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Effect of cooling media on bead geometry,microstructure,and mechanical properties of wire arc additive manufactured IN718 alloy

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Advances in Manufacturing 2024年第1期12卷 124-149页

作者： Parveen Kumar Satish Kumar Sharma Ratnesh Kumar Raj Singh Department of mechanical engineering Thapar Institute of Engineering and TechnologyPatialaPunjab147004India

This work aims to present and explore thermal management techniques for the wire arc additive manufacturing(WAAM)of IN718 *** heat can be mitigated via air or water *** this study,the material was deposited under four different heat-input conditions with air or water *** air cooling,the layer is deposited in a normal atmospheric air environment,whereas with water cooling,the material is deposited inside a water tank by varying the water *** validate the air and water cooling thermal management techniques,IN718 single-pass and multilayer linear walls were deposited using the bidirectional gas metal arc welding based WAAM setup under four different heat input *** the deposition of single layers,the temperature profiles were recorded,and the geometric and microstructural features were *** multilayer wall structures,the mechanical properties(hardness,tensile strength,and elongation)were determined and assessed using the corresponding microstructural features explored through scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and electron backscatter diffraction(EBSD)*** microstructure observed through SEM analysis in the building direction was found to be nonhomogenous compared with that in the deposition ***,water cooling was found to govern bead characteristics,such as wall width and *** grain size and anisotropy of the mechanical properties also decreased in the water-cooled ***,water cooling is an economical and efficient method to mitigate excessive heat accumulation in WAAM-deposited IN718.

关键词： Air cooling Water cooling IN718 Bead characteristics Microstructure Electron backscatter diffraction(EBSD)

Nonlinear Absorption and Low-threshold Two-photon Pumped Amplified Stimulated Emission from FAPbBr_(3) Nanocrystals

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发光学报 2024年第8期45卷 1281-1291页

作者： WANG Yajuan TAY Yong Kang Eugene WANG Fang YU Sheng SUM Tze Chien LIU Wei School of Materials and Chemical engineering Ningbo University of TechnologyNingbo 315211China School of Physical and Mathematical Sciences Nanyang Technological UniversitySingapore 637371Singapore College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityHangzhou 311300China

Formamidinium lead bromide(FAPbBr_(3))nanocrystals(NCs)have been considered to be a good optoelectronic material due to their pure green emission,excellent stability and superior carrier transport ***,two-photon pumped amplified spontaneous emission(ASE)and the corresponding nonlinear optical properties of FAPbBr_(3) NCs are scarcely ***,we synthesized colloidal FAPbBr_(3) NCs with different sizes by changing the molar ratio of FABr/PbBr_(2) in the precursor solution,using ligand assisted precipitation(LARP)technology at room ***(PL)and time resolved photoluminescence(TRPL)spectroscopy were measured to characterize their ASE *** their nonlinear optical properties were studied through the Zscan technique and the two-photon excited fluorescence *** stimulated emission properties including oneand two-photon pumped ASE have been realized from FAPbBr_(3) *** large two-photon absorption coefficient(0.27 cm/GW)and high non-linear absorption cross-section(7.52×10^(5) GM),ASE with threshold as low as 9.8μJ/cm^(2) and 487μJ/cm^(2) have been obtained from colloidal FAPbBr_(3) NCs using one-and two-photon *** results indicate that as a new possible green-emitting frequency-upconversion material with low thresholds,FAPbBr_(3) NCs hold great potential in the development of high-performance two-photon pump lasers.

关键词： perovskites formamidinium lead bromide nanocrystals nonlinear optical gain amplified spontaneous emission

Bearing Fault Diagnosis Based on Deep Discriminative Adversarial Domain Adaptation Neural Networks

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Computer Modeling in engineering & Sciences 2024年第3期138卷 2619-2640页

作者： Jinxi Guo Kai Chen Jiehui Liu Yuhao Ma Jie Wu Yaochun Wu Xiaofeng Xue Jianshen Li School of mechanical and Equipment engineering Hebei University of EngineeringHandan056000China College of mechanical engineering Anyang Institute of TechnologyAnyang455000China Department of mechanical and electrical engineering Yuncheng UniversityYuncheng044000China

Intelligent diagnosis driven by big data for mechanical fault is an important means to ensure the safe operation ofequipment. In these methods, deep learning-based machinery fault diagnosis approaches have received increasingattention and achieved some results. It might lead to insufficient performance for using transfer learning alone andcause misclassification of target samples for domain bias when building deep models to learn domain-invariantfeatures. To address the above problems, a deep discriminative adversarial domain adaptation neural networkfor the bearing fault diagnosis model is proposed (DDADAN). In this method, the raw vibration data are firstlyconverted into frequency domain data by Fast Fourier Transform, and an improved deep convolutional neuralnetwork with wide first-layer kernels is used as a feature extractor to extract deep fault features. Then, domaininvariant features are learned from the fault data with correlation alignment-based domain adversarial ***, to enhance the discriminative property of features, discriminative feature learning is embeddedinto this network to make the features compact, as well as separable between classes within the class. Finally, theperformance and anti-noise capability of the proposedmethod are evaluated using two sets of bearing fault *** results demonstrate that the proposed method is capable of handling domain offset caused by differentworkingconditions and maintaining more than 97.53% accuracy on various transfer tasks. Furthermore, the proposedmethod can achieve high diagnostic accuracy under varying noise levels.

