检索结果-南通市图书馆

Journal of Rock Mechanics and Geotechnical engineering 2025年第1期17卷 573-585页

作者： Xiaoyi Yuan Lei Peng Bing Chen Department of civil engineering Shanghai Jiao Tong UniversityShanghai200240China State Key Laboratory of Ocean engineering Shanghai Jiao Tong UniversityShanghai200240China

This paper investigated the use of magnesium phosphate cement (MPC) for solidifying sludge with different humic acid (HA) content (ranging from 0 to 4.5%) and explored the solidification mechanism. Fluidity, setting time, unconfined compressive strength (UCS), the strength formation mechanism, and the spontaneous imbibition process of solidified sludge (SS) were studied. The results indicate that MPC can be used as a low-alkalinity curing agent. As the HA content increases, fluidity and setting time also increase, while hydration temperature and strength decrease. Additionally, the failure mode of SS transitions from brittleness to ductility. The strength of SS is composed of the cementation strength provided by MPC hydration products, matric suction, osmotic suction, and the structural strength of the sludge. MPC reduces the structural strength caused by the shrinkage of pure sludge under the action of matric suction, but the incorporation of MPC significantly improved the strength when the sludge is eroded by water. X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that the sludge and MPC can form a dense solid body, forming various hydration products, and synergistically improve the mechanical properties of the sludge.

关键词： Sludge solidification MPC Unsaturated spontaneous imbibition Strength mechanism Humic acid

Numerical Study of Cavitating Flows around a Hydrofoil with Deep Analysis of Vorticity Effects

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2025年第1期21卷 179-204页

作者： Shande Li Wen’an Zhong Shaoxing Yu Hao Wang Xichang Satellite Launch Center Wenchang571300China College of Water Resources and civil engineering China Agricultural UniversityBeijing100083China

This paper aims to numerically explore the characteristics of unsteady cavitating flow around a NACA0015 hydrofoil,with a focus on vorticity *** simulation utilizes a homogeneous mixture model coupled with a filter-based density correction turbulence model and a modified Zwart cavitation *** study investigates the dynamic cavitation features of the thermal fluid around the hydrofoil at various incoming flow *** systematically elucidates the evolution of cavitation and vortex dynamics corresponding to each velocity *** results indicate that with increasing incoming flow velocity,distinct cavitation processes take place in the flow field.

关键词： Cavitating flow hydrofoil flow velocity vorticity Computational Fluid Dynamics(CFD)

Comparative Study on Hydrodynamic Performances of Fully Activated and Semi-Activated Oscillating Hydrofoils for Energy Harvesting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2025年第1期24卷 31-39页

作者： QU Hengliang LI Xueyan SHI Hongyuan DONG Xiaochen School of Hydraulic and civil engineering Ludong UniversityYantai 264025China Institute of Sea-Crossing engineering Ludong UniversityYantai 264025China Shandong Provincial Key Laboratory of Ocean engineering Qingdao 266100China

The oscillating hydrofoil represents a promising technology for harvesting energy from tidal *** previous research has primarily focused on oscillating hydrofoils utilizing a fully activated control strategy,the industry predominantly employs a semi-activated control strategy in existing tidal current energy *** is essential to identify the differences in predicted energy-harvesting performance between these two controlling strategies through experimental modeling or numerical ***,the suitability of the fully activated control strategy in predicting the energy-harvesting capabilities of oscillating hydrofoils is *** 2D numerical models of hydrofoil based on fully activated and semi-activated control strategies have been developed and *** amplitudes of heaving and pitching movements for the fully activated hydrofoil are determined to match those of the semi-activated *** results show that the main difference between the two control strategies lies in the phase shift occurring between the pitching and heaving *** phase shift affects the lift force and its coordination with the heaving velocity,which in turn affects the power ***,the maximum relative efficiency difference obtained between the fully activated and semi-activated control strategies can reach 191%.

