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Surrogate modeling for unsaturated infiltration via the physics and equality-constrained artificial neural networks

Journal of Rock Mechanics and Geotechnical engineering 2024年第6期16卷 2282-2295页

作者： Peng Lan Jingjing Su Sheng Zhang School of civil engineering Central South UniversityChangsha410075China Discipline of civil Surveying and Environmental EngineeringPriority Research Centre for Geotechnical Science and EngineeringThe University of NewcastleCallaghanNSW2308Australia Qinghai University Qinghai810016China

Machine learning(ML)provides a new surrogate method for investigating groundwater flow dynamics in unsaturated *** pure data-driven methods(*** neural network,DNN)can provide rapid predictions,but they do require sufficient on-site data for accurate training,and lack interpretability to the physical processes within the *** this paper,we provide a physics and equalityconstrained artificial neural network(PECANN),to derive unsaturated infiltration solutions with a small amount of initial and boundary *** takes the physics-informed neural network(PINN)as a foundation,encodes the unsaturated infiltration physical laws(*** equation,RE)into the loss function,and uses the augmented Lagrangian method to constrain the learning process of the solutions of RE by adding stronger penalty for the initial and boundary *** unsaturated infiltration cases are designed to test the training performance of PECANN,***-dimensional(1D)steady-state unsaturated infiltration,1D transient-state infiltration,two-dimensional(2D)transient-state infiltration,and 1D coupled unsaturated infiltration and *** predicted results of PECANN are compared with the finite difference solutions or analytical *** results indicate that PECANN can accurately capture the variations of pressure head during the unsaturated infiltration,and present higher precision and robustness than DNN and *** is also revealed that PECANN can achieve the same accuracy as the finite difference method with fewer initial and boundary training ***,we investigate the effect of the hyperparameters of PECANN on solving RE *** provides an effective tool for simulating unsaturated infiltration.

关键词： Richards equation(RE) Unsaturated infiltration Data-driven solutions Numerical modeling Machine learning(ML)

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Transfer relation between subgrade frost heave and slab track deformation and vehicle dynamic response in seasonally frozen ground

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2024年第2期25卷 130-146页

作者： Juanjuan REN Junhong DU Kaiyao ZHANG Bin YAN Jincheng TIAN MOE Key Laboratory of High-speed Railway engineering Southwest Jiaotong UniversityChengdu610031China School of civil engineering Southwest Jiaotong UniversityChengdu610031China School of civil engineering Central South UniversityChangsha410075China Airport Planning and Design Institute POWERCHINA Kunming Engineering Corporation LimitedKunming650051China

Subgrade frost heave in seasonally frozen ground can greatly influence the safety and smooth running of high-speed trains and the service performance of track *** this study,we used a static model to:(1)investigate track-subgrade frost heave and develop a dynamic model of vehicle-track-subgrade frost heave;(2)explore the transfer relation between subgrade frost heave and track structure deformation;(3)examine the characteristics of interlayer debonding;(4)study the influence of subgrade frost heave on the dynamic response of vehicles in high-speed railways in seasonally frozen regions.A Fourier series was used to fit the frost heave waveform and simulate the behavior of subgrade uneven frost heave using data collected *** results show:(i)The position of frost heave significantly affects the transfer of deformation to a slab *** largest deformation of the track slab,with the amplitude transfer ratio reaching 20%,was recorded when the frost heave occurred near the joint of the base plate.(ii)At the same frost heave amplitude,long-wave frost heave causes smaller deformation and debonding of the track structure than short-wave frost *** the wavelength range of 10-30 m,the main frequency of the acceleration spectral density was concentrated between 3.5 and 3.7 Hz,with larger frost heave wavelengths producing smaller superposition on the vertical acceleration of the vehicle.(ii)The maximum wheel-rail force occurs when the front bogie passes the frost heave peak,with greater frost heave amplitudes producing greater wheel-rail *** these results,we conclude there is a clear need to control the frost heave deformation of the track to reduce the dynamic response of the vehicle and in turn improve train operatSubgrade frost heave in seasonally frozen ground can greatly influence the safety and smooth running of high-speed trains and the service performance of track *** this study,we used a static model to:(1)investigate track`-subgr

关键词： Slab track Subgrade frost heave Transfer relation Vehicle-track-subgrade coupling Dynamic response

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Experimental Investigation of the Operating Characteristics of a Pulsating Heat Pipe with Ultra-Pure Water and Micro Encapsulated Phase Change Material Suspension

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Journal of Thermal Science 2024年第2期33卷 457-468页

作者： SHI Weixiu SU Xiaoyang CHEN Hongdi PAN Lisheng Beijing engineering Research Center of Sustainable Energy and Buildings Beijing University of Civil Engineering and ArchitectureBeijing100044China School of Environment and Energy engineering Beijing University of Civil Engineering and ArchitectureBeijing100044China State Key Laboratory of High Temperature Gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing100190China

