资源类型

期刊论文 248

会议视频 18

会议专题 1

年份

2024 1

2023 29

2022 27

2021 19

2020 26

2019 14

2018 21

2017 21

2016 3

2015 7

2014 8

2013 10

2012 2

2011 6

2010 7

2009 15

2008 13

2007 13

2006 2

2005 3

展开 ︾

关键词

智能制造 5

高性能制造 3

增材制造 2

微反应器 2

微合金化 2

显微硬度 2

立堵截流 2

膨化硝酸铵 2

采油工程 2

高端计算 2

2021全球工程前沿 1

3D打印 1

AD9954 1

ATP荧光检测 1

Hilbert变换 1

LED战略性中心企业 1

LED高端制造装备 1

Mallat算法 1

Meyer小波变换 1

展开 ︾

检索范围：

排序： 展示方式：

3D finite element prediction of chip flow, burr formation, and cutting forces in micro end-milling of

A. DAVOUDINEJAD, P. PARENTI, M. ANNONI

《机械工程前沿（英文）》 2017年 第12卷 第2期   页码 203-214 doi: 10.1007/s11465-017-0421-6

摘要：

Predictive models for machining operations have been significantly improved through numerous methods in recent decades. This study proposed a 3D finite element modeling (3D FEM) approach for the micro end-milling of Al6061-T6. Finite element (FE) simulations were performed under different cutting conditions to obtain realistic numerical predictions of chip flow, burr formation, and cutting forces. FE modeling displayed notable advantages, such as capability to easily handle any type of tool geometry and any side effect on chip formation, including thermal aspect and material property changes. The proposed 3D FE model considers the effects of mill helix angle and cutting edge radius on the chip. The prediction capability of the FE model was validated by comparing numerical model and experimental test results. Burr dimension trends were correlated with force profile shapes. However, the FE predictions overestimated the real force magnitude. This overestimation indicates that the model requires further development.

关键词： 3D finite element modeling     micro end-milling     cutting force     chip formation     burr formation    

HTML PDF 收藏

Effect of Joule heating on electro-osmotic flow in a closed-end micro-channel with isothermal and convective

Liang ZHAO, Linhua LIU,

《能源前沿（英文）》 2009年 第3卷 第4期   页码 381-388 doi: 10.1007/s11708-009-0057-2

摘要： The effect of Joule heating on the steady state electro-osmotic flow in a closed-end micro-channel is studied through numerical simulation with the finite volume method. The velocity field and the temperature field are described by a rigorous mathematical model. Thermophysical properties including viscosity and thermal conductivity are considered to be temperature-dependent. The