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Regression Method for Rail Fastener Tightness Based on Center-Line Projection Distance Feature and Neural Network

Chinese Journal of Mechanical engineering 2024年第2期37卷 356-371页

作者： Yuanhang Wang Duxin Liu Sheng Guo Yifan Wu Jing Liu Wei Li Hongjie Wang Robotics Research Center School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China china construction industrial&energy engineering Group co. Ltd.Nanjing 210023China

In the railway system,fasteners have the functions of damping,maintaining the track distance,and adjusting the track ***,routine maintenance and inspection of fasteners are important to ensure the safe operation of track ***,assessment methods for fastener tightness include manual observation,aco.stic wave detection,and image *** are limitations such as low accuracy and efficiency,easy interference and misjudgment,and a lack of accurate,stable,and fast detection *** at the small deformation characteristics and large elastic change of fasteners from full loosening to full tightening,this study proposes high-precision surface-structured light technology for fastener detection and fastener deformation feature extraction based on the center-line projection distance and a fastener tightness regression method based on neural ***,the method uses a 3D camera to obtain a fastener point cloud and then segments the elastic rod area based on the iterative closest point algorithm *** co.ponent analysis is used to calculate the normal vector of the segmented elastic rod surface and extract the point on the centerline of the elastic *** point is projected onto the upper surface of the bolt to calculate the projection ***,the mapping relationship between the projection distance sequence and fastener tightness is established,and the influence of each parameter on the fastener tightness prediction is ***,by setting up a fastener detection scene in the track experimental base,co.lecting data,and co.pleting the algorithm verification,the results showed that the deviation between the fastener tightness regression value obtained after the algorithm processing and the actual measured value RMSE was 0.2196 mm,which significantly improved the effect co.pared with other tightness detection methods,and realized an effective fastener tightness regression.

关键词： Railway system Fasteners Tightness inspection Neural network regression 3D point cloud processing

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A double-layer radiative co.ling co.ting that utilizes the refractive index difference between layers to achieve extremely high solar reflectivity

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Science china Technological Sciences 2024年第10期67卷 3182-3189页

作者： WANG FuQiang LI ChunZhe YANG ZhenNing XIE WeiXin LI Xiang XU ZengHui YAN YuYing CHENG ZiMing School of energy Science and engineering Harbin Institute of Technology School of New energy Harbin Institute of Technology at Weihai china construction Eco.Environmental Protection Technology co. Ltd. Faculty of engineering University of Nottingham

Passive daytime radiative co.ling（PDRC） technology has great potential in reducing co.ling energy co.sumption. In order to further improve the spectral performance of PDRC co.tings, current researchers mostly focus on the selection and size design of functional particles, while ignoring the optical properties enhancement effect caused by the interlayer binder. In this study, based on the principle that the refractive index difference between layers enhanced the backscattering performance of the solar spectrum, we proposed and manufactured a double-layer PDRC co.ting with polyvinylidene difluoride（PVDF） as the filmforming material in the upper layer and polydimethylsiloxane（PDMS） as the film-forming material in the lower layer, both filled with Al2O3and SiO2particles. The double-layer PDRC co.ting exhibited excellent spectral performance that a high solar reflectivity of 98% and an emissivity of 0.95 at the “atmospheric window” band. In co.parison, the solar spectrum reflectivity of the single-layer PDRC co.tings based on PVDF and PDMS of the same thickness was 95% and 94.7%, respectively. Outdoor tests showed that the PDRC co.ting achieved a temperature decrease of up to 7.1℃ under direct sunlight at noon time. In addition, the PDRC co.ting had excellent weather resistance, water resistance, and other basic properties. This article opens up a new idea and provides methodological guidance for the design of double-layer PDRC co.tings.

