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A six-variable quasi-3D isogeometric approach for free vibration of functionally graded graphene origami-enabled auxetic metamaterial plates submerged in a fluid medium

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 157-176页

作者： Wei CHEN Zhihong TANG Yufen LIAO Linxin PENG College of civil engineering University of South China College of civil engineering and Architecture Guangxi University key laboratory of disaster Prevention and Structural Safety of Ministry of Education Guangxi University

This paper presents, for the first time, an effective numerical approach based on the isogeometric analysis(IGA) and the six-variable quasi-three dimensional(3D)higher-order shear deformation theory(HSDT) to study the free vibration characteristics of functionally-graded(FG) graphene origami(GOri)-enabled auxetic metamaterial(GOEAM) plates submerged in a fluid medium. The plate theory incorporates the thickness stretching and the effects of transverse shear deformation without using any shear correction factors. The velocity potential function and Bernoulli's equation are used to derive the hydrodynamic pressure acting on the plate surface. Both horizontally and vertically immersed plate configurations are considered here in the form of inertia *** plates are composed of multilayer GOEAMs, with the GOri content varying through the plate's thickness in a layer-wise manner. This design results in graded auxetic *** material properties are evaluated by mixing rules and a genetic programming(GP)-assisted micromechanical model. The governing equations of motion for the FG-GOEAM plates immersed in a fluid medium are derived by Hamilton's principle. After validating the convergence and accuracy of the present model, a comprehensive parametric study is carried out to examine the effects of the GOri content, GOri distribution pattern, GOri folding degree, fluid level, immersed depth, and geometric parameter on the natural frequencies of the FG-GOEAM plates. The results show that the natural frequencies for the four GOri distribution patterns increase with the increase in the layer number when the lay number is fewer than 10, and then stabilize after the layer number reaches ***, in general, the natural frequency of the FG-GOEAM plate in a vacuum or fluid increases when the GOri content increases, while decreases when the GOri folding degree increases. Some additional findings related to the numerical results are presented in the conclusions. It is belie

关键词： free vibration functionally-graded (FG) graphene origami (GOri)-enabled auxetic metamaterial (GOEAM) plate hydrodynamic pressure isogeometric analysis (IGA) O321 quasi-three dimensional (3D) higher-order shear deformation theory (HSDT)

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Fatigue properties and constitutive model of Jintan salt rock subjected to complex cyclic loading

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International Journal of Mining Science and Technology 2025年第1期35卷 121-133页

作者： Qingchuan He Jianfeng Liu Fei Wu Cunbao Li Jie Chen Renbo Gao Chunfeng Ye Shijie Zhu state key laboratory of Coal Mine disaster Dynamics and Control Chongqing UniversityChongqing 400044China state key laboratory of Hydraulics and Mountain River engineering Sichuan UniversityChengdu 610065China state key laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground engineering College of Civil and Transportation EngineeringShenzhen UniversityShenzhen 518060China state key laboratory of Geomechanics and Geotechnical engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China

Salt cavern energy storage technology contributes to energy reserves and renewable energy *** study focuses on salt cavern gas storage in Jintan to assess the long-term stability of its surrounding rock under frequent *** fatigue test results indicate that stress holding significantly reduces fatigue life,with the magnitude of stress level outweighing the duration of holding time in determining peak *** a machine learning approach,the impact of various factors on fatigue life and peak strain was quantified,revealing that higher stress limits and stress holding adversely impact the fatigue index,whereas lower stress limits and rate exhibit a positive effect.A novel fatigue-creep composite damage constitutive model is constructed,which is able to consider stress magnitude,rate,and stress *** model,validated through multi-path tests,accurately captures the elasto-viscous behavior of salt rock during loading,unloading,and stress *** analysis further reveals the time-and stress-dependent behavior of model parameters,clarifying that strain changes stem not only from stress variations but are also influenced by alterations in elasto-viscous *** study provides a new method for the mechanical assessment of salt cavern gas storage surrounding rocks.

关键词： Salt cavern gas storage Cyclic loading Fatigue characteristics Constitutive model

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Sulfur doping and oxygen vacancy in In2O3 nanotube co-regulate intermediates of CO2 electroreduction for efficient HCOOH production and rechargeable Zn-CO2 battery

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Journal of Energy Chemistry 2025年第2期101卷 474-484页

作者： Yu Li Zhengrong Xu Quanxin Guo Qin Li Rui Liu key laboratory of Advanced civil engineering Materials of Ministry of Education School of Materials Science and Engineering Tongji University

