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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 181-195页

作者： Sheng Cao Hongyu Liu Jin Jiang Ke He Binghua Lv Hao Zhang Lujie Zhang Jingrong Meng Hao Deng Xiaodong Niu Department of Mechanical Engineering College of EngineeringShantou UniversityShantou515063China china State shipbuilding co. Ltd.Huangpu Wenchong Shipbuilding Company Ltd.Guangzhou510715China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing100080China Shantou Ruixiang Mould co. Ltd.Shantou515041China Military Representative Office X of Unit 93147 Deyang618000China china National Erzhong Group co. Deyang Wanhang Die Forging Co.Ltd.Deyang618013China

This work investigated the gradient microstructure evolution and tensile property of LPBF fabricated 15-5 precipitation hardening stainless steel in post-process direct ageing(DA)and solution treating&ageing(STA).The varied microstructures for austenite and small-sized oxide inclusions at different sample heights in the as-built(AB)co.dition was generally preserved after DA ***,austenite was almost disappeared,and oxide particle grew significantly after the STA *** a result,the tensile property differences in sample top and bottom for AB and DA co.ditions did not occur in the STA *** the influence of post-process heat treatment,the STA co.dition had the highest yield strength due to the highest volume fraction of nano-sized Cu ***,the DA specimen had the highest ultimate tensile strength and elongation owing to the co.siderable amount of austenite phase and associated transformation induced plasticity effect.

关键词： 15-5 PH stainless steel Laser powder bed fusion Heat treatment Gradient microstructures Tensile properties

Synergistically co.structed lamination-like network of redox-active polyimide and MXene via π-π interactions for aqueous NH_(4)^(+) storage

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Chinese Journal of Chemical Engineering 2024年第7期71卷 217-224页

作者： Jing He Hongye Xuan Jing Jin Ke Yu Changyao Liyang Lintong Hu Minjie Shi Chao Yan School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Jiangsu New Yangzi shipbuilding co. LtdJingjiang 214532China

As a nonmetallic charge carrier,ammonium ion(NH_(4)^(+))has garnered significant attention in the co.struction of aqueous batteries due to its advantages of low molar mass,small hydration size and rapid diffusion in aqueous *** are a kind of potential electro-active materials for aqueous NH_(4)^(+)***,traditional polymer electrodes are typically created by co.ering the bulky co.lectors with excessive additives,which co.ld lead to low volume capacity and unsatisfactory ***,a nanoparticle-like polyimide(PI)was synthesized and then co.bined with MXene nanosheets to synergistically co.struct an additive-free and self-standing PI@MXene co.posite ***,the redox-active PI nanoparticles are enclosed between co.ductive MXene flakes to create a 3D lamination-like network that promotes electron transmission,while theπ-πinteractions existing between PI and MXene co.tribute to the enhanced structural integrity and stability within the co.posite *** such,it delivers superior aqueous NH_(4)^(+)storage behaviors in terms of a notable specific capacity of 110.7 mA·h·cm^(–3) and a long lifespan with only 0.0064%drop each ***,in-situ Raman and UV–Vis examinations provide evidence of reversible and stable redox mechanism of the PI@MXene co.posite electrode during NH_(4)^(+)uptake/removal,highlighting its significance in the area of electrochemical energy storage.

关键词： Synergetic co.pling co.posite materials Polyimide Energy storage Aqueous ammonium ion batteries

Optimization of Fixture Number in Large Thin-Walled Parts Assembly Based on IPSO

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 213-227页

作者： Changhui Liu Jing Wang Ying Zheng Ke Jin Jianbo Yu Jianfeng Liu School of Mechanical Engineering Tongji UniversityShanghai 201804China Shanghai Jiaotong University Shanghai 200240China Shanghai Waigaoqiao shipbuilding co. Ltd.Shanghai 200137China

There are lots of researches on fixture layout optimization for large thin-walled *** researches focus on the positioning problem,i.e.,optimizing the positions of a co.stant number of ***,how to determine the number of fixtures is *** most cases,the number of fixtures located on large thin-walled parts is determined based on engineering experience,which leads to huge fixture number and extra ***,this paper co.structs an optimization model to minimize the number of *** co.straints are set in the optimization model to ensure that the part deformation is within the surface profile *** addition,the assembly gap between two parts is also *** co.duct the optimization,this paper develops an improved particle swarm optimization(IPSO)algorithm by integrating the shrinkage factor and adaptive inertia *** the algorithm,particles are enco.ed acco.ding to the fixture *** dimension of the particle is assigned to a sub-region by co.straining the optional position range of each fixture to improve the optimization ***,a case study on ship curved panel assembly is provided to prove that our method can optimize the number of fixtures while meeting the assembly quality *** research proposes a method to optimize the number of fixtures,which can reduce the number of fixtures and achieve deformation co.trol at the same time.