关键词： double-layer radiative co.ling co.ting spectral modulation interlayer refractive index solar energy radiative transfer

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A new neural-network-based method for structural damage identification in single-layer reticulated shells

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Frontiers of Structural and Civil engineering 2024年第1期18卷 104-121页

作者： Jindong ZHANG Xiaonong GUO Shaohan ZONG Yujian ZHANG co.lege of Civil engineering Tongji UniversityShanghai 200092China china construction Eighth engineering Division co. Ltd.Shanghai 200135China

Single-layer reticulated shells(SLRSs)find widespread application in the roofs of crucial public structures,such as gymnasiums and exhibition *** this paper,a new neural-network-based method for structural damage identification in SLRSs is ***,a damage vector index,NDL,that is related only to the damage localization,is proposed for SLRSs,and a damage data set is co.structed from NDL *** the basis of visualization of the NDL damage data set,the structural damaged region locations are identified using co.volutional neural networks(CNNs).By cross-dividing the damaged region locations and using parallel CNNs for each regional location,the damaged region locations can be quickly and efficiently identified and the undamaged region locations can be ***,a damage vector index,DS,that is related to the damage location and damage degree,is proposed for *** on the damaged region identified previously,a fully co.nected neural network(FCNN)is co.structed to identify the location and damage degree of *** effectiveness and reliability of the proposed method are verified by co.sidering a numerical case of a spherical *** calculation results showed that the proposed method can quickly eliminate candidate locations of potential damaged region locations and precisely determine the location and damage degree of members.

关键词： single-layer reticulated shell damage identification neural network co.volutional neural network cross-partitioning method

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Numerical study of particle behaviours and heat transfer in a co.plex rotary kiln

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Particuology 2024年第9期92卷 81-94页

作者： Qingshan Jian Hailin Gu Kaige Wang Shuai Wang Mingxiu Zhan Jinqing Wang Longjie Ji Zuohe Chi Guangxue Zhang The Institute for energy engineering China Jiliang UniversityHangzhou310000China Qingshanhu energy Research Center Zhejiang UniversityHangzhou311305China State Key Laboratory of Clean energy Utilization Zhejiang UniversityHangzhou310027China Beijing construction engineering Group Environmental Remediation co. LtdBeijing100015China

Rotary kiln is widely used for thermal disposal of solid waste due to its effectiveness and high efficiency in recent *** further improve the processing efficiency,a newly designed rotary kiln with three-section structure is proposed,and the behaviours of particle motion and heat transfer are ***,a lab-scale rotary kiln is manufactured,and experiments are carried *** by experimental data,a CFD-DEM numerical model is developed to analyze the particle motion and heat transfer characteristics with the effects of inlet flue gas temperature,feeding rate and rotating *** results show that the outlet temperature increases linearly with the flue gas temperature,while it is negatively co.related with the feeding rate and rotating *** addition,the volumetric heat transfer co.fficient in this co.plex rotary kiln is analyzed,the overall heat transfer co.fficient is between 200 and 700 W/(m^(3)K).

关键词： Rotary kiln Lifter Particlemotion Heat transfer CFD-DEM

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Hydration Behavior and Cementitious Properties of Calcium Carbonate-aluminate Minerals co.posite

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 126-133页

作者：王冲周帅 ZOU Luyao LIU Jiawen ZHENG Yalin co.lege of Materials Science and engineering Chongqing UniversityChongqing 400045China china West construction Group co. Ltd.Chengdu 610015China

The purpose of this research is to investigate the hydration behavior and cementitious properties of the mixture of calcium carbonate and aluminate, and to explore whether it can be adopted as a new low-carbon cementitious material. The co.posite system of calcium carbonate and aluminate minerals is studied by measuring the co.ponent of hydration products, the hydration heat, setting time and co.pressive *** results prove that the co.posite system has certain cementitious properties and is feasible to prepare new low-carbon cement.

关键词： limestone hydrated calcium carboaluminate cementitious properties mechanical properties

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Analysis of Calcined Red Mud Properties and Related Mortar Performances

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Fluid Dynamics & Materials Processing 2024年第5期20卷 901-913页

作者： Zhengfan Lyu Yulin Li Mengmeng Fan Yan Huang Chenguang Li Technical Center Office Guangxi Jiaojian Engineering Inspection Consulting Co.Ltd.Nanning530001China Technical Center Office Guangxi Road Construction Engineering Group Co.Ltd.Nanning530001China Nanning Road construction Technology and Road construction Materials engineering Technology Research Centre Guangxi Road Construction Engineering Group Co.Ltd.Nanning530001China

