期刊文献+
共找到644,102篇文章
< 1 2 250 >
每页显示 20 50 100
Transverse vibration of the blade for unmanned micro helicopter using rayleigh-ritz method 认领 引用
1
作者 Jungang Lii, Jiadao Wang, and Darong ChenState Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China 《Journal of University of Science and Technology Beijing》 2003年第6期40-43,共4页
A rotor manipulation mechanism for micro unmanned helicopter utilizing the inertia and the elasticity of the rotor is introduced. The lagging motion equation of the rotor blades is established, and then the natural fr... A rotor manipulation mechanism for micro unmanned helicopter utilizing the inertia and the elasticity of the rotor is introduced. The lagging motion equation of the rotor blades is established, and then the natural frequencies and mode shapes of the blade for the helicopter are studied by using beam characteristic orthogonal polynomials by the Rayleigh-Ritz method. The variation of natural frequencies with the speed of rotation and the mode shapes at different rotational speeds are plotted. The using of orthogonal polynomials for the bending shapes enables the computation of higher natural frequencies of any order to be accomplished without facing any difficulties. 展开更多
关键词 rotor manipulation mechanism rotor blades Rayleigh-Ritz method
暂未订购 下载PDF
Free vibration analysis of non-homogeneous orthotropic plates resting on Pasternak elastic foundation by Rayleigh-Ritz method 认领 引用 被引量:2
2
作者 Ahmad Rahbar-Ranji Arash Shahbaztabar 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第2期413-420,共8页
Free vibration analysis of non-homogeneous orthotropic plates resting on a Pasternak type of elastic foundation is investigated. A set of admissible orthogonal polynomials are generated with Gram-Schmidt orthogonaliza... Free vibration analysis of non-homogeneous orthotropic plates resting on a Pasternak type of elastic foundation is investigated. A set of admissible orthogonal polynomials are generated with Gram-Schmidt orthogonalization procedure and adopted in the Rayleigh-Ritz method. Accuracy and applicability of the method are examined by comparison of the results for different boundary conditions and material types with those available in literature. It is found that this method has good accuracy regardless of type of boundary condition and yields very accurate results even with low number of terms of orthogonal polynomials for the first mode of vibration. For higher modes of vibration, higher terms of orthogonal polynomials should be used. The effects of foundation parameter, density and non-homogeneity parameters on natural frequency are examined. It is concluded that natural frequency of plates are more sensitive to shearing layer coefficient rather than Winkler coefficient and density parameter has weakening effect on natural frequency. 展开更多
关键词 free vibration non-homogeneous orthotropic plate Pastemak foundation Rayleigh-Ritz method Gram-Schmidt procedure
暂未订购 下载PDF
Broadband ground motion simulation and analysis of a near-fault 3D basin-mountain coupling site based on the hybrid method 认领 引用 被引量:1
3
作者 Liu Zhongxian Tang Kang +2 位作者 Li Chengcheng Yuan Xiaoming Zhang Hai 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2026年第1期87-110,共24页
This study presents an effective hybrid simulation approach for simulating broadband ground motion in complex near-fault locations.The approach utilizes a deterministic approach based on the spectral element method(SE... This study presents an effective hybrid simulation approach for simulating broadband ground motion in complex near-fault locations.The approach utilizes a deterministic approach based on the spectral element method(SEM),which is used to simulate low-frequency ground motion(f1 Hz).A fourth-order Butterworth filter with zero phase shift is employed for time-domain filtering of low-and high-frequency time series at a crossover frequency of 1 Hz,merging the low and high-frequency ground motions into a broadband time series.Taking an Ms 6.8 Luding earthquake,as an example,this hybrid method was used for a rapid and efficient simulation analysis of broadband ground motion in the region.The accuracy and efficiency of this hybrid method were verified through comparisons with actually observed station data and empirical attenuation curves.Deterministic method simulation results revealed the effects of mountainous topography,basin effects,nonlinear effects within the basin’s sedimentary layers,and a coupling interaction between the basin and the mountains.The findings are consistent with similar studies,showing that near-fault sedimentary basins significantly focus and amplify strong ground motion,and the soil’s nonlinear behavior in the basin influences ground motion to varying extents at different distances from the fault.The mountainous topography impacts the basin’s response to ground motion,leading to barrier effects.This research provides a scientific foundation for seismic zoning,urban planning,and seismic design in nearfault mountain basin regions. 展开更多