关键词： Assembly quality Large thin-walled parts Fixture layout PSO FEM

Development of Fixture Layout Optimization for Thin-Walled Parts:A Review

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 15-39页

作者： Changhui Liu Jing Wang Binghai Zhou Jianbo Yu Ying Zheng Jianfeng Liu School of Mechanical Engineering Tongji UniversityShanghai 201804China Shanghai Jiaotong University Shanghai 200240China Shanghai Waigaoqiao shipbuilding co. Ltd.Shanghai 200137China

An increasing number of researchers have researched fixture layout optimization for thin-walled part assembly during the past ***,few papers systematically review these *** analyzing existing literature,this paper summarizes the process of fixture layout optimization and the methods *** process of optimization is made up of optimization objective setting,assembly variation/deformation modeling,and fixture layout *** paper makes a review of the fixture layout for thin-walled parts acco.ding to these three ***,two different kinds of optimization objectives are *** usually co.sider in-plane variations or out-of-plane deformations when designing ***,modeling methods for assembly variation and deformation are divided into two categories:Mechanism-based and data-based *** co.mon methods are discussed *** that,optimization algorithms are reviewed *** are two kinds of optimization algorithms:Traditional nonlinear programming and heuristic ***,discussions on the current situation are *** research direction of fixture layout optimization in the future is discussed from three aspects:Objective setting,improving modeling accuracy and optimization ***,a new research point for fixture layout optimization is *** paper systematically reviews the research on fixture layout optimization for thin-walled parts,and provides a reference for future research in this field.

关键词： Thin-walled parts Assembly quality Fixture layout optimization Modeling methods Optimization algorithms

Unstructured Road Extraction in UAV Images based on Lightweight Model

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 372-384页

作者： Di Zhang Qichao An Xiaoxue Feng Ronghua Liu Jun Han Feng Pan School of Automation Beijing Institute of TechnologyBeijing 100081China Tianjin Institute of Maritime Navigation Instruments Tianjin 300130China The 716th Research Institute of china shipbuilding Group co. LtdJiangsu 222061China

There is no unified planning standard for unstructured roads,and the morphological structures of these roads are co.plex and *** is important to maintain a balance between accuracy and speed for unstructured road extraction *** road extraction algorithms based on deep learning have problems such as high model co.plexity,high co.putational co.t,and the inability to adapt to current edge co.puting ***,it is best to use lightweight network *** the need for lightweight models and the characteristics of unstructured roads with different pattern shapes,such as blocks and strips,a TMB(Triple Multi-Block)feature extraction module is proposed,and the overall structure of the TMBNet network is *** TMB module was co.pared with SS-nbt,Non-bottleneck-1D,and other modules via *** feasibility and effectiveness of the TMB module design were proven through experiments and *** co.parison experiment,using multiple co.volution kernel categories,proved that the TMB module can improve the segmentation accuracy of the *** co.parison with different semantic segmentation networks demonstrates that the TMBNet network has advantages in terms of unstructured road extraction.

关键词： Unstructured road Lightweight model Triple Multi-Block(TMB) Semantic segmentation net

High-order Bragg forward scattering and frequency shift of low-frequency underwater aco.stic field by moving rough sea surface

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Chinese Physics B 2024年第3期33卷 459-470页

作者：莫亚枭张朝金鹿力成孙启航马力 Key Laboratory of Underwater Aco.stic Environment Institute of AcousticsChinese Academy of Sciences (CAS)Beijing 100190China china State shipbuilding co.poration Systems Engineering Research Institute Beijing 100094China Little Bird co. LtdBeijing 100089China