By manipulating the distribution of surface electrons,defect engineering enables effective control over the adsorption energy between adsorbates and active sites in the CO2reduction reaction（CO2RR）.Herein,we report a hollow indium oxide nanotube containing both oxygen vacancy and sulfur doping（V_o-Sx-In2O3） for improved CO2-to-HCOOH electroreduction and *** componential synergy significantly reduces the*OCHO formation barrier to expedite protonation process and creates a favorable electronic micro-environment for*HCOOH *** a result,the CO2RR performance of Vo-Sx-In2O3outperforms Pure-In2O3and V_o-In2O3,where V_o-S53-In2O3exhibits a maximal HCOOH Faradaic efficiency of 92.4% at-1,2 V *** hydrogen electrode（RHE） in H-cell and above 92%over a wide window potential with high current density(119.1 mA cm-2at-1.1 V ***) in flow ***,the rechargeable Zn-CO2battery utilizing V_o-S53-In2O3as cathode shows a high power density of 2.29 mW cm-2and a long-term stability during charge-discharge *** work provides a valuable perspective to elucidate co-defective catalysts in regulating the intermediates for efficient CO2RR.

关键词： CO2 electroreduction In2O3 Intermediate Oxygen vacancy Sulfur doping Zn-CO2 battery

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Dynamic properties of low-density expandable polystyrene concrete materials

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Defence Technology(防务技术) 2025年第1期43卷 94-108页

作者： Jue Han Hualin Fan Army engineering University of PLA Nanjing 210007China Research Center of Lightweight Structures and Intelligent Manufacturing State Key Laboratory of Mechanics and Control of Aerospace StructuresNanjing University of Aeronautics and AstronauticsNanjing 210016China Henan International Joint laboratory of Dynamics of Impact and disaster of engineering Structures Department of Civil EngineeringNanyang Institute of TechnologyNanyang 473004China

Expanded polystyrene(EPS)concrete,known for its environmental friendliness,energy absorption capacity,and low impedance,has significant potential application in the fields of wave absorption and vibration *** study designed and prepared EPS concrete materials with four levels of ***-static uniaxial compression and Split Hopkinson Pressure Bar(SHPB)impact tests were conducted to obtain stress-strain curves,elastic moduli,failure modes,energy absorptions,and strain rate effects of the EPS concrete under quasi-static and dynamic loading *** influences of density on various performance indicators were *** combining the Zhu-Wang-Tang(ZWT)constitutive model with a modified elastic-brittle model,a modified dynamic constitutive model was *** accuracy of the model was validated by the experimental *** results indicate that the addition of EPS particles enhances the ductility of the EPS *** EPS concrete has significant strain rate effect,which gets stronger as density *** modifiedconstitutive model accurately characterizes the dynamic stress-strain curves of the EPS concrete.

关键词： EPS concrete Impact behavior Constitutive model SHPB test

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Control of Corner Separation for a Linear Compressor Cascade via Bionic Slanting Riblets at the Endwall

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Journal of Thermal Science 2025年第1期34卷 129-144页

作者： ZHANG Peng LI Yonghong CHENG Rixin key laboratory of civil Aircraft Airworthiness Technology Civil Aviation University of ChinaTianjin 300300China College of Aeronautical engineering Civil Aviation University of ChinaTianjin 300300China

A new passive control approach,utilizing bionic slanting riblets,is employed to mitigate the flow close to the blade endwall in a linear cascade,and its effectiveness and mechanism in controlling corner separation are investigated through numerical *** slanting riblets are positioned at the endwall upstream of the cascade channel,and the influence of riblet height,yaw angle and relative position on the control of corner separation is *** findings indicate that the application of slanting riblets can efficiently counteract corner separation across the stable operational ***,the introduction of riblets with a height of merely 0.1 times the boundary layer thickness results in a significant reduction in total pressure loss by up to 14.53%,while simultaneously enhancing the static pressure coefficient by 21.74%.Flow analysis reveals that minute vortices produced within the riblet channels tend to coalesce,forming a potent large-scale vortex near the boundary layer's base *** phenomenon results in reduced additional losses compared to conventional vortex ***,the induced vortex promotes enhanced mixing between the mainstream flow and boundary layer,inhibiting the lateral displacement of low-energy fluids within the endwall boundary ***,this delays the onset of separation vortex formation and eliminates vortex rings in the corner region,ultimately enhancing the aerodynamic efficiency of the cascade.