关键词 hybrid ground motion simulation method spectral element method three-dimensional stochastic finite fault method near-fault basin-mountain coupling effect basin effect nonlinear effect
暂未订购 下载PDF
Methods of preparation,structural characteristics of resistant starch and its relation to human health:a review 认领 引用 被引量:1
4
作者 Weiyi Zhang Yang Yang +6 位作者 Chunmin Ma Bing Wang Xiaofei Liu Yan Wang Xin Bian Guang Zhang Na Zhang 《Food Science and Human Wellness》 SCIE CAS CSCD 2026年第4期1503-1519,共17页
Resistant starch(RS)comprises starch fractions that resist digestion in the small intestine and reach the colon,where they are fermented by the microbiota.Resistant starch harbors functional properties and healthpromo... Resistant starch(RS)comprises starch fractions that resist digestion in the small intestine and reach the colon,where they are fermented by the microbiota.Resistant starch harbors functional properties and healthpromoting ingredients that can regulate blood glucose and lipid levels,prevent cancer,and enhance the quality of life.Consequently,new technologies for the preparation of RS are continually being developed to support its industrial production.This review describes the structural and nutritional properties of RS and examines recent advancements in RS preparation methods.Emphasis is placed on how RS structure influences its properties and the physiological mechanisms in vivo.This review aims to stimulate further research into the preparation methods,functional characteristics,and utilization of RS,thereby supporting ongoing developments in the food industry. 展开更多
关键词 Resistant starch Preparation methods Characterization Function Human health
暂未订购 下载PDF
Development of nontarget method based on GC-QTOF-HRMS for analyzing organic pollutants in human serum 认领 引用 被引量:1
5
作者 Congcong Yue Chang He +5 位作者 Hailing Li Zhiquan Yuan Guiying Li Shengtao Ma Xin Zhang Taicheng An 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第7期379-386,共8页
Traditional targeted analyses often overlook unknown or emerging contaminants,highlighting the significance of nontarget and suspect screening approaches.A novel and high-sensitivity methodology for nontarget analysis... Traditional targeted analyses often overlook unknown or emerging contaminants,highlighting the significance of nontarget and suspect screening approaches.A novel and high-sensitivity methodology for nontarget analysis of organic pollutants in human serum was newly-developed based on gas chromatography coupled with quadrupole time-of-flight high-resolution mass spectrometry.The extraction protocol employing an acetonitrile-ethyl acetate(9:1,V:V)mixture significantly improved the extraction efficiency while minimizing matrix effect.A hybridized analytical strategy integrating nontarget and suspect screening was developed to achieve comprehensive identification and classification of pollutants,employing the National Institute of Standards and Technology(NIST)20 library and Agilent Technologies Personal Compound Database and Library(PCDL).This approach successfully characterized 273 organic contaminants spanning 12 categories,including polycyclic aromatic hydrocarbons(PAHs)and their derivatives,esters,and phenolic compounds in human serum,with a significant increase in detection specificity compared to conventional workflows.The methodology used serum samples of the workers from coking industry,revealing widespread contamination dominated by PAHs and PAH derivatives.Among the target analytes,three were identified solely by NIST and six solely by PCDL,indicating the complementary benefits of combining these different databases.Notably,this work reported the first confirmed detection of 2-naphthalenamine in human serum.This optimized approach demonstrates enhanced sensitivity and reliability in serum analysis,advancing biomonitoring capabilities and providing a deep understanding of human exposure to environmental pollutants. 展开更多
关键词 Nontarget analysis Biomonitoring method Human serum sample Organic pollutants GC-QTOF-HRMS
暂未订购 下载PDF
Implicit unified gas kinetic particle method for steady-state solution of multiscale phonon transport 认领 引用 被引量:2
6
作者 Hongyu Liu Xiaojian Yang +2 位作者 Chuang Zhang Xing Ji Kun Xu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第2期496-510,共15页