The specific heat capacity of working fluid is an important influence factor on heat transfer characteristic of the pulsating heat pipe(PHP).Due to the relatively large specific heat capacity of micro encapsulated phase change material(MEPCM) suspension,a heat transfer performance experimental facility of the PHP was *** heat transfer characteristic with MEPCM suspension of different mass concentrations(0.5% and 1.0%) and ultra-pure water were compared *** was found that when the PHP uses MEPCM suspension as its working fluid,operating stability is impoverished under lower heating power and the operating stability is better under higher heating *** the inclination angle of 90°,the temperature at heating side decreases compared to ultra-pure water and the temperature at heating side decreases with the raising of MEPCM suspension mass *** heat transfer characteristic of the PHP is positively correlated with the inclination angle and the 90° is *** unfavorable effect of the inclination angle decreases with heating power *** the inclination angle is 90°,the PHP with MEPCM suspension at 1.0% of mass concentration has the lowest thermal transfer resistance and followed by ultra-pure water and MEPCM suspension at 0.5% of mass concentration has the highest thermal transfer *** the inclination angles are 60° and30°,the effect of gravity on the flow direction is reduced to 86.6% and 50% of that on the inclination angle of 90°,respectively,and the promoting effect of gravity on the working fluid is further weakened as the inclination angle further *** to the high viscosity of MEPCM suspension,the PHP with ultra-pure water has the lowest heat transfer *** the inclination angles is 60°,the thermal resistance with MEPCM suspension at0.5% of the mass concentration is lower than that at 1.0% at the heating power below 230 *** thermal resistance of MEPCM suspension tends to be simila

关键词： pulsating heat pipe(PHP) micro encapsulated phase change material(MEPCM) heat transfer characteristic inclination angle

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Deformation characteristics and damage ontologies of soft and hard composite rock masses under impact loading

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Journal of Mountain Science 2024年第5期21卷 1715-1727页

作者： LI Jinhua ZHANG Tianyu WU Baolin SU Peili YANG Yang WANG Pan Architectural and civil engineering College Xi’an University of Science and TechnologyXi’an 710054China

As one of the most common occurring geological landforms in deep rock formations, the dynamic mechanical properties of layered composite rock bodies under impact loading have been widely studied by scholars. To study the dynamic properties of soft and hard composite rocks with different thickness ratios, this paper utilizes cement, quartz sand and gypsum powder to construct soft and hard composite rock specimens and utilizes a combination of indoor tests, numerical calculations, and theoretical analyses to investigate the mechanical properties of soft and hard composite rock bodies. The test results reveal that:(1) When the proportion of hard rock increases from 20% to 50%, the strength of the combined rock body increases by 69.14 MPa and 87 MPa when the hard rock face and soft rock face are loaded, respectively;however, when the proportion of hard rock is the same, the compressive strength of the hard rock face impact is 9%-17% greater than that of the soft rock face impact;(2) When a specimen of soft and hard combined rock body is subjected to impact loading, the damage mode involves mixed tension and shear damage, and the cracks generally first appear at the ends of the specimen, then develop on the laminar surface from the impact surface, and finally end in the overall damage of the soft rock part. The development rate and the total number of cracks in the same specimen when the hard rock face is impacted are significantly greater than those when the soft rock face is impacted;(3) By introducing Weibull’s statistical strength theory to establish the damage variables of soft-hard combined rock bodies, combined with the DP strength criterion, the damage model and the Kelvin body are concatenated to obtain a statistical damage constitutive model, which can better fit the full stress-strain curve of soft-hard combined rock body specimens under a single impact load.

关键词： Soft and hard composite rock mass Dynamic properties Split Hopkinson pressure bar(SHPB) Numerical simulation Intrinsic damage model

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Restraint effect of partition wall on the tunnel floor heave in layered rock mass

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Journal of Mountain Science 2024年第7期21卷 2462-2479页

作者： YANG Yunyun HUANG Da ZHONG Zhu LIU Yang PENG Jianbing School of civil and Transportation engineering Hebei University of TechnologyTianjin 300401China College of Geology engineering and Geomatics Chang’an UniversityXi’an 710054China College of civil engineering&Architecture China Three Gorges UniversityYichang 443002China.

The presence of horizontal layered rocks in tunnel engineering significantly impacts the stability and strength of the surrounding rock mass,leading to floor heave in the *** study focused on preparing layered specimens of rock-like material with varying thickness to investigate the failure behaviors of tunnel *** results indicate that thin-layered rock mass exhibits weak interlayer bonding,causing rock layers near the surface to buckle and break upwards when subjected to horizontal *** an increase in the layer thickness,a transition in failure mode occurs from upward buckling to shear failure along the plane,leading to a noticeable reduction in floor heave *** primary cause of significant deformation in floor heave is upward buckling *** address this issue,the study proposes the installation of a partition wall in the middle of the floor to mitigate heave deformation of the rock *** results demonstrate that the partition wall has a considerable stabilizing effect on the floor,reducing the zone of buckling failure and minimizing floor heave *** is crucial for the partition wall to be sufficiently high to prevent buckling failure and ensure *** simulation calculations on an engineering example,it is confirmed that implementing a partition wall can effectively reduce floor heave and enhance the stability of tunnel floor.

