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A real-time multi-head mixed attention mechanism-based prediction method for tunnel boring machine disc cutter wear

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Science China(Technological Sciences) 2025年第1期68卷 286-307页

作者： Haodi WANG Chengjin QIN Honggan YU Zhinan ZHANG Guoqiang HUANG Zhengyang LIU Chengliang LIU State key laboratory of mechanical System and vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

In the process of hard rock tunnel excavation,workers often need to enter the tunnel boring machine(TBM)cutterhead at regular intervals to measure cutter ***,this method is time-consuming and *** cutter prediction models primarily rely on geological parameters to predict overall cutter wear before construction,making it challenging to monitor real-time wear at different locations of the cutter and obtain accurate geological *** address these challenges,this paper proposes a multi-head mixed attention mechanism-based method for real-time wear prediction of TBM disc ***,a method of cutter wear normalization to eliminate measurement noise is ***,considering the complex correlation of TBM operating parameters in feature and time dimensions,a new multi-head mixed attention mechanism model is designed to establish the dependency between different features and different moments,to better establish the mapping model between operating parameters and cutter ***,the current cutter wear state can be calculated by accumulating the wear amount of all previous small excavation *** effectiveness of the method is verified by using field data from the Mumbai *** results demonstrate that the method is capable of real-time prediction of front cutter and edge cutter wear on the test set,achieving an average accuracy rate of 95.75%.Moreover,the method can update the cutter wear status after every meter of excavation,which has good real-time *** addition,the average accuracy of cutter wear prediction of the proposed method is 11.75%,10.375%,3.875%,3.625%,1.375%,3.125%,2.25%,and 0.75%higher than that of LSTM,CNN,LSTM-CNN,CACNN,SACNN,MMADNN,MTACNN,and *** summary,this approach offers an accurate prediction of cutter wear state while reducing inspection time and costs and has high application value.

关键词： tunnel boring machine cutter wear estimation multi-head mixed attention mechanism real time

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Atomic-scale insights into microscopic mechanisms of grain boundary segregation in Al−Cu alloys

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Transactions of Nonferrous Metals Society of China 2025年第1期35卷 1-12页

作者： Xiong SHUAI Hong MAO Sai TANG Yi KONG Yong DU State key laboratory of Powder Metallurgy Central South UniversityChangsha 410083China College of mechanical Engineering Hunan Institute of Science and TechnologyYueyang 414006China National key laboratory of Science and Technology on High-strength structural Materials Central South UniversityChangsha 410083China

This study aims to clarify the mechanisms for the grain boundary(GB)segregation through investigating the absorption of excess solute atoms at GBs in Al−Cu alloys by using the hybrid molecular dynamics/Monte Carlo *** segregation mechanisms,substitutional and interstitial mechanisms,are *** intergranular defects,including dislocations,steps and vacancies,and the intervals in structural units are conductive to the prevalence of interstitial *** substitutional mechanism is favored by the highly ordered twin ***,the two mechanisms affect the GB structure *** is quantified that interstitial mechanism is less destructive to GB structure than substitutional one,and often leads to a segregation level being up to about 6 times higher than the *** findings contribute to atomic scale insights into the microscopic mechanisms about how solute atoms are absorbed by GB structures,and clarify the correlation among intergranular structures,segregation mechanisms and kinetics.

关键词： grain boundaries segregation Al−Cu alloy intergranular structure molecular dynamics simulation Monte Carlo simulation

Automatic and Rapid Throughflow-Based Optimal Design Method for Multi-Stage Axial-Flow Compressors

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Journal of Thermal Science 2025年第1期34卷 77-91页

作者： LEI Fan ZHANG Xiawen JU Yaping ZHANG Chuhua Department of Fluid Machinery and Engineering School of Energy and Power EngineeringXi'an Jiaotong UniversityXi'an 710049China State key laboratory for strength and vibration of mechanical Structures Xi'an Jiaotong UniversityXi'an 710049China Production and Environmental Department China Huaneng Group.Co.Ltd.Beijing 100031China

Throughflow design has the advantages of less time consumption and large optimization space,and thus is the corner stone of advanced design system of multi-stage axial-flow *** majority of relevant studies were limited to the throughflow inverse designs,and quite few works have been till now devoted to the throughflow optimal *** this work,an automatic and rapid throughflow-based optimal design method is proposed for axial-flow compressors in which a throughflow inverse design solver is embedded in optimal genetic algorithm to improve the design efficiency of axial-flow *** types of design parameters in the throughflow inverse design of axial-flow compressors,i.e.,swirl and shroud curve,are simultaneously used to optimize both the blade shape and flow *** proposed method is validated by the redesign optimization of the benchmark axial-flow compressor NASA Stage 35,and the CFD predictions show that the throughflow-based optimization leads to 1.18% efficiency benefit at design *** proposed method is then utilized to the two-dimensional throughflow optimal design of a large-scale 6.5-stage axial-flow industrial *** optimal design results are confirmed by CFD predictions,indicating that the proposed method can effectively improve the design adiabatic efficiency of the compressors by 1.09% within a few minutes on desk-top *** throughflow design implications are also obtained for advanced axial-flow industrial *** work could enhance the capability of throughflow design method and has engineering application value to explore the throughflow optimization space of multi-stage axial-flow compressors.