This paper presents a highly efficient implicit unified gas-kinetic particle(IUGKP)method for obtaining steady-state solutions of multi-scale phonon transport.The method adapts and reinterprets the integral solution o... This paper presents a highly efficient implicit unified gas-kinetic particle(IUGKP)method for obtaining steady-state solutions of multi-scale phonon transport.The method adapts and reinterprets the integral solution of the Bhatnagar-Gross-Krook(BGK)equation for time-independent solutions.The distribution function at a given point is determined solely by the surrounding equilibrium states,where the corresponding macroscopic quantities are computed through a weighted sum of equilibrium distribution functions from neighboring spatial positions.From a particle perspective,changes in macroscopic quantities within a cell result from particle transport across cell interfaces.These particles are sampled according to the equilibrium state of their original cells,accounting for their mean free path as the traveling distance.The IUGKP method evolves the solution according to the physical relaxation time scale,achieving high efficiency in large Knudsen number regimes.To accelerate convergence for small Knudsen numbers,an inexact Newton iteration method is implemented,incorporating macroscopic equations for convergence acceleration in the near-diffusive limit.The method also addresses spatial-temporal inconsistency caused by relaxation time variations in physical space through the null-collision concept.Numerical tests demonstrate the method’s excellent performance in accelerating multi-scale phonon transport solutions,achieving speedups of one to two orders of magnitude.The IUGKP method proves to be an efficient and accurate computational tool for simulating multiscale non-equilibrium heat transfer,offering significant advantages over traditional methods in both numerical performance and physical applicability. 展开更多
关键词 Implicit gas kinetic particle method Phonon Boltzmann transport equation Multi-scale heat conduction Steady-state
暂未订购 下载PDF
Prediction method for stationary crossflow instability transition in supersonic boundary layers based on multi-layer perceptron 认领 引用 被引量:2
7
作者 Lei Qiao Xi Jiang +5 位作者 Jiakun Fan Yutian Wang Lu Xie Ningjuan Dong Jiakuan Xu Junqiang Bai 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第7期36-51,共16页
Crossflow vortices induced transition is one of the most important instability types in supersonic aircraft boundary layers.While the traditional linear stability theory(LST)-based eN method demonstrates satisfactory ... Crossflow vortices induced transition is one of the most important instability types in supersonic aircraft boundary layers.While the traditional linear stability theory(LST)-based eN method demonstrates satisfactory predictive capabilities for this kind of transition,its practical implementation faces inherent limitations:the requirement of first-and second-order wallnormal derivatives of boundary layer velocityemperature profiles,the need for initial eigenvalue guesses,and the computational burden of solving eigenvalue problems.To address these challenges,this study develops a multi-layer perceptron(MLP)model tailored for linear stability analysis of three-dimensional compressible boundary layers based on the artificially defined quasi-three-dimensional non-similar boundary layer solutions.The boundary layer edge flow parameters and perturbation characteristics are mapped to eigenvalues or local growth rates of the envelop curves through fully connected layers.This architecture eliminates the need for computing wall-normal derivatives of velocityemperature profiles,initial eigenvalue estimation,and direct eigenvalue problem solving.Extensive validation across varying operational conditions and geometries(airfoils and swept wings)demonstrates exceptional agreement between the MLP’s predictions(eigenvalues and disturbance amplification factors)and traditional LST results.Furthermore,the model’s transition prediction capability is rigorously verified using National Aeronautics and Space Administration’s supersonic swept-wing crossflow-dominated transition benchmark,incorporating both stability analysis and flight test data.Results confirm the model is an efficient and reliable computational framework for transition prediction in three-dimensional finite-span wings. 展开更多
关键词 Supersonic swept wing Boundary layer transition Crossflow instability Linear stability theory eN method Multi-layer perceptron
暂未订购 下载PDF
Environmental Contour Methods for Long-Term Extreme Response Prediction of Offshore Wind Turbines 认领 引用 被引量:1
8
作者 Jixiang Zhang Shan Wang +4 位作者 Milad Shadman Mojtaba Maali Amiri Baiqiao Chen Chen An Segen Farid Estefen 《哈尔滨工程大学学报(英文版)》 CSCD 2026年第2期473-490,共18页
The long-term responses of offshore wind turbines(OWTs)are critical in the design phase,where precise assessments ensure structural reliability and operational efficiency.The environmental contour method(ECM)enables e... The long-term responses of offshore wind turbines(OWTs)are critical in the design phase,where precise assessments ensure structural reliability and operational efficiency.The environmental contour method(ECM)enables efficient analysis of design responses by focusing on a selected set of critical environmental conditions that predominantly drive long-term extreme responses.Despite its extensive use in offshore engineering,ECM’s application in the structural design and strength assessment of OWTs remains underexplored.This study offers a comprehensive overview of the utilization of ECM in the context of OWT design,incorporating a bibliometric analysis of publications from the Web of Science to identify research trends and key topics.The analysis highlights diverse approaches for estimating long-term extreme responses and constructing environmental contours using statistical distributions.Additionally,the study explores the application of ECM and its modified versions in the design and strength assessment of OWTs.Challenges and opportunities associated with ECM implementation in OWTs are critically analyzed,providing insights into ECM’s potential for enhancing the efficiency and reliability of OWT structural design. 展开更多