关键词： Layered rock Floor heave Horizontal compression test Failure behavior Partition wall

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Determination of ice jam thickness—A new approach

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Journal of Hydrodynamics 2024年第3期36卷 570-581页

作者： Jun Wang Lian-sheng Sang Fei-hu Song Tie-jie Cheng Jueyi Sui School of civil and Water engineering Hefei University of TechnologyHefei230009China School of engineering University of Northern British ColumbiaPrince GeorgeCanada

In winter,rivers in cold regions often experience flood disasters resulted from ice jams or ice *** of the variation of ice jam thickness and water level during an ice jammed period are not only a practical need for ice prevention to avoid disaster and plan water resource,but also essential for the development of any mathematical model for predicting the evolution of ice *** far,some equations based on the energy equation have been proposed to describe the relationship between ice jam thickness and water ***,in the derivation of these equations,the local head loss coefficient at the ice jam head and the riverbed slope factor were ***,those reported equations cannot be used to preciously describe the flow energy equation with ice jams and accurately calculate the ice jam thickness and water *** the present study,a more comprehensive theoretical model for hydraulic calculation of ice jam thickness has been derived by considering important and essential factors including riverbed slope and local head loss coefficient at the ice jam ***,based on the data collected from laboratory experiments of ice jam accumulation,the local head loss coefficient at the ice jam head has been calculated,and the empirical equation for calculating the local head loss coefficient has been established by considering flow Froude number and the ratio of ice discharge to flow *** results of this study not only provide a new reference for calculating ice jam thickness and water level,but also present a theoretical basis for accurate CFD simulation of ice jams.

关键词： Energy equation ice jam thickness local head loss coefficient ice jam head riverbed slope

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Modeling the Interaction between Vacancies and Grain Boundaries during Ductile Fracture

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Computer Modeling in engineering & Sciences 2024年第8期140卷 2019-2034页

作者： Mingjian Li Ping Yang Pengyang Zhao Department of engineering Mechanics School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

The experimental results in previous studies have indicated that during the ductile fracture of pure metals,vacancies aggregate and form voids at grain ***,the physical mechanism underlying this phenomenon remains not fully *** study derives the equilibrium distribution of vacancies analytically by following thermodynamics and the micromechanics of crystal *** derivation suggests that vacancies cluster in regions under hydrostatic compression to minimize the elastic strain ***,a finite element model is developed for examining more general scenarios of interaction between vacancies and grain *** model is first verified and validated through comparison with some available analytical solutions,demonstrating consistency between finite element simulation results and analytical solutions within a specified numerical accuracy.A systematic numerical study is then conducted to investigate the mechanism that might govern the micromechanical interaction between grain boundaries and the profuse vacancies typically generated during plastic *** simulation results indicate that the reduction in total elastic strain energy can indeed drive vacancies toward grain boundaries,potentially facilitating void nucleation in ductile fracture.

关键词： Ductile fracture vacancy grain boundary micromechanical finite element method

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The preparation and performance analysis of zirconium-modified aluminum phosphate-based high-temperature(RT-1500℃)resistant adhesive for joining alumina in extreme environment

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Journal of Advanced Ceramics 2024年第7期13卷 911-932页

作者： Jingxuan Liu Yange Wan Bo Xiao Jiancun Li Zhanming Hu Ruoyu Zhang Xiaoxia Hu Jiachen Liu Guoshuai Cai Hongli Liu Mingchao Wang College of Science Civil Aviation University of ChinaTianjin 300300China Department of Safety engineering Civil Aviation University of ChinaTianjin 300300China Binzhou Beicheng Construction engineering Materials Testing Co. Ltd.Binzhou 256602China Department of Aviation engineering Civil Aviation University of ChinaTianjin 300300China School of Materials and engineering Key Lab of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin UniversityTianjin 300072China

High-temperature-resistant adhesives are critical materials in the aerospace *** zirconium-modified aluminum phosphate-based adhesives developed in this work had the advantage of adjustable thermal expansibility,achieving a high matching of coefficient of thermal expansion(CTE)with *** introduction of zirconium can significantly improve the thermal stability of the adhesive matrix,and the Zr/Al ratio substantially affects the various reaction processes inside the adhesive,especially the types of zirconium-containing *** of the zirconium-containing compounds in the A7Z3 adhesive were ZrO_(2) only when the mass ratio of zirconium hydroxide to aluminum hydroxide was 3:7,which was the key reason why it had the highest *** room-temperature bonding strength of A7Z3 after heat treatment at 1500℃reached 67.2 *** pretreatment at 1500℃,the high-temperature bonding strength of A7Z3 was greater than 50 MPa in the range of(room temperature)RT-1000℃.After 40 thermal cycles between RT and 1500℃,the bonding strength still reached 10 *** bonding occurred at temperatures below 1000℃,while chemical bonding dominated above 1000℃based on the generation of Al5BO9 and mullite at the interfaces.