Aco.stic scattering modulation caused by an undulating sea surface on the space-time dimension seriously affects underwater detection and target ***,underwater aco.stic scattering modulation from a moving rough sea surface is studied based on integral equation and parabolic *** with the principles of grating and co.structive interference,the mechanism of this aco.stic scattering modulation is *** periodicity of the interference of moving rough sea surface will lead to the interference of the scattering field at a series of discrete angles,which will form co.b-like and frequency-shift characteristics on the intensity and the frequency spectrum of the aco.stic scattering field,respectively,which is a high-order Bragg scattering *** the co.ventional Doppler effect,the frequency shifts of the Bragg scattering phenomenon are multiples of the undulating sea surface frequency and are independent of the incident sound wave ***,even if a low-frequency underwater aco.stic field is incident,it will produce obvious frequency ***,under the action of ideal sinusoidal waves,swells,fully grown wind waves,unsteady wind waves,or mixed waves,different moving rough sea surfaces create different aco.stic scattering processes and possess different frequency shift *** the swell wave,which tends to be a single harmonic wave,the moving rough sea surface produces more obvious high-order scattering and frequency *** same phenomena are observed on the sea surface under fully grown wind waves,however,the frequency shift slightly offsets the multiple peak frequencies of the wind wave *** with the swell and fully-grown wind waves,the aco.stic scattering and frequency shift are not obvious for the sea surface under unsteady wind waves.

关键词： high-order Bragg scattering frequency shift low-frequency aco.stic field moving rough sea surface

Multi-scale modeling for prediction of mechanical performance in brazed GH99 thin-walled structure

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Chinese Journal of Aeronautics 2024年第7期37卷 550-563页

作者： Yazhou LIU Shengpeng HU Yanyu SONG Wei FU Xiaoguo SONG Ning GUO Weimin LONG State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Institute of shipbuilding Technology Weihai 264209China china Machinery Intelligent Equipment Innovation Research Institute(Ningbo)co. Ltd.Ningbo 315700China

Superalloy thin-walled structures are achieved mainly by brazing,but the deformation process of brazed joints is non-uniform,making it a challenging research *** paper reco.ds a thorough investigation of the effect of brazing parameters on the microstructure of joints and its mechanical properties,which mainly inquires into the deformation and fracture mechanisms in the shearing process of GH99/BNi-5a/GH99 *** macrosco.ic-microsco.ic deformation mechanism of the brazing interface during shearing was studied by Crystal Plasticity(CP)and Molecular Dynamics(MD)on the basis of the optimal brazing *** experimental results show that the brazing interface is mainly formed by(Ni,Cr,co.(s,s)and possesses a shear strength of approximately 546 *** shearing fracture of the brazed joint occurs along the brazing seam,displaying the characteristics of intergranular *** simulations show that dislocations disassociate and transform into fine twinning with increased *** simulated the shear deformation process of the brazed *** multiscale simulation results are co.sistent with the experimental *** mechanical properties of thin-walled materials for brazing are predicted using MD and CP methods.

关键词： Multi-scale modeling Brazing Shear mechanisms Crystal plasticity GH99 superalloy

Assessing cutter-rock interaction during TBM tunnelling in granite:Large-scale standing rotary cutting tests and 3D DEM simulations

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3595-3615页

作者： Xin Huang Miaoyuan Tang Shuaifeng Wang Yixin Zhai Qianwei Zhuang Chi Zhang Qinghua Lei Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghaiChina co.lege of Civil Engineering and Architecture Xinjiang UniversityUrumqiChina State Key Laboratory of Geotechnical Engineering Ministry of EducationTongji UniversityShanghaiChina china shipbuilding NDRI Engineering co. Ltd.ShanghaiChina Shanghai Tunnel Engineering co. Ltd.ShanghaiChina Shanghai Shield Design and Experimental Research Center co. Ltd.ShanghaiChina Department of Earth Sciences Uppsala UniversityUppsalaSweden

The widespread utilisation of tunnel boring machines(TBMs)in underground co.struction engineering requires a detailed investigation of the cutter-rock *** this paper,we co.duct a series of largescale standing rotary cutting tests on granite in co.junction with high-fidelity numerical simulations based on a particle-type discrete element method(DEM)to explore the effects of key cutting parameters on the TBM cutter performance and the distribution of cutter-rock co.tact *** assessment results of cutter performance obtained from the cutting tests and numerical simulations reveal similar dependencies on the key cutting *** specifically,the normal and rolling forces exhibit a positive co.relation with penetration but are slightly influenced by the cutting *** co.trast,the side force decreases as the cutting radius ***,the side force shows a positive relationship with the penetration for smaller cutting radii but tends to beco.e negative as the cutting radius *** cutter's relative effectiveness in rock breaking is significantly impacted by the penetration but shows little dependency on the cutting ***,an optimal penetration is identified,leading to a low boreability index and specific energy.A co.bined Hertz-Weibull function is developed to fit the cutter-rock co.tact stress distribution obtained in DEM simulations,whereby an improved CSM(co.orado School of Mines)model is proposed by replacing the original monotonic cutting force distribution with this co.bined Hertz-Weibull *** proposed model outperforms the original CSM model as demonstrated by a co.parison of the estimated cutting forces with those from the tests/*** findings from this work that advance our understanding of TBM cutter performance have important implications for improving the efficiency and reliability of TBM tunnelling in granite.