关键词 Environmental contour method Offshore wind turbine Long-term extreme response Reliability
暂未订购 下载PDF
Antibody screening for tumor and immune hotspot targets:The frontier of new methods and technologies 认领 引用 被引量:1
9
作者 Yaping Zhou Yitan Zou +6 位作者 Shaodong Lv Dan Tan Guangyao Li Wenyan Fu Changhai Lei Mingdong Lu Shi Hu 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2026年第2期393-412,共20页
Advancements in tumor immunotherapy highlight the significant potential of antibody drugs,a key category of biological agents,for treating cancer and autoimmune diseases.This paper begins by defining and classifying k... Advancements in tumor immunotherapy highlight the significant potential of antibody drugs,a key category of biological agents,for treating cancer and autoimmune diseases.This paper begins by defining and classifying key targets in tumor immunity,as well as discussing their structural and functional characteristics.Subsequently,it elaborates on innovative technologies for antibody drug screening,which,when integrated with contemporary molecular biology,biotechnology,and computational biology,have substantially enhanced the efficiency and accuracy of target identification and antibody drug screening processes.Despite the promising prospects of tumor immunotherapy,certain limitations persist in its practical implementation.In conclusion,this paper offers a comprehensive examination of the cutting-edge developments in tumor immunotherapy,focusing on the aspects of tumor immunotherapy itself,critical targets for immunotherapy,and novel technologies and methodologies for antibody screening.This analysis is crucial for advancing the field of tumor immunotherapy and for enhancing both therapeutic efficacy and safety.Furthermore,research and development(R&D)of antibody drugs in other domains,such as autoimmune and inflammatory diseases,can benefit from it. 展开更多
关键词 Tumor immunotherapy Hotspot targets Antibody drug screening Target discovery Innovative technologies and methods
暂未订购 下载PDF
A physics-based probabilistic method for assessment of landslide-induced wave run-up hazards 认领 引用 被引量:2
10
作者 Ningjie Li Xinli Hu +3 位作者 Jian Wang Junxiang Huang Hongchao Zheng Wei Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第5期3675-3687,共13页
Traditional deterministic numerical simulation often has a poor prediction performance for landslide-induced wave run-up(LIWR)hazards,as it neglects the effects of uncertainty.The limitation for efficiently quantifyin... Traditional deterministic numerical simulation often has a poor prediction performance for landslide-induced wave run-up(LIWR)hazards,as it neglects the effects of uncertainty.The limitation for efficiently quantifying the uncertainties in primary parameters remains largely unsolved.In this study,we propose a probabilistic evaluation method,integrating the adaptive Kriging(AK)metamodel method and probability density evolution method(PDEM)based on generalized F-discrepancy.A Taylor expansion-based adaptive design strategy is applied to construct the global AK model over representative points generated by generalized F-discrepancy,thereby approximating the numerical physical response(i.e.,maximum LIWR).Using these approximate responses,the PDEM is used to compute the exceedance probabilities that LIWR heights exceed elements at risk based on a construction of virtual time,and then a probabilistic criterion is introduced to classify hazard zones.The proposed method is demonstrated via two examples:Example I,which possesses risk element(building),and Example Ⅱ with water-level variations.The results indicate that the proposed method has an acceptable performance(showing a 1.7%difference in exceedance probability compared to Monte Carlo simulation with 50,000 samples)with low computation cost(requiring 284 deterministic analyses).For two specific scenarios in this study,the wave induced by the landslide exhibits a solitary-like leading wave.The proposed probabilistic method provides promising prospects for quantifying LIWR uncertainties,and is helpful for direct,efficient,and low-cost quantification assessment of cascading hazards. 展开更多
关键词 Landslide-induced wave run-up(LIWR) Numerical simulation Adaptive metamodel Probability density evolution method(PDEM) Hazard zoning
暂未订购 下载PDF
A method of characteristics for supersonic viscous flows 认领 引用 被引量:1
11
作者 Bo ZHANG Yuxin ZHAO Shihe YI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第3期282-293,共12页