关键词： oscillating hydrofoil controlling strategy comparative study energy-harvesting performance

Microstructure effect of mechanical and cracking behaviors on brittle rocks using image-based fast Fourier transform method

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical engineering 2025年第1期17卷 399-413页

作者： Mingyao Li Lei Peng Dejun Liu Jianping Zuo School of Mechanics and civil engineering China University of Mining and TechnologyBeijing100083China State Key Laboratory for Tunnel engineering China University of Mining and TechnologyBeijing100083China

The internal microstructures of rock materials, including mineral heterogeneity and intrinsic microdefects, exert a significant influence on their nonlinear mechanical and cracking behaviors. It is of great significance to accurately characterize the actual microstructures and their influence on stress and damage evolution inside the rocks. In this study, an image-based fast Fourier transform (FFT) method is developed for reconstructing the actual rock microstructures by combining it with the digital image processing (DIP) technique. A series of experimental investigations were conducted to acquire information regarding the actual microstructure and the mechanical properties. Based on these experimental evidences, the processed microstructure information, in conjunction with the proposed micromechanical model, is incorporated into the numerical calculation. The proposed image-based FFT method was firstly validated through uniaxial compression tests. Subsequently, it was employed to predict and analyze the influence of microstructure on macroscopic mechanical behaviors, local stress distribution and the internal crack evolution process in brittle rocks. The distribution of feldspar is considerably more heterogeneous and scattered than that of quartz, which results in a greater propensity for the formation of cracks in feldspar. It is observed that initial cracks and new cracks, including intragranular and boundary ones, ultimately coalesce and connect as the primary through cracks, which are predominantly distributed along the boundary of the feldspar. This phenomenon is also predicted by the proposed numerical method. The results indicate that the proposed numerical method provides an effective approach for analyzing, understanding and predicting the nonlinear mechanical and cracking behaviors of brittle rocks by taking into account the actual microstructure characteristics.

关键词： Rock microstructure Cracking process Brittle rocks Fast Fourier transform(FFT) Digital image processing(DIP)

Stability analysis of cut-fill and deep patch unsaturated slopes under steady infiltration conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2025年第1期68卷 352-363页

作者： Fei ZHANG Shilin JIA Yufeng GAO Key Laboratory of the Ministry of Education for Geomechanics and Embankment engineering College of Civil and Transportation EngineeringHohai UniversityNanjing 210098China

Cut-fill slopes,as an economical solution in mountainous road construction,are typically jeopardized by cracks and *** patch repair with geosynthetics is an effective technique to mitigate these *** paper proposes an upperbound analytical framework for evaluating the stability of cracked cut-fill slopes and deep patch slopes under one-dimensional steady *** proposed framework is employed to investigate suction-induced effects on slope stability and critical failure surface through a series of parametric *** findings indicate that the suction-induced effect generally increases with air-entry pressure and approaches a constant *** stability of a cracked cut-fill slope can be enhanced by deep patch repair with *** the deep patch depth enhances local stability and reduces the required reinforcement ***,the depth of the deep patch should be greater than the crack depth to avoid local ***,a design method involving both local and global stability for deep patch slopes is presented,along with a design example for illustration.

关键词： slope stability limit analysis unsaturated soil geosynthetic-reinforced slope cut-fill slope deep patch

A Review of Infrared Thermography Applications for civil Infrastructure

在线全文

学校读者我要写书评

暂无评论

Structural Durability & Health Monitoring 2025年第2期19卷 193-231页

作者： Prabal Shrestha Onur Avci Sahabeddin Rifai Feras Abla Michael Seek Karl Barth Udaya Halabe Department of civil and Environmental engineering West Virginia UniversityMorgantownWV 26506USA Department of engineering Technology Old Dominion UniversityNorfolkVA 23529USA School of Sustainable engineering and the Built Environment Arizona State UniversityTempeAZ 85287USA

civil infrastructure is continuously subject to aging and deterioration due to multiple factors,which lead to a decline in performance and impact structural *** damage on structures increases operational costs and poses significant risks to public *** maintenance,repair,and rehabilitation strategies are needed to ensure civil infrastructure’s overall safety and ***-Destructive Evaluation(NDE)methods are utilized to assess latent damage and provide decision-makers with real-time information for mitigating *** the last decade,there has been a significant increase in the research and development of innovative NDE techniques to improve data processing and promote efficient and accurate infrastructure *** paper aims to review one of those methods,namely,Infrared Thermography(IRT),and its applications in civil infrastructure.A comprehensive review is presented by investigating numerous journal articles,research papers,and technical reports describing numerous IRT applications for bridges,buildings,and general civil structures made from different *** capability of IRT to identify and pinpoint anomalies,typically in the early stages of degradation,has excellent potential to improve the safety and shore up the dependability of civil infrastructures while reducing expenses tied to maintenance and ***,the non-invasive nature of IRT is beneficial in mitigating disturbances and downtime that may occur during various inspection *** is highlighted that IRT is a highly versatile and effective tool for infrastructure condition *** further advancement and fine-tuning of the available techniques,it is likely that IRT will continue to gain significant popularity in maintaining and monitoring civil infrastructure.