关键词： Fault diagnosis transfer learning domain adaptation discriminative feature learning correlation alignment

An Improved Coupled Level Set and Continuous Moment-of-Fluid Method for Simulating Multiphase Flows with Phase Change

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1034-1069页

作者： Zhouteng Ye Cody Estebe Yang Liu Mehdi Vahab Zeyu Huang Mark Sussman Alireza Moradikazerouni Kourosh Shoele Yongsheng Lian Mitsuhiro Ohta M.Yousuff Hussaini ZJUI institute Zhejiang UniversityHaining 314400ZhejiangChina Department of Mathematics Florida State UniversityTallahasseeUSA Department of mechanical engineering Florida State UniversityTallahasseeUSA mechanical and Aerospace engineering Mathworks NatickMAUSA School of Aerospace engineering Tsinghua UniversityBeijing 100084China Department of mechanical engineering University of LouisvilleLouisvilleUSA Department of mechanical Science Tokushima UniversityTokushimaJapan

An improved algorithm for computing multiphase flows is presented in which the multimaterial Moment-of-Fluid(MOF)algorithm for multiphase flows,initially described by Li et al.(2015),is enhanced addressing existing MOF difficulties in computing solutions to problems in which surface tension forces are crucial for understanding salient flow *** Continuous MOF(CMOF)method is motivated in this *** CMOF reconstruction method inherently removes the"checkerboard instability"that persists when using the MOF method on surface tension driven multiphase(multimaterial)*** CMOF reconstruction algorithm is accelerated by coupling the CMOF method to the level set method and coupling the CMOF method to a decision tree machine learning(ML)*** flow examples are shown in the two-dimensional(2D),three-dimensional(3D)axisymmetric"RZ",and 3D coordinate *** include two material and three material multiphase flows:bubble formation,the impingement of a liquid jet on a gas bubble in a cryogenic fuel tank,freezing,and liquid lens dynamics.

关键词： Moment-of-Fluid(MOF) Surface tension Two phase flow Phase change Deforming boundaries with change(s)in topology Two-dimensional(2D) Three-dimensional(3D)axisymmetric 3D

Exploring the Effect of Plasticity on the Phase Imaging of TM-AFM Through Molecular Dynamics Simulations

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Acta Mechanica Solida Sinica 2024年第2期37卷 297-304页

作者： Guolin Liu Yu Zeng Yaxin Chen Zheng Wei School of mechanical and electrical engineering Beijing University of Chemical TechnologyBeijing100029China

In the tapping-mode atomic force microscope(TM-AFM),the probe tip continuously taps the sample surface,which may cause plastic deformation of the sample and result in energy *** energy dissipation of the probe is closely related to the scanned phase *** quantify the energy dissipation due to plastic indentations of the sample,this study utilized a combination of molecular dynamics(MD)simulations and experiments on single-crystal copper samples,including multiple nano-indentation *** energy dissipation of the probe due to the plastic deformation of the sample was calculated by integrating the hysteresis curve of the indentation depth versus the force applied to the *** simulation results are in good agreement with the experimental *** sets of results have demonstrated that the plastic energy dissipation decreases as the number of indentations increases,and eventually the energy of the probe tends to *** equilibrium energy dissipation is associated with other dissipation ***,it was observed that,after hundreds of taps,the dissipated energy of plastic deformation could be ignored,implying that the scanned image may not reflect the plasticity information of the sample after multiple taps of the probe on the sample surface for scanning.

关键词： Atomic force microscopy Force-distance curves Nano-indentations Plasticity Molecular dynamics

Realization of nonreciprocal acoustic energy transfer using an asymmetric strong nonlinear vibroacoustic system

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International Journal of mechanical System Dynamics 2024年第1期4卷 99-114页

作者： Jiangming Jin Jingxiao Huang Yuepeng Xiao Sound and Vibration Laboratory College of Mechanical EngineeringZhejiang University of TechnologyHangzhouChina

In this paper,an asymmetric vibroacoustic system that can passively realize nonreciprocal transmission of acoustic energy is *** experimental system consists of a waveguide,a strongly nonlinear membrane,and three acoustic cavities with different *** theoretical modeling of the system is verified by experiments,and parametric analysis is also carried *** intensive studies reveal the nonreciprocal transmission of acoustic energy in this prototype *** forward excitation,internal resonance between the two nonlinear normal modes of the vibroacoustic system occurs,and acoustic energy is irreversibly transferred from the waveguide to the nonlinear ***,under backward excitation,there is no internal resonance in the *** spectra and wavelet analysis are used to highlight the mechanism of nonreciprocal transfer of acoustic ***,nearly unidirectional(preferential)transmission of acoustic energy transfer is shown by this *** nonreciprocal acoustic energy transfer method illustrated in this paper provides a new way to design the odd acoustic element.