This paper develops a method of characteristics for supersonic viscous flows.The proposed method removes the inviscid and isentropic assumptions of the classical method of characteristics.The characteristic equations ... This paper develops a method of characteristics for supersonic viscous flows.The proposed method removes the inviscid and isentropic assumptions of the classical method of characteristics.The characteristic equations and compatibility equations are derived from the governing equations for compressible viscous flow.By combining the characteristic lines,the triangular interior unit process,quadrilateral interior unit process,and direct sonic point unit process are developed.The unit processes make up the characteristic net.The numerical algorithms consider the path of flow signal propagation.The inviscid terms are solved along characteristic lines,while the viscous terms are corrected through iterative whole-field computations.The proposed method has been applied to supersonic flat-plate boundary layer and verified by the similarity solution.The errors of velocity and temperature profiles are on the order of 0.1%,while the computation efficiency is the same as the classical method of characteristics.The accuracy and efficiency make the proposed method potential to become a basic tool of analysis and design for supersonic viscous flows. 展开更多
关键词 Characteristic line Compatibility equation Compressible flow Method of characteristics Supersonic flow Viscous flow
暂未订购 下载PDF
Aeroelastic characteristics and vibration reduction method of NTBT rotor with TEF technology 认领 引用 被引量:1
12
作者 Hualong WANG Xiayang ZHANG +4 位作者 Qijun ZHAO Li MA Wei BIAN Shiming LIU Yuan GONG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第2期263-282,共20页
A high-precision CFD/CSD(Computational Fluid Dynamics/Computational Structural Dynamics)coupling method is developed to study the aeroelastic behavior and design the vibration reduction strategy of NTBT(New Type Blade... A high-precision CFD/CSD(Computational Fluid Dynamics/Computational Structural Dynamics)coupling method is developed to study the aeroelastic behavior and design the vibration reduction strategy of NTBT(New Type Blade-Tip)rotor with TEF(Trailing Edge Flap)technology in forward flight.In the aspect of CSD method,the closed-form dynamical governing equation is modified using Hamilton’s principle to consider the influence of the movable TEF,in which the NTBT geometric nonlinearity is considered through coordinate transformation by virtue of finite element method.In the aspect of CFD method,a moving-embedded grid method for rotor blades is developed to account for the dynamic deflection of TEF,in which the grid deformation is achieved through algebraic transformations,and a high-precision unsteady CFD method with 5th-order TENO(Targeted Essentially Non-Oscillatory)scheme is introduced to effectively simulate the rotor flowfield.Considering the computational efficiency,the loosely-coupling strategy is introduced to build up the CFD/CSD method.The validity of the coupling method is verified by comparing the computed aerodynamic loads,frequency spectrum,and structural loads with the referential or the experimental results of the typical model rotors.Based on that,the frequency,phase,and amplitude-sweeping parametric analyses of TEF are conducted thoroughly to reveal the influence mechanisms on the aeroelastic characteristics of NTBT rotor.Furthermore,an optimal control strategy is proposed to suppress the vibration intensity of hub loads,showing that the active vibration reduction method can effectively suppress the rotor hub vibratory intensity by over 40%in typical forward flight conditions. 展开更多
关键词 CFD/CSD method NTBT geometry Rotor aeroelasticity Trailing Edge Flap(TEF) Vibration reduction
暂未订购 下载PDF
Correction models of Reynolds number effects for through-flow method in axial compressors 认领 引用 被引量:1
13
作者 Xiaochen WANG Chunwei GU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第1期78-94,共17页
Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages ha... Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages have difficulties in predicting comprehensively Reynolds number effects on airfoils,matching and characteristics curves.This study proposes Re-correction models for loss,deviation angle and endwall blockage based on classical theories and cascade tests,and loss and deviation models show good agreement in test data of NACA65 and C4 cascades.Throughflow method considering Reynolds number effects is developed by integrating the correction models into a verified Streamline Curvature(SLC)tool.A three-stage axial compressor is investigated through SLC and CFD methods from design Reynolds number(Red=2106)to low Re=4104,and the numerical methods are validated with test data of characteristic curves and spanwise distributions at Red.With Re reduction,SLC method with correction models well predicts variation in overall performances compared with CFD calculations and Wassell's model.Streamwise and spanwise matching such as total pressure and loss distributions in SLC predictions are basically consistent with those in CFD results at near-stall points under design and low Reynolds numbers.SLC and CFD methods share similar detections of stall risks in the third stage(Stg3),and their analyses of diffusion processes deviate to some extent due to different predictions in separated endwall flow.The correction models can be adopted to consider Reynolds number effects in through-flow design and analysis of axial compressors. 展开更多