关键词： high-temperature-resistant adhesive thermal expansion property zirconium-modified aluminum phosphate bonding performance thermal cycling bonding mechanism

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Characteristics of office lighting energy consumption and its impact on air conditioning energy consumption

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Energy and Built Environment 2024年第4期5卷 529-543页

作者： Siao Song Jibo Long Hanyu Jiang Bin Ran Lun Yao College of civil engineering Xiangtan UniversityXiangtanHunan 411105China

The energy consumption of office buildings has increased sharply since the 21st century with the increasing ur-banization *** this stage,the energy consumption of office buildings in China mainly comes from air conditioning and *** paper obtains the regression equation of natural lighting illumination and radi-ant heat gain under different curtain conditions through experiments and simulations,and gives the theoretical calculation process of curtain regulation of office thermal and light environment and energy *** and Ecotect software were used to analyze the thermal and light environment and energy consumption of the *** results show that setting curtains in the room can effectively improve the indoor thermal light en-vironment,the higher the transmittance of curtains the lower the lighting energy consumption,the higher the number of high temperature hours of natural room temperature and the greater the radiant heat *** room with thick curtains has the lowest energy consumption for air conditioning in summer,followed by the room with thin curtains,and the room without curtains has the highest energy consumption for air *** room without curtains has the lowest energy consumption for artificial lighting,the room with thin curtains has the second lowest,and the room with thick curtains has the highest electricity consumption for artificial *** air conditioning energy consumption accounts for the main building energy consumption,followed by the lighting energy *** setting curtains in the office,the air conditioning energy consumption caused by the solar radiation heat entering the room through the exterior windows is smaller than the lighting energy consumption caused by artificial ***,the installation of internal shading with moderate trans-mittance and good thermal insulation performance can make the energy saving of lighting and air conditioning energy consumption reach the

关键词： Curtains Light environment Thermal environment Energy saving

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Focal mechanics and disaster characteristics of the 2024 M 7.6 Noto Peninsula Earthquake,Japan

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Frontiers of Structural and civil engineering 2024年第9期18卷 1378-1387页

作者： Guang-qi CHEN Yan-qiang WU Ming-yao XIA Zhi-yuan LI School of civil and Transportation engineering Hebei University of TechnologyTianjin 300131China graduate School of engineering Kyushu UniversityFukuoka 819-0395Japan The First Monitoring and Application Center China Earthquake AdministrationTianjin 300180China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China

On January 1,2024,a devastating M 7.6 earthquake struck the Noto Peninsula,Ishikawa Prefecture,Japan,resulting in significant casualties and property *** information from the first six days after the earthquake,this article analyzes the seismic source characteristics,disaster situation,and emergency response of this *** results show:1)The earthquake rupture was of the thrust type,with aftershock distribution showing a north-east-oriented belt-like feature of 150 km.2)Global Navigation Satellite System(GNSS)and Interferometric synthetic aperture radar(InSAR),observations detected significant westward to north-westward co-seismic displacement near the epicenter,with the maximum horizontal displacement reaching 1.2 m and the vertical uplift displacement reaching 4 m.A two-segment fault inversion model fits the observational data well.3)Near the epicenter,large Peak Ground Velocity(PGV)and Peak Ground Acceleration(PGA)were observed,with the maxima reaching 145 cm/s and 2681 gal,respectively,and the intensity reached the highest level 7 on the Japanese(Japan Meteorological Agency,JMA)intensity standard,which is higher than level 10 of the United States Geological Survey(USGS)Modified Mercalli Intensity(MMI)standard.4)The observation of the very rare multiple strong pulse-like ground motion(PLGM)waveform poses a topic worthy of research in the field of earthquake engineering.5)As of January 7,the earthquake had left 128 deaths and 560 injuries in Ishikawa Prefecture,with 1305 buildings completely or partially destroyed,and had triggered a chain of disasters including tsunamis,fires,slope failures,and road ***,this paper summarizes the emergency rescue,information dissemination,and other disaster response and management measures taken in response to this *** work provides a reference case for carrying out effective responses,and offers lessons for handling similar events in the future.

关键词： Noto Peninsula Earthquake earthquake rupture mechanism earthquake disaster emergency response pulse-like ground motion

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