关键词： vibroacoustic system acoustic nonreciprocity nonlinear normal mode transient resonance capture

Near resonance vibration isolation on a levered-dual response(LEDAR)Coulomb-damped system by differential preloads/offsets in linear springs

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1033-1050页

作者： T.I.TOLUWALOJU C.K.THEIN D.HALIM Department of mechanical Materials and Manufacturing EngineeringUniversity of Nottingham Ningbo ChinaNingbo 315100Zhejiang ProvinceChina Nottingham Ningbo China Beacons of Excellence Research and Innovation institute University of Nottingham Ningbo ChinaNingbo 315048Zhejiang ProvinceChina

The levered-dual response(LEDAR)Coulomb-damped system attains near resonant vibration isolation by differential preloads/offsets in linear *** takes the advantages of both the preloads/offsets in linear springs and the guiderail friction for realizing different levels of vibration *** isolation capacities are investigated on the strategies with both the horizontal and vertical guiderails,with the horizontal rail only,and without *** compressive preloads generally result in the consumption of most of the initial excitation energy so as to overcome the potential *** isolation onsets at the frequency ratio of 1∓0.095 on the left-hand side(LHS)and the right-hand side(RHS)of the lever are relative to the load plate *** observed near resonant isolation thus makes the LEDAR system a candidate for the isolation of the mechanical systems about resonance while opening a path for simultaneous harvesterisolation functions and passive functions at extreme frequencies.

关键词： lever ratio Coulomb damping preload tension/compression isolation band/depth offset potential

3D printed grafts with gradient structures for organized vascular regeneration

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International Journal of Extreme Manufacturing 2024年第3期6卷 505-520页

作者： Yuewei Chen Zhongfei Zou Tao Fu Zhuang Li Zhaojie Zhang Meng Zhu Qing Gao Shaofei Wu Guosheng Fu Yong He Jiayin Fu State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China School of mechanical engineering Guizhou UniversityGuiyang 550025People’s Republic of China Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of zhejiang Province Department of CardiologySir Run Run Shaw HospitalZhejiang UniversityHangzhou 310016People’s Republic of China School of mechanical engineering Guizhou Institute of TechnologyGuiyang 550003People’s Republic of China Department of Oral and Maxillofacial Surgery The Second Affiliated Hospital of Zhejiang University School of MedicineSchool of Stomatologyand Key Laboratory of Oral Biomedical Research of Zhejiang ProvinceHangzhouZhejiang 310006People’s Republic of China

Synthetic vascular grafts suitable for small-diameter arteries(<6 mm) are in great ***,there are still no commercially available small-diameter vascular grafts(SDVGs) in clinical practice due to thrombosis and stenosi... 详细信息

Synthetic vascular grafts suitable for small-diameter arteries(mechanical properties mimicking natural *** by the collagen alignment of SML,the inner layer of the grafts had larger pore sizes and high porosity to accelerate the infiltration of cells and their circumferential alignment,which could facilitate SML reconstruction for compliance restoration and spontaneous *** outer layer was designed to induce fibroblast recruitment by low porosity and minor pore size and provide SDVG with sufficient mechanical *** month after implantation,the arteries regenerated by 3D-printed grafts exhibited better pulsatility than electrospun grafts,with a compliance(8.9%) approaching that of natural arteries(11.36%) and significantly higher than that of electrospun ones(1.9%).The 3D-printed vascular demonstrated a three-layer structure more closely resembling natural arteries while electrospun grafts showed incomplete endothelium and immature *** study shows the importance of SML reconstruction during vascular graft regeneration and provides an effective strategy to reconstruct blood vessels through 3D-printed structures rapidly.

关键词： small-diameter vascular graft smooth muscle layer 3D printing endothelialization

A Predictive Energy Management Strategies for Mining Dump Trucks

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Energy engineering 2024年第3期121卷 769-788页

作者： Yixuan Yu Yulin Wang Qingcheng Li Bowen Jiao College of mechanical and electrical engineering Qingdao UniversityQingdao266071China

The plug-in hybrid vehicles(PHEV)technology can effectively address the issues of poor dynamics and higher energy consumption commonly found in traditional mining dump ***,plug-in hybrid electric trucks can achieve excellent fuel economy through efficient energy management strategies(EMS).Therefore,a series hybrid system is constructed based on a 100-ton mining dump truck in this *** inspired by the dynamic programming(DP)algorithm,a predictive equivalent consumption minimization strategy(P-ECMS)based on the DP optimization result is *** on the optimal control manifold and the SOC reference trajectory obtained by the DP algorithm,the P-ECMS strategy performs real-time stage parameter optimization to obtain the optimal equivalent factor(EF).Finally,applying the equivalent consumption minimization strategy(ECMS)realizes real-time *** simulation results show that the equivalent fuel consumption of the P-ECMS strategy under the experimentally collected mining cycle conditions is 150.8 L/100 km,which is 10.9%less than that of the common CDCS strategy(169.3 L/100 km),and achieves 99.47%of the fuel saving effect of the DP strategy(150 L/100 km).

关键词： Mining dump truck energy management strategy plug-in hybrid electric vehicle equivalent consumption minimization strategy dynamic programming