关键词 Axial compressor Reynolds number effects Correction model Through-flow method Aerodynamic performance
暂未订购 下载PDF
A Comparative Study of State-of-the-Art Meshless Methods for Flow and Transport Simulation in Porous Media 认领 引用
14
作者 T.I.Eldho Sanjukta Das +1 位作者 Aatish Anshuman Tinesh Pathania 《Computer Modeling in Engineering & Sciences》 SCIE EI 2026年第5期828-852,共25页
In recent years,meshless methods have been increasingly applied to the simulation of various engineering problems due to their inherent advantages over traditional mesh-based approaches,including greater flexibility,i... In recent years,meshless methods have been increasingly applied to the simulation of various engineering problems due to their inherent advantages over traditional mesh-based approaches,including greater flexibility,independence from predefined meshing,simpler adaptive analysis,improved automation,and suitability for complex problems.Several meshless methods have been used for porous media simulation,and are broadly categorized into collocation,global weak form and local weak form methods.In this study,a comprehensive comparison of the applicability of these three categories of meshless methods for simulating coupled flow and transport problems in porous media is presented.The Radial Point Collocation Method(RPCM)(strong form),the Element Free Galerkin Method(EFGM)(global weak form)and the Meshless Local Petrov Galerkin(MLPG)method(local weak form)are implemented and systematically compared.These methods are applied to the analysis of flow in a synthetic regular domain aquifer,flow and non-reactive contaminant transport in a synthetic irregular boundary porous media problem and groundwater flow in a field aquifer located in India.The simulated groundwater heads are compared with analytical solution,observed field data and results obtained from widely used MODFLOW-MT3DMS models.The deviation of the solutions from the analytical solution is in the range of O.67%to O.l6%for the hypothetical case study.For the field-scale case study,mean absolute error of 0.183%,0.18l%and 0.188%are obtained for the RPCM,EFGM and MLPG models,respectively,outperforming MODFLOW,which exhibits a deviation of 0.254%from observed values.Overall,the present study reaffirms the practical applicability of these meshless methods for real-world groundwater problems and provides valuable insights into the utilization of each category of meshless method,with respect to problem type,computational efficiency and accuracy requirements. 展开更多
关键词 Meshless methods groundwater flow contaminant transport radial point collocation method element free Galerkin method meshless local Petrov Galerkin method
暂未订购 下载PDF
Tunnel ahead prospecting methods and intelligent interpretation of adverse geology:A review 认领 引用 被引量:1
15
作者 Shucai Li Bin Liu +4 位作者 Lei Chen Huaifeng Sun Lichao Nie Zhengyu Liu Yuxiao Ren 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第1期1-19,共19页
Geological prospecting and the identification of adverse geological features are essential in tunnel construction,providing critical information to ensure safety and guide engineering decisions.As tunnel projects exte... Geological prospecting and the identification of adverse geological features are essential in tunnel construction,providing critical information to ensure safety and guide engineering decisions.As tunnel projects extend into deeper and more mountainous terrains,engineers face increasingly complex geological conditions,including high water pressure,intense geo-stress,elevated geothermal gradients,and active fault zones.These conditions pose substantial risks such as high-pressure water inrush,largescale collapses,and tunnel boring machine(TBM)blockages.Addressing these challenges requires advanced detection technologies capable of long-distance,high-precision,and intelligent assessments of adverse geology.This paper presents a comprehensive review of recent advancements in tunnel geological ahead prospecting methods.It summarizes the fundamental principles,technical maturity,key challenges,development trends,and real-world applications of various detection techniques.Airborne and semi-airborne geophysical methods enable large-scale reconnaissance for initial surveys in complex terrain.Tunnel-and borehole-based approaches offer high-resolution detection during excavation,including seismic ahead prospecting(SAP),TBM rock-breaking source seismic methods,fulltime-domain tunnel induced polarization(TIP),borehole electrical resistivity,and ground penetrating radar(GPR).To address scenarios involving multiple,coexisting adverse geologies,intelligent inversion and geological identification methods have been developed based on multi-source data fusion and artificial intelligence(AI)techniques.Overall,these advances significantly improve detection range,resolution,and geological characterization capabilities.The methods demonstrate strong adaptability to complex environments and provide reliable subsurface information,supporting safer and more efficient tunnel construction. 展开更多