Red mud(RM)is a low-activity industrial solid waste,and its utilization as a resource is currently a hot *** this study,the micro characteristics of red mud at different calcination temperatures were analyzed using X-ray diffraction and scanning electron *** performance of calcined red mud was determined through mortar strength *** indicate that high-temperature calcination can change the mineral co.position and microstructure of red mud,and increase the surface roughness and specific surface *** the optimal temperature of 700°C,the addition of calcined red mud still leads to a decrease in mortar strength,but its activity index and flexural co.fficient increase by 16.2%and 11.9%with respect to uncalcined red mud,reaching values of 0.826 and 0.974,*** with the co.trol group,the synergistic activation of calcined red mud with slag can increase the co.pressive and flexural strength of the mortar by 12.9%and 1.5%,reaching 8.7 and 62.4 MPa,***,the activity index and flexural co.fficient of the calcined RM and GGBS(Ground Granulated Blast furnace Slag)mixtures also increase to 1.015 and 1.130,respectively.

关键词： Red mud slag thermal activation synergistic activation mortar test microsco.ic properties

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Effect of the Retarder on Initial Hydration and Mechanical Properties of the"one-step"Alkaliactivated co.posite Cementitious Materials

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1199-1213页

作者： DING Rui HE Yue LI Xingchen LI Han TIAN Hao WANG Hongen School of Materials Science and engineering Jilin Jianzhu UniversityChangchun 130118China Ziyang Urban construction Investment Group co. LtdNanchong 637000China Shandong Taihe Urban construction Development co. Ltd.Jining 272000China

This paper studied the effects of different retarders on the performance of the"one-step"alkali-activated co.posite cementitious material(ACCM)which is co.posed of ground granulated blast slag(GGBS)and fly ash(FA),and analyzed its mechanical properties,hydration mechanism,and retardation *** effects of retarders on the hydration products,mechanical properties,and hydration kinetics of ACCM were investigated using XRD,SEM,FTIR,EDS,and thermoactive *** results showed that Na_(2)B_(4)O_(7)·10H_(2)O(B)delayed the exotherm during the alkali activation process and co.ld effectively delay the setting time of ACCM,but the mechanical properties were slightly *** setting time of ACCM increased with the increase in SG co.tent,but the mechanical properties of ACCM decreased with the increase in SG co.tent.C1_(2)H_(22)O_(11)(CHO)co.ld effectively delay the hydration reaction of ACCM and weakly enhanced the co.pressive strength.H_(3)PO_(4)(HP)at a co.centration of 0.05 mol/L had a certain effect on ACCM retardation,but HP at a co.centration of 0.07 and 0.09 mol/L had an effect of promoting the setting and hardening time of ACCM.

关键词： "one-step"alkali-activated co.posite cementitious materials solid activator hydration mechanism retarder retarding mechanism

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Research on an innovative structure of an open-ribbed steel-ultra-high performance co.crete co.posite bridge deck

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Frontiers of Structural and Civil engineering 2024年第5期18卷 716-730页

作者： Xudong SHAO Xuan SUN Deqiang ZOU Junhui CAO Chuanqi YANG School of Civil engineering Hunan UniversityKey Laboratory for Wind and Bridge Engineering of Hunan ProvinceChangsha 410082China china construction Fifth engineering Division co. Ltd.Changsha 410004China

To co.pletely solve the problem of fatigue cracking issue of orthotropic steel bridge decks(OSDs),the authors proposed a steel–ultra-high performance co.crete(UHPC)lightweight co.posite deck(LWCD)with closed ribs in *** on the successful application of that LWCD,an adaptation inco.porating an innovative co.posite deck structure,i.e.,the hot-rolled section steel–UHPC co.posite deck with open ribs(SSD)is proposed in this paper,aiming to simplify the fabrication process as well as to reduce the co.t of *** on a long-span cable-stayed bridge,a design scheme is proposed and is co.pared with the co.ventional OSD ***,a finite element(FE)calculation is co.ducted to reflect both the global and local behavior of the SSD scheme,and it is found that the peaked stresses in the SSD co.ponents are less than the co.responding allowable values.A static test is performed for an SSD strip specimen to understand the anti-cracking behavior of the UHPC layer under negative bending *** static test results indicate that the UHPC layer exhibited a satisfactory tensile toughness,the UHPC tensile strength obtained from the test is 1.8 times the calculated stress by the FE model of the real *** addition,the fatigue stresses of typical fatigue-prone details in the SSD are calculated and evaluated,and the influences of key design parameters on the fatigue performance of the SSD are *** to the fatigue results,the peaked stress ranges for all of the 10 fatigue-prone details are within the co.responding co.stant amplitude fatigue *** a fatigue test is carried out for another SSD strip specimen to explore the fatigue behavior of the fillet weld between the longitudinal and transverse *** specimen failed at the fillet weld after equivalent 47.5 million cycles of loading under the design fatigue stress range,indicating that the fatigue performance of the SSD co.ld meet the fatigue design *** calculations and experim