关键词： multi-stage axial-flow compressor throughflow design empirical correlations genetic algorithm aerodynamic optimization

La-substituted W-type barium-nickel ferrites for tunable and high-performance electromagnetic wave absorption

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International Journal of Minerals,Metallurgy and Materials 2025年第3期32卷 645-656页

作者： Long Wang Jiurong Liu Shenghui Xie Yanli Deng Zhou Wang Shanyue Hou Shengying Yue Gang Wang Na Wu Zhihui Zeng key laboratory for Liquid-Solid structural Evolution and Processing of Materials(Ministry of Education) School of Materials Science and EngineeringShandong UniversityJinan 250061China Electronic Materials Research laboratory Key Laboratory of the Ministry of Education and International Center for Dielectric ResearchSchool of Electronic Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Army Engineering University of PLA College of Field Engineering Nanjing 210007China laboratory for Multiscale Mechanics and Medical Science State Key Laboratory for Strength and Vibration of Mechanical StructuresSchool of AerospaceXi’an Jiaotong UniversityXi’an 710049China Department of Electrical and Computer Engineering Beckman Institute for Advanced Science and TechnologyUniversity of Illinois at Urbana-ChampaignUrbana 61801USA School of Chemistry and Chemical Engineering Shandong UniversityJinan 250100China

W-type barium-nickel ferrite(BaNi_(2)Fe_(16)O_(27))is a highly promising material for electromagnetic wave(EMW)absorption be-cause of its magnetic loss capability for EMW,low cost,large-scale production potential,high-temperature resistance,and excellent chemical ***,the poor dielectric loss of magnetic ferrites hampers their utilization,hindering enhancement in their EMW-absorption *** efficient strategies that improve the EMW-absorption performance of ferrite is highly desired but re-mains ***,an efficient strategy substituting Ba^(2+)with rare earth La^(3+)in W-type ferrite was proposed for the preparation of novel La-substituted ferrites(Ba_(1-x)LaxNi_(2)Fe_(15.4)O_(27)).The influences of La^(3+)substitution on ferrites’EMW-absorption performance and the dissipative mechanism toward EMW were systematically explored and ***^(3+)efficiently induced lattice defects,enhanced defect-induced polarization,and slightly reduced the ferrites’bandgap,enhancing the dielectric properties of the ***^(3+)also enhanced the ferromagnetic resonance loss and strengthened magnetic *** effects considerably improved the EMW-absorption perform-ance of Ba_(1-x)LaxNi_(2)Fe_(15.4)O_(27)compared with pure W-type *** x=0.2,the best EMW-absorption performance was achieved with a minimum reflection loss of-55.6 dB and effective absorption bandwidth(EAB)of 3.44 GHz.

关键词： electromagnetic wave absorption W-type barium ferrite rare earth dielectric

Dynamic modeling of a three-dimensional braided composite thin plate considering braiding directions

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 123-138页

作者： Chentong GAO Huiyu SUN Jianping GU W.M.HUANG College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics School of mechanical and Aerospace Engineering Nanyang Technological University Jiangsu key laboratory of Advanced structural Materials and Application Technology School of Materials Science and EngineeringNanjing Institute of Technology

Currently, there are a limited number of dynamic models available for braided composite plates with large overall motions, despite the incorporation of three-dimensional(3D) braided composites into rotating blade components. In this paper, a dynamic model of 3D 4-directional braided composite thin plates considering braiding directions is established. Based on Kirchhoff's plate assumptions, the displacement variables of the plate are expressed. By incorporating the braiding directions into the constitutive equation of the braided composites, the dynamic model of the plate considering braiding directions is obtained. The effects of the speeds, braiding directions, and braided angles on the responses of the plate with fixed-axis rotation and translational motion, respectively, are investigated. This paper presents a dynamic theory for calculating the deformation of 3D braided composite structures undergoing both translational and rotational motions. It also provides a simulation method for investigating the dynamic behavior of non-isotropic material plates in various applications.

关键词： braiding direction composite thin plate dynamic model large overall motion O313.7 three-dimensional (3D) braided composite

Nonlinear stress analysis of aero-engine pipeline based on semi-analytical method

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Applied Mathematics and Mechanics(English Edition) 2025年第3期46卷 521-538页

作者： Weijiao CHEN Xiaochi QU Ruixin ZHANG Xumin GUO Hui MA Bangchun WEN School of mechanical Engineering and Automation Northeastern University key laboratory of vibration and Control of Aero-Propulsion Systems Ministry of Education of China Northeastern University

Fatigue failure caused by vibration is the most common type of pipeline failure. The core of this research is to obtain the nonlinear dynamic stress of a pipeline system accurately and efficiently, a topic that needs to be explored in the existing literature. The shell theory can better simulate the circumferential stress distribution, and thus the Mindlin-Reissner shell theory is used to model the pipeline. In this paper, the continuous pipeline system is combined with clamps through modal expansion for the first time,which realizes the coupling problem between a shell and a clamp. While the Bouc-Wen model is used to simulate the nonlinear external force generated by a clamp, the nonlinear coupling characteristics of the system are effectively captured. Then, the dynamic equation of the clamp-pipeline system is established according to the Lagrange energy equation. Based on the resonance frequency and stress amplitude obtained from the experiment, the nonlinear parameters of the clamp are identified with the semi-analytical method(SAM) and particle swarm optimization(PSO) algorithm. This study provides a theoretical basis for the clamp-pipeline system and an efficient and universal solution for stress prediction and analysis of pipelines in engineering.