关键词 Tunnel geological ahead prospecting Complex geological and environmental conditions Airborne geophysical methods Tunnel geophysical detection Borehole geophysical prospecting Intelligent geological interpretation
暂未订购 下载PDF
A Review on Circumferential Crack Method Used for Simulating Ice-Structure Interaction 认领 引用 被引量:3
16
作者 ZHOU Li 《China Ocean Engineering》 SCIE EI CSCD 2026年第1期1-14,共14页
Structure-ice interaction problems have attracted increasing attention,yet accurately predicting the loads exerted by sea ice on ship hulls remains a significant challenge.Over the past few decades,various numerical m... Structure-ice interaction problems have attracted increasing attention,yet accurately predicting the loads exerted by sea ice on ship hulls remains a significant challenge.Over the past few decades,various numerical methods have been employed to simulate ice resistance on ships and evaluate their manoeuvrability during ice-structure interaction.Among these approaches,the circumferential crack method has demonstrated both high efficiency and accuracy.This paper provides a detailed introduction to the fundamental theory of this method,including the numerical modeling of different failure modes and the dynamic ice motion responses.Furthermore,it reviews existing studies on predicting ice resistance and assessing the manoeuvrability of icebreakers navigating through ice-covered regions using the circumferential crack method.Several recommendations for future research in this field are also presented. 展开更多
关键词 ice forces circumferential crack method ice resistance ice-structure interaction ice failure modes polar ship
暂未订购 下载PDF
Investigation of dynamic seismic response in liquid-containing structures for nuclear reactors using the hybrid Eulerian-Lagrangian method 认领 引用
17
作者 Shi-Lin Chen Qing-Xi Yang +3 位作者 Qing-Zhou Yu Hao Xu Jian Chen Zhao-Xi Chen 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第6期159-177,共19页
Liquid-containing structures,including steam generators,water-cooling systems,in-containment refueling water storage tanks,suppression tanks,and tritiated water storage facilities,are integral components of nuclear re... Liquid-containing structures,including steam generators,water-cooling systems,in-containment refueling water storage tanks,suppression tanks,and tritiated water storage facilities,are integral components of nuclear reactor systems and are crucial for ensuring operational safety and stability.Traditional seismic analysis methods often struggle to accurately predict the dynamic behavior of such structures,particularly under transient events such as earthquakes.This paper presents a comprehensive study that applies the hybrid Eulerian-Lagrangian method to analyze fluid-structure interactions within these structures.The efficacy of this method for capturing the complex dynamics induced by liquid movement is demonstrated through simulations conducted primarily in a vertical storage tank.A comparative analysis with traditional response-spectrum analysis methods underscores the limitations of conventional approaches,particularly in terms of accounting for nonlinear free-surface motions and dynamic velocity distributions.The structural response of the tank containing liquid calculated using the hybrid Eulerian-Lagrangian method is approximately twice that calculated using the response-spectrum method,whereas in the case of a tank without liquid,the response is the same.Additionally,a high dynamic stress distribution exists near the liquid level of the structure.This study addresses the intricate interplay between structural components and fluid dynamics,thereby extrapolating insights from tanks to enhance safety protocols and design considerations for future nuclear devices. 展开更多
关键词 Liquid-containing structures Nuclear reactors Seismic analysis methods Hybrid Euler-Lagrangian method Complex dynamics
暂未订购 下载PDF
Comparison and applications of solid weighting functions for fluid-particle modeling using the lattice Boltzmann-discrete element coupling method 认领 引用
18
作者 Duo Wang Yuman Han +5 位作者 Yi Zheng Songyan Wang Xiaofang Jiang Shiyi Jiang Mengdi Sun Zhejun Pan 《Theoretical & Applied Mechanics Letters》 EI CAS CSCD 2026年第3期73-82,共10页