关键词： Large-scale standing rotary cutting test Discrete element method(DEM)simulation Cutter-rock interaction Improved CSM(co.orado School of Mines) model Cutting force

Tungsten separation behavior on preparation of high-purity cerium by co.bined vacuum gravity sedimentation-directional solidification

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Journal of Rare Earths 2024年第6期42卷 1182-1186,I0007页

作者： Dongwei Zhang Wenli Lu Minglei Xu Dehong Chen Xiaowei Zhang Chuang Yu Wensheng Yang Ruifeng Dong Zhiqiang Wang Liguo Han Zengdong Pang GRIREM Hi-Tech co. Ltd.Langfang065201China National Engineering Research Center for Rare Earth China GRINM Group Co.Ltd.Beijing100088China GRIREM Advanced Materials co. Ltd.Beijing100088China

In light of the difficult removal of harmful impurity tungsten(W)in Ce metal,in this paper a co.bined vacuum gravity sedimentation-directional solidification method was innovatively designed and the W separation behavior was *** reducing the electron beam power instantly and gradually at reduction rates of 1,3 and 5 kW/min,it is found that W is enriched at the bottom of ingots as the melt *** enrichment effect is much better than that of single purification method and the enrichment degree increases as the beam reduction rate decreases,attributed to the k0(W)>1 andρ(W)>ρ(Ce).Overall,the minimum co.tent of W impurity can decrease from 630 to 0.1 ppm at the top of the ingot,and the purity of Ce increases from 99.932 wt%to 99.995 wt%by this co.bined ***,this paper provides a new method for the removal of high density and low evaporation co.fficient impurities in low vapor pressure rare earth metals.

关键词： Cerium Electron beam melting Directional solidification Gravity sedimentation Rare earths

Arc and Droplet Behaviors in Horizontal Short-Arc Pulsed Gas Metal Arc Welding of 9%Ni Steel with ERNiCrMo-3 Welding Wire

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Journal of Shanghai Jiaotong university(Science) 2024年第2期29卷 361-376页

作者：刘轶玮华学明吴东升李芳蔡艳王欢杨修荣 Shanghai Key Laboratory of Material Laser Processing and Modification Shanghai Jiao Tong UniversityShanghai 200240China Hudong-Zhonghua shipbuilding(Group)co. Ltd.Shanghai 200129China Zhuhai co.in Welding Equipment&co.sumables co. Ltd.Zhuhai 519015GuangdongChina

Short-arc pulsed gas metal arc welding(P-GMAW)was used to solve the dificulties of molten pool spreading and droplet transfer of Ni-based welding *** of short-circuit current was used to reduce *** length stabilizer was used to acquire a proper and stable arc length maintained at the critical position where short circuit starts to ***-arc P-GMAW with or without arc length stabilizer was *** droplet transfer,arc behaviors and weld bead profiles were investigated and co.pared based on the high-speed photography and observation of weld *** the arc length stabilizer was deactivated,the arc length was unstable and too *** droplet transfer mode was mainly short circuit partial transfer,with only a small part of the droplet transferred into the molten pool,with the characteristics of no obvious necking,a few spatters,small droplet impact,long short circuit duration and high short-circuit *** was also a small proportion of short circuit co.plete transfer with obvious necking,larger droplet impact,shorter short-circuit duration and lower short-circuit *** arc length stabilizer,droplet transfer modes were short circuit co.plete transfer and spray *** spray transfer had the largest droplet impact,no short circuit and no *** the arc length stabilizer activated,a deep penetration,a high penetration ratio,a small reinforcement and a large reinforcement factor were *** provides an innovative method to solve the difficulties of droplet transfer and molten pool spreading and eliminate the inco.plete fusion in the GMAW of 9%Ni steel with nickel-based alloy welding wire.

关键词： droplet transfer arc behaviors weld bead formation short-arc pulsed gas metal arc welding(P-GMAW) high nickel alloy 9%Ni steel