关键词： Infrared thermography(IRT) civil infrastructure non-destructive evaluation(NDE)

Experimental Research on a Feasible Building Insulation Material Based Reed in China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2025年第1期34卷 176-187页

作者： LIU Tiantian PENG Yizhe LIU Lifang CAI Chenghan WANG Shuang LI Hongqiang College of civil engineering Hunan UniversityChangsha 410082China College of civil engineering Hunan University of Science and TechnologyXiangtan 411201China School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212100China National Center for International Research Collaboration in Building Safety and Environment(NCIRCBSE) Hunan UniversityChangsha 410082China Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education Hunan UniversityChangsha 410082China

The seemingly useless reeds are prepared as thermal insulation materials,which not only meet the requirements of environmental sustainability but also enhance the added value of reeds,creating new economic *** hydrophobicity of raw biomass surfaces leads to problems such as weak bonding strength and non-dense structure in the formed materials,as well as issues related to the residual insect infestations on the *** this study,reed straw was used as the raw material,and foamed geopolymer was used as the binder to prepare building insulation materials based *** improve the interfacial adhesion performance between reed straw and foamed geopolymer,a thermochemical modification method-thermal carbonization,was *** this study,the mechanical properties and hydraulic properties of the studied materials with different degrees of surface thermal modification were tested,especially the fire resistance performance,and weathering resistance performance rarely found in published *** the surface thermal modification condition of reed straw was 250℃(30 min),the comprehensive performance of reed-based building insulation materials was the best,when the studied material density was 321.3 kg/m^(3);the compressive strength was 0.59 MPa;the thermal conductivity was 0.101 W/(m·K);the pH was 11.27;the moisture absorption rate was 25.1%,and the compressive strength loss rate in wet-dry cycles was 18.5%.In addition,it had excellent fire resistance performance and weathering resistance *** new material can be widely used to improve the thermal insulation of traditional buildings and as sandwich filler in prefabricated buildings,such as preparing insulating walls.

关键词： pre-treatment of reeds interface adhesion properties building insulation material based reed fire resistance performance weathering resistance performance

Nano-Enhanced Dairy Scum Biodiesel Blends:Unleashing the Power of Aluminium Oxide for Sustainable and Efficient Engine Performance

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2025年第1期34卷 283-302页

作者： Veeranna MODI Prasad B.RAMPURE Sunil Kumar SHETTY Madeva NAGARAL Channa Keshava NAIK N Johar MGM Muhammad Irsyad ABDULLAH Abdullah I.AL-MANSOUR Shamshad ALAM KLE College of engineering and Technology ChikodiVisvesvaraya Technological UniversityBelagavi 590018KarnatakaIndia Nitte(Deemed to be University) NMAM Institute of Technology(NMAMIT)Department of Mechanical EngineeringNitte 574110India Aircraft Research and Design Centre HALBangalore 560037KarnatakaIndia Department of Mechanical engineering BGS College of Engineering and TechnologyBengaluruAffiliated to Visvesvaraya Technological UniversityBelagaviIndia Management and Science University Selangor Darul EhsanMalaysia Department of civil engineering College of EngineeringKing Saud UniversityRiyadh-11421Saudi Arabia