This paper presents a comparative study of the solid weighting functions within the text of the modified partially saturated method(MPSM),which is an effective fluid-solid boundary condition in the lattice Boltzmann-d... This paper presents a comparative study of the solid weighting functions within the text of the modified partially saturated method(MPSM),which is an effective fluid-solid boundary condition in the lattice Boltzmann-discrete element coupling method(LBM-DEM).In its original form,the solid weighting function is τ-dependent.Previous studies have shown that the computational drag is viscosity-dependent when using the τ-dependent solid weighting function to solve fluid-particle interactions.To address this issue,two modified solid weighting functions,namely,the higher-order function and the solid-coverage function,are proposed.Nevertheless,the literature lacks a comparison of these functions,especially for viscosity dependence.In this study,the solid weighting functions are implemented and tested through two benchmark multiphase configurations,i.e.,a sphere settling between two parallel plates and the‘drafting,kissing and tumbling’of two settling spheres.The computational accuracy,viscosity dependence and convergence of the two modified functions are validated and compared against the original τ-dependent function.The LBM-DEM-MPSM formulation is then applied to study the settling behavior of a particle pack with varying solid fractions in a narrow fracture,which highlights the potential of employing the LBM-DEM-MPSM approach to a broader range of fluid-particle systems. 展开更多
关键词 Lattice boltzmann method Discrete element method Fluid-solid boundary conditions Fluid-particle interaction particle settling
暂未订购 下载PDF
Moment flux-based discrete velocity method based on the Boltzmann-BGK equations along the characteristic line 认领 引用
19
作者 Wei Liu Yong Liu Haihu Liu 《Theoretical & Applied Mechanics Letters》 EI CAS CSCD 2026年第3期110-120,共11页
This paper introduces an improved scheme based on the discrete velocity method.Specifically,the reconstruction of the velocity distribution function and numerical flux at the interface is founded on the solution of th... This paper introduces an improved scheme based on the discrete velocity method.Specifically,the reconstruction of the velocity distribution function and numerical flux at the interface is founded on the solution of the Bhatnagar-Gross-Krook equation along the characteristic line.The proposed method accurately considers molecular transport and collision effects at the interface,thereby enabling accurate modeling from rarefied to continuum flow regimes.Additionally,the implicit discretization of the microscopic equations and incorporation of macroscopic equations result in accelerated convergence properties for steady-state problems.The proposed numerical approach is validated through several cases,including Rayleigh flow,lid-driven cavity flow,flow past an NACA0012 airfoil,and supersonic flow around a sphere.Numerical results demonstrate that the proposed method can efficiently and accurately obtain multiscale flow properties. 展开更多
关键词 Rarefied flow Boltzmann equation Moment method Finite volume method
暂未订购 下载PDF
The order of accuracy related to the error from source approximation in the method of characteristics for purely absorbing materials in planar geometry 认领 引用
20
作者 Ji-Pu Wang Zhen-Wen Wei +5 位作者 Can Huang William Martin Brendan Kochunas Qi-Cang Shen Si-Juan Chen Martin Pilch 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第6期257-270,共14页
The method of characteristics(MoC)is a well-established tool for lattice physics calculations,offering advantages such as accurate representation of both lattice geometry and boundary conditions.The flat source(FS)app... The method of characteristics(MoC)is a well-established tool for lattice physics calculations,offering advantages such as accurate representation of both lattice geometry and boundary conditions.The flat source(FS)approximation is the most commonly used approach,whereas the linear source(LS)approximation enhances the accuracy by preserving the higherorder spatial moments of the neutron source.However,determining the order of accuracy(OoA)for spatial discretization in the MoC is challenging,particularly for the LS approximation.This complexity arises because MoC employs two spatial meshes:the fission source region(FSR)mesh and a set of characteristic rays used to integrate the transport equation over the FSR mesh.In this study,we analyzed the spatial order of accuracy of the MoC in planar geometry for both FS and LS approximations in relation to the distributed source.Our theoretical predictions are consistent with the numerical results obtained using the Method of Manufactured Solutions(MMS).The results demonstrate that the FS approximation achieves second-order accuracy,whereas the LS approximation attains fourth-order accuracy. 展开更多
关键词 Method of characteristics Order of accuracy Flat source approximation Linear source approximation Method of manufactured solutions
暂未订购 下载PDF
上一页 1 2 250 下一页 到第
在线咨询 使用帮助 返回顶部 意见反馈