关键词： corner separation compressor cascade slanting riblets additional losses vortex generator

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Influence of material characteristics on the failure mode and process of landslide dam

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Journal of Mountain Science 2025年第1期22卷 89-109页

作者： HU Liang ZHONG Qiming CHEN Liang YANG Meng ZHANG Lucheng WU Hao College of civil and Transportation engineering Hohai UniversityNanjing 210098China Department of Geotechnical engineering Nanjing Hydraulic Research Institute National key laboratory of Water disaster Prevention Nanjing 210098China key laboratory of Reservoir and Dam Safety of the Ministry of Water Resources Nanjing 210029China

Landslide dams,as frequent natural hazards,pose significant risks to human lives,property,and ecological *** grading characteristics and density of dam materials play a crucial role in determining the stability of landslide dams and the potential for dam *** explore the failure mechanisms and evolutionary processes of landslide dams with varying soil properties,this study conducted a series of flume experiments,considering different grain compositions and material *** results demonstrated that grading characteristics significantly influence landslide dam stability,affecting failure patterns,breach processes,and final breach ***-graded materials exhibited a sequence of surface erosion,head-cut erosion,and subsequent surface erosion during the breach process,while well-graded materials typically experienced head-cut erosion followed by surface *** coarse-graded dams,the high permeability of coarse particles allowed the dam to remain stable,as inflows matched *** dam breach model experiments also showed that increasing material density effectively delayed the breach and reduced peak breach flow ***,higher fine particle content led to a reduction in the residual dam height and the base slope of the final breach profile,although the relationship between peak breach discharge and the content of fine and coarse particles was *** better understand breach morphology evolution under different soil characteristics and hydraulic conditions,three key points were identified—erosion point,control point,and scouring *** study,by examining the evolution of failure patterns,breach processes,and breach flow discharges under various grading and density conditions,offers valuable insights into the mechanisms behind landslide dam failures.

关键词： Landslide dams Overtopping Grain size distribution Breaching process Outflow discharge

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Source Characteristics and Induced Hazards of the 2025 M6.8 Dingri Earthquake,Xizang,China,Revealed by Imaging Geodesy

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Journal of Earth Science 2025年

作者： Chen Yu Zhenhong Li Xiaoning Hu Chuang Song Suju Li Haihui Liu Jie Li Bingquan Han Zhenjiang Liu Ming Liu Shuang Zhu Xiaoye Hao Zhiyuan Li Jianbing Peng College of Geological engineering and Geomatics Chang'an University key laboratory of Loess key laboratory of Western China ' s Mineral Resources and Geological engineering Ministry of Education Big Data Center for Geosciences and Satellites Chang'an University National disaster reduction Center of China

0 INTRODUCTION According to the China Earthquake N ' etworks Center, an Mw 7.1 earthquake struck Dingri County, Tibet Autonomous Region, China, on 7 January 2025 at 9: 05 a.m. local time. The epicenter is located at 28.5°N, 87.45°E, with a depth of ～10 km. The maximum intensity reaches IX degrees, and the seismogenic fault is situated west of the nearly north-south-oriented Shenzha-Dingjie normal fault system(Figure 1a).

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Identification of failure behaviors of underground structures under dynamic loading using machine learning

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Journal of Rock Mechanics and Geotechnical engineering 2025年第1期17卷 414-431页

作者： Chun Zhu Yingze Xu Manchao He Yujing Jiang Murat Karakus Lihua Hu Yalong Jiang Fuqiang Ren School of Earth Sciences and engineering Hohai UniversityNanjing210098China state key laboratory of Coal Mine disaster Dynamics and Control Chongqing UniversityChongqing400044China state key laboratory for Geomechanics&Deep Underground engineering Xuzhou221116China Graduate School of engineering Nagasaki UniversityBunkyoNagasaki852-8521Japan School of civil Environmental and Mining EngineeringThe University of AdelaideAdelaide5005SAAustralia state key laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong UniversityNanchang330013China School of civil engineering University of Science and Technology LiaoningAnshan114051China

Understanding the dynamic responses of hard rocks is crucial during deep mining and tunneling activities and when constructing nuclear waste repositories. However, the response of deep massive rocks with openings of different shapes and orientations to dynamic loading is not well understood. Therefore, this study investigates the dynamic responses of hard rocks of deep underground excavation activities. Split Hopkins Pressure Bar (SHPB) tests on granite with holes of different shapes (rectangle, circle, vertical ellipse (elliptical short (ES) axis parallel to the impact load direction), and horizontal ellipse (elliptical long (EL) axis parallel to the impact load direction)) were carried out. The influence of hole shape and location on the dynamic responses was analyzed to reveal the rocks' dynamic strengths and cracking characteristics. We used the ResNet18 (convolutional neural network-based) network to recognize crack types using high-speed photographs. Moreover, a prediction model for the stress-strain response of rocks with different openings was established using Deep Neural Network (DNN). The results show that the dynamic strengths of the granite with EL and ES holes are the highest and lowest, respectively. The strength-weakening coefficient decreases first and then increases with an increase of thickness-span ratio (h/L). The weakening of the granite with ES holes is the most obvious. The ResNet18 network can improve the analyzing efficiency of the cracking mechanism, and the trained model's recognition accuracy reaches 99%. Finally, the dynamic stress-strain prediction model can predict the complete stress-strain curve well, with an accuracy above 85%.

