-sandy mudstone,fine sandstone-sandy mudstone) under five loading rates(0.05,0.08,0.10,0.15,0.20 mm/min).Acoustic emission and digital image correlation were coupled with the energy conservation principle to systematically investigate the mechanical properties,failure modes and energy conversion characteristics of the two-layered rock.Furthermore,based on the calibrated meso-parameters of two-layered rock,particle flow code numerical simulations were performed to explore the meso-mechanical properties,crack evolution and failure modes of three-layered rock(siltstone,fine sandstone,sandy mudstone) under typical loading rates(0.05 and 0.20 mm/min).The results showed that the mechanical evolution of twolayered rock could be divided into four typical stages,with synchronized responses from AE and DIC,i.e.,compaction stage(Stage Ⅰ-characterized by loading contact and pore closure),linear elastic stage(Stage Ⅱ-marked by discrete microcrack initiation and elastic energy storage),yield stage(Stage Ⅲ-dominated by extensive crack initiation,propagation,coalescence,partial rock spalling,and dissipative energy release),and residual stage(Stage Ⅳ-governed by post-failure joint surface friction).Specifically,the siltstone-fine sandstone exhibited a particular dual-peak phenomenon.Regarding energy evolution,elastic deformation dominated before reaching peak strength,manifesting as elastic strain energy storage.Post-peak,the rock component with lower compressive strength rapidly degraded,transferring energy to the adjacent component and inducing crack propagation,coalescence,and instability.The micro-crack evolution exhibited four stages,i.e.,initialization,slow propagation,rapid propagation,and stabilization,corresponding to the mechanical behavior of the threelayered rock.Moreover,sandy mudstone was used as an intermediate layer(FSM/MSF),the number of cracks increased by 40%-75%.This study provides a theoretical basis for the stability control of overlying rock strata in mining engineering. 展开更多
关键词 Layered rock Mechanical behavior Crack characteristic Energy evolution Discrete element method
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Effects of reflection distance on Richtmyer-Meshkov instability in the reshock process:a discrete Boltzmann study 认领 引用
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作者 Huilin Lai Chuandong Lin +4 位作者 Demei Li Tao Yang Yanbiao Gan Lingyan Lian Aiguo Xu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第4期464-482,共19页
The Richtmyer-Meshkov(RM)instability occurs when a perturbed interface between two fluids undergoes impulsive acceleration due to a shock wave.In this paper,a numerical investigation of the RM instability during the r... The Richtmyer-Meshkov(RM)instability occurs when a perturbed interface between two fluids undergoes impulsive acceleration due to a shock wave.In this paper,a numerical investigation of the RM instability during the reshock process is conducted using the two-component discrete Boltzmann method.The influence of reflection distance on the RM instability,including both hydrodynamic and thermodynamic non-equilibrium effects,is explored in detail.The interaction time between the reflected shock wave and the material interface varies with different reflection distances.Larger reflection distances lead to a longer evolution time of the material interface before reshock,resulting in more complex effects on the interface deformation,the mixing extent of the fluid system,and non-equilibrium behaviors after reshock.Additionally,while the reflection distance has a minimal impact on mixing entropy before the secondary impact,a significant difference emerges after the secondary impact.This suggests that the secondary impact enhances the evolution of the RM instability.Furthermore,non-equilibrium behaviors or quantities exhibit complex dynamics due to the influence of the transmitted shock wave,transverse waves,rarefaction waves,material interfaces,and dissipation/diffusion processes. 展开更多
关键词 Richtmyer-Meshkov instability Discrete Boltzmann method Non-equilibrium effects Compressible flows Reflection distance
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Crushing evolution in pebble bed based on a novel method:a crushable DEM study 认领 引用
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作者 Jian Wang Ming‑Zhun Lei +4 位作者 Ming‑Zong Liu Qi‑Gang Wu Zi‑Cong Cai Kai‑Song Wang Hai‑Shun Deng 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第1期212-224,共13页
In this paper,a novel method for investigating the particle-crushing behavior of breeding particles in a fusion blanket is proposed.The fractal theory and Weibull distribution are combined to establish a theoretical m... In this paper,a novel method for investigating the particle-crushing behavior of breeding particles in a fusion blanket is proposed.The fractal theory and Weibull distribution are combined to establish a theoretical model,and its validity was verified using a simple impact test.A crushable discrete element method(DEM)framework is built based on the previously established theoretical model.The tensile strength,which considers the fractal theory,size effect,and Weibull variation,was assigned to each generated particle.The assigned strength is then used for crush detection by comparing it with its maximum tensile stress.Mass conservation is ensured by inserting a series of sub-particles whose total mass was equal to the quality loss.Based on the crushable DEM framework,a numerical simulation of the crushing behavior of a pebble bed with hollow cylindrical geometry under a uniaxial compression test was performed.The results of this investigation showed that the particle withstands the external load by contact and sliding at the beginning of the compression process,and the results confirmed that crushing can be considered an important method of resisting the increasing external load.A relatively regular particle arrangement aids in resisting the load and reduces the occurrence of particle crushing.However,a limit exists to the promotion of resistance.When the strain increases beyond this limit,the distribution of the crushing position tends to be isotropic over the entire pebble bed.The theoretical model and crushable DEM framework provide a new method for exploring the pebble bed in a fusion reactor,considering particle crushing. 展开更多
关键词 Crushing behavior Granular material Discrete element method Pebble bed Fractal theory
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Design and mechanical characterization of discretely assembled mechanical metamaterials for macroscale applications 认领 引用
20
作者 Zhengtao Shu Ying Zhou +2 位作者 Junjian Fu Hao Li Liang Gao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2026年第2期80-94,共15页
Manufacturing large-scale mechanical metamaterials(MMs) is extremely challenging owing to the limitations of machining technology and equipment.This study proposes a family of discretely assembled MMs to address this ... Manufacturing large-scale mechanical metamaterials(MMs) is extremely challenging owing to the limitations of machining technology and equipment.This study proposes a family of discretely assembled MMs to address this issue.In this work,six types of MM unit cells are divided into several face blocks,which can be mass-produced by traditional low-cost manufacturing processes.The discrete face blocks are then assembled using connectors and fasteners to form a unit cell.These assembled unit cells can be further discretely assembled for modular constructions and reconfigurable MM structure systems.The results show that the discretely assembled MMs exhibit excellent mechanical properties such as high stiffness,compression resistance,and auxetic and chiral behaviors.In addition,two typical application scenarios and an example show that the discrete assembly strategy provides accessibility for the heterogeneous and multi-material assemblies of MMs.The discrete assembly strategy,benefiting from the incremental assembly feature,is proven to be a low-cost and highly repeatable forming process.It provides scalability and functionality that are not achievable with traditional manufacturing techniques.Combined with advanced design methods and automated assembly processes,discretely assembled MMs will be significant in future intelligent structures,soft robotics,and aerospace. 展开更多
关键词 Discrete assembly Mechanical metamaterials Modular and reconfigurable system Mass production Large-scale forming
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