关键词： Stress analysis

Enhancing forecasting of current-carrying performance through spatial frequency analysis of interface morphology

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Science China(Technological Sciences) 2025年第2期68卷 167-177页

作者： Nian YIN Zishuai WU Zhangli HOU Yiwei ZHANG Zhinan ZHANG State key laboratory of mechanical System and vibration Shanghai Jiao Tong UniversityShanghai 200240China School of mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Electrical contact interfaces,integral to devices such as connectors,switches,and conductive slip rings,play a crucial role in determining current-carrying *** study adopts spatial frequency analysis to assess the currentcarrying performance of interfaces based on their morphological ***,rough surfaces with various parameters,including the cutoff frequency(N),the spectral index(β),and the gain factor(A),were generated using spatial frequency methods,followed by current-carrying *** findings reveal that the characteristic parameters derived from spatial frequency methods exhibit a significantly stronger correlation with current-carrying performance than traditional roughness *** enhance the practical applicability of this research,a physical-informed machine learning approach for rough surface features extraction was developed,demonstrating high predictive parameter identification accuracy for the three ***,this paper introduces a tribo-informatics approach for analyzing and extracting rough surface features that considers the curvature characteristics of contact *** approach holds significant potential for evaluating the processing state of current-carrying interfaces,selecting high-quality surfaces,and forecasting current-carrying performances.

关键词： tribo-informatics current-carrying interfaces spatial frequency analysis machine learning

Achieving further refinement of grain structure and improvement of mechanical properties in Al-12Si-4Cu-2Ni-1Mg alloy by Al-Ti-C-B master alloy addition and deep cryogenic treatment

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China Foundry 2025年第1期22卷 75-82页

作者： Lin-fei Xia Wen-bo Li Zuo-shan Wei Yu-ying Wu Xiang-fa Liu China key laboratory for Liquid-Solid structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China Shandong key laboratory of Advanced Aluminum Materials and Technology Binzhou Institute of TechnologyBinzhou 256600ShandongChina

Near-eutectic Al-Si alloys are widely used in automotive manufacturing due to their superior wear resistance and high temperature *** of high Si content,the grain refinement of near-eutectic Al-Si alloy has been a problem for many *** this study,the effect of deep cryogenic treatment(DCT)on the microstructure and mechanical properties of Al-12Si-4Cu-2Ni-Mg alloy with addition of Al-Ti-C-B master alloy was fully *** show that the average grain size of the alloy is greatly reduced from 0.92 mm to 0.50 mm,and the eutectic Si and Al7Cu4Ni precipitates are spheroidized and refined in Al-12Si-4Cu-2Ni-Mg after DCT for 24 h and aging *** these changes of microstructures result in a significant increment of about 22.5%in elongation and a slight enhancement of about 6.8%in tensile ***,the refinement of microstructure also significantly improves the fatigue life of the alloy.

关键词： deep cryogenic treatment near-eutectic Al-Si master alloy microstructure mechanical properties

Significant improvement of machinability of C_(f)/SiC composites through matching laser scanning spacing and abrasive belt grain size

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Chinese Journal of Aeronautics 2025年第1期38卷 185-201页

作者： Guijian XIAO Zhengyu YANG Kun ZHOU Yi HE Xin LI College of mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China State key laboratory of mechanical Transmissions for Advanced Equipment Chongqing UniversityChongqing 400044China

To improve the application and service of C_(f)/SiC composites as advanced hightemperature structural materials,it is critical to achieve their high-efficiency and low-damage *** this study,the laser-ablating assisted grinding(LAAG)method was presented,and the connection of damage behavior and removal mechanism with laser and grinding processes was *** results demonstrated that the surface of C_(f)/SiC composites after laser ablation was covered with a substantial number of loose oxides primarily composed of *** ablating process,grinding parameter and abrasive belt selection have a significant impact on the machining *** fabricating an ablative layer with small laser scanning spacing,and selecting small abrasive grains and feed rate during grinding,the machinability was improved and a relatively lowerdamage grinding surface could be *** the optimal combination of process parameters,the grinding force and temperature of LAAG could be reduced by up to 85%and 35%,*** this case,the subsurface damage of C_(f)/SiC composites occurred only in the form of microcracks rather large-scale fracture,and the formation of interface debonding and matrix cracking was significantly ***,the grinding chips were mostly shown as micron-sized powders,indicating that the removal mechanism of C_(f)/SiC composites was primarily the microfractured and attrition wear of laser-ablated layer.

关键词： Ceramic matrix composites Laser ablating Grinding Material removal Fracture damage