This study investigates the effect of aluminium oxide nanoparticlesaddition to biodiesel blends made from dairy milk scum on performance and combustion characteristics of the diesel *** dispersion of Al_(2)O_(3)nanoparticles in B20 blends at different concentrations was done with the help of *** number of blends were prepared for the *** Machine learning algorithms(Random Forest(RF)and CatBoost)was used for the *** results show that in comparison to biodiesel blends without nanoparticles,the kinematic viscosity and density is higher for fuel blends with *** these Fuel blends have higher calorific *** blends exhibited reduced Brake Specific Fuel Consumption(BSFC)of 2.85% than the blends without nano particles(Dairy Scum Methyl Ester Biodiesel 20%+Neat Diesel 80%(in volume),DSMEB20),57.14%less CO,40.8% less hydrocarbon,and increased NO_(x)emissions compared to conventional diesel,contributing to the development of environmentally friendly and renewable biofuel blends with *** B20NP30 is the optimal blend for performance and emission *** study concludes with findings on enhanced Brake Thermal Efficiency(BTE)of 26.29% in 3×10^(-5)(in volume)Al_(2)O_(3)nanoparticle-blended DSME B20 and other DSME B20 fuel blends,emphasizing the importance of optimal nanoparticle *** correlation matrix shows how engine load,efficiency measures(BTE,BSFC),and emissions(CO,CO_(2),NO_(x),Smoke)are connected in complex *** results help us understand the complicated dynamics of engine performance and emission characteristics ***'s diagram for BTE and BSFC shows that CatBoost-based BTE models perform superior to RF-based models during the training as well as testing *** results were obtained for CO and CO_(2)emission results.

关键词： Dairy Scum Methyl Ester Biodiesel CI engine Al_(2)O_(3)concentration

Prediction of Shear Bond Strength of Asphalt Concrete Pavement Using Machine Learning Models and Grid Search Optimization Technique

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in engineering & Sciences 2025年第1期142卷 691-712页

作者： Quynh-Anh Thi Bui Dam Duc Nguyen Hiep Van Le Indra Prakash Binh Thai Pham civil engineering Department University of Transport Technology54 Trieu KhucThanh XuanHanoi100000Vietnam DDG(R)Geological Survey of India Gandhinagar382010India

Determination of Shear Bond strength(SBS)at interlayer of double-layer asphalt concrete is crucial in flexible pavement *** study used three Machine Learning(ML)models,including K-Nearest Neighbors(KNN),Extra Trees(ET),and Light Gradient Boosting Machine(LGBM),to predict SBS based on easily determinable input ***,the Grid Search technique was employed for hyper-parameter tuning of the ML models,and cross-validation and learning curve analysis were used for training the *** models were built on a database of 240 experimental results and three input variables:temperature,normal pressure,and tack coat *** validation was performed using three statistical criteria:the coefficient of determination(R2),the Root Mean Square Error(RMSE),and the mean absolute error(MAE).Additionally,SHAP analysis was also used to validate the importance of the input variables in the prediction of the *** show that these models accurately predict SBS,with LGBM providing outstanding ***(Shapley Additive explanation)analysis for LGBM indicates that temperature is the most influential factor on ***,the proposed ML models can quickly and accurately predict SBS between two layers of asphalt concrete,serving practical applications in flexible pavement structure design.

关键词： Shear bond asphalt pavement grid search optimization machine learning

Analytical solution for the fracture problem in superconducting tapes with oblique cracks under the electromagnetic force

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2025年第3期46卷 485-500页

作者： Jinjian XIE Zhaoxia ZHANG Pengpeng SHI Xiaofan GOU College of Mechanics and engineering Science Hohai University Faculty of civil engineering and Mechanics Jiangsu University School of Mathematics and Statistics Ningxia University

The fracture behavior of superconducting tapes with central and edge oblique cracks subject to electromagnetic forces is investigated. Maxwell's equations and the critical state-Bean model are used to analytically determine the magnetic flux density and electromagnetic force distributions in superconducting tapes containing central and edge oblique cracks. The distributed dislocation technique(DDT) transforms the mixed boundary value problem into a Cauchy singular integral equation, which is then solved by the Gauss-Chebyshev quadrature method to determine the stress intensity factors(SIFs).The model's accuracy is validated by comparing the calculated electromagnetic force distribution for the edge oblique crack and the SIFs for both crack types with the existing results. The findings indicate that the current and electromagnetic forces are significantly affected by the crack length and oblique angle. Specifically, for central oblique cracks, a smaller oblique angle enhances the risk of crack propagation, and a higher initial magnetization intensity poses greater danger under field cooling(FC) excitation. In contrast, for edge oblique cracks, a larger angle increases the likelihood of tape fractures. This study provides important insights into the fracture behavior and mechanical failure mechanisms of superconducting tapes with oblique cracks.

关键词： Superconducting tapes