关键词： Dynamic mechanical response Cracking mode Hole shape/location effect Deep Neural Network(DNN) Stress-strain prediction

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Impact fracturing of rock-like material using carbon dioxide under different temperatures and pressures

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Journal of Rock Mechanics and Geotechnical engineering 2025年第1期17卷 370-384页

作者： Shaobin Hu Zhengyong Yan Chun Zhu Manchao He Shuogang Pang College of civil and Transportation engineering Hohai UniversityNanjing210098China key laboratory of Ministry of Education for Geomechanics and Embankment engineering Hohai UniversityNanjing210098China School of Earth Sciences and engineering Hohai UniversityNanjing210098China National key laboratory for disaster Prevention Controland Intelligent Construction and Maintenance of Tunnel EngineeringChina University of Mining and Technology(Beijing)Beijing100083China School of Mechanics and civil engineering China University of Mining and TechnologyBeijing100083China

Unconventional resources (oil, gas, and geothermal) are often buried deep underground within dense rock strata and complex geological structures, making it increasingly difficult to create volumetric fractures through conventional hydraulic fracturing. This paper introduces a novel method of supercritical energetic fluid thermal shock fracturing. It pioneers a CO_(2) deflagration impact triaxial pneumatic fracturing experimental system, using high-strength similar materials to simulate deep, hard rock masses. The study investigates the rock-breaking process and crack propagation patterns under supercritical CO_(2) thermal shock, revealing and discussing the types of thermal shock-induced fractures, their formation conditions, and discrimination criteria. The research indicates that higher supercritical CO_(2) thermal shock pressures and faster pressure release rates facilitate the formation of radial branching fractures, circumferential cracks, and branch cracks. Typically, CO_(2) thermal shock generates 3–5 radial main cracks, which is significantly more than the single main crack formed by hydraulic fracturing. The formation of branched cracks is often caused by compression-shear failure and occurs under relatively harsh conditions, determined by the confining pressure, rock properties, peak thermal shock pressure, and the pressure sustained post-decompression. The findings are expected to offer a safe, efficient, and controllable shockwave method of supercritical fluid thermal shock fracturing for the exploitation of deep unconventional oil and gas resources.

关键词： Cracking mechanism Supercritical CO_(2) True triaxial experimental Impact fracturing

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Experimental investigation on the anti-detonation performance of composite structure containing foam geopolymer backfill material

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Defence Technology(防务技术) 2025年第1期43卷 304-318页

作者： Hang Zhou Hujun Li Zhen Wang Dongming Yan Wenxin Wang Guokai Zhang Zirui Cheng Song Sun Mingyang Wang School of Mechanical engineering Nanjing University of Science and TechnologyNanjing 210094China College of civil engineering and Architecture Zhejiang UniversityHangzhou 310058China Institute for Composites Science Innovation School of Materials Science and EngineeringZhejiang UniversityHangzhou310027China School of Safety Science and engineering(School of Emergency Management) Nanjing University of Science and TechnologyNanjing 210094China state key laboratory of disaster Prevention and Mitigation of Explosion and Impact Army Engineering University of PLANanjing 210014China

The compression and energy absorption properties of foam geopolymers increase stress wave attenuation under explosion impacts,reducing the vibration effect on the *** tests were conducted using several composite structure models,including a concrete lining structure(CLS)without foam geopolymer and six foam geopolymer composite structures(FGCS)with different backfill parameters,to study the dynamic response and wave dissipation mechanisms of FGCS under explosive ***,strain,and vibration responses at different locations were synchronously *** damage modes and dynamic responses of different models were compared,and how wave elimination and energy absorption efficiencies were affected by foam geopolymer backfill parameters was *** results showed that the foam geopolymer absorbed and dissipated the impact energy through continuous compressive deformation under high strain rates and dynamic loading,reducing the strain in the liner structure by 52%and increasing the pressure attenuation rate by 28%.Additionally,the foam geopolymer backfill reduced structural vibration and liner deformation,with the FGCS structure showing 35%less displacement and 70%less acceleration compared to the *** FGCS model with thicker,less dense foam geopolymer backfill,having more pores and higher porosity,demonstrated better compression and energy absorption under dynamic impact,increasing stress wave attenuation *** analyzing the stress wave propagation and the compression characteristics of the porous medium,it was concluded that the stress transfer ratio of FGCS-ρ-579 was 77%lower than that of CLS,and the transmitted wave energy was 90%*** results of this study provide a scientific basis for optimizing underground composite structure interlayer parameters.

关键词： Explosion load Composite structure Geopolymer foam Energy absorption

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