关键词： steel-ultra-high performance co.crete co.posite deck open rib strip model test static and fatigue performance orthotropic steel deck

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A theoretical model for impact protection of flexible polymer material

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 217-226页

作者： Huifeng Xi Hui Pan Song Chen Heng Xiao MOE Key Lab of Disaster Forecast and co.trol in engineering School of Machanics and Construction EngineeringJinan UniversityGuangzhou 510632China Doctor Workstation of Xuwen co.nty Guangdong Hydropower energy co. Ltd.Xuwen 524100China

The relationship between the protective performance of flexible polymer material and material parameters(elasticmodulus,visco.ity co.fficient)is explored,an impact co.lision motion equation between two bodies is establishedfrom the visco.lastic material co.stitutive,and the relationship between the kinematic response and the materialparameters is *** on the Kelvin co.stitutive model,a theoretical model for impact between the pro-tective body and the protected body is established,then the dynamic response is *** feasibility of themodel was verified by drop hammer experiment,and the material parameters(elastic modulus,visco.ity co.ffi-cient)were obtained by *** model is discretized and the relationship between local impact response andmaterial parameters is *** discussion results on the relationship between the impact response and theprotective material performance indicate that adjusting the elastic modulus,visco.ity co.fficient,and thicknessof the protective material can effectively improve protective effect.

关键词： Flexible polymer material Visco.lastic material Kelvin modelDynamic response Elastic modulus and visco.ity co.fficient

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Enhanced wear prediction of tunnel boring machine disc cutters for accurate remaining useful life estimation using a hybrid model

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Frontiers of Structural and Civil engineering 2024年第4期18卷 642-662页

作者： Xinghai ZHOU Yakun ZHANG Guofang GONG Huayong YANG Qiaosong CHEN Yuxi CHEN Zhixue SU The State Key Laboratory of Fluid Power&Mechatronic Systems Zhejiang UniversityHangzhou 310027China Guangzhou Rail Transit construction engineering co.sulting co. Ltd.Guangzhou 510000China china Railway engineering Equipment Group co. Ltd.Zhengzhou 450016China

In tunnel construction with tunnel boring machines(TBMs),accurate prediction of the remaining useful life(RUL)of disc cutters is critical for timely maintenance and replacement to avoid delays and co.t *** paper introduces a novel hybrid model,integrating fundamental and data-driven approaches,to enhance wear prediction of TBM disc cutters and enable accurate RUL *** fundamental model is improved by inco.porating co.posite wear mechanisms and load estimation techniques,showcasing superior prediction accuracy co.pared to single-mechanism ***,the hybrid model innovatively inco.porates a data-driven supplementary residual term into the improved fundamental model,leading to a high-performance wear prediction *** actual field data from a highway tunnel project in Shenzhen,the performance of the hybrid model is rigorously tested and co.pared with pure fundamental and data-driven *** hybrid model outperforms the other models,achieving the highest accuracy in predicting TBM disc cutter wear(mean absolute error(MAE)=0.53,root mean square error(RMSE)=0.64).Furthermore,this study thoroughly analyzes the hybrid model’s generalization capability,revealing significant impacts of geological co.ditions on prediction *** model’s generalization capability is also improved by expanding and updating the data *** RUL estimation results provided by the hybrid model are straightforward and effective,making it a valuable tool by which construction staff can monitor TBM disc cutters.

关键词： tunnel boring machine disc cutter wear prediction remaining useful life field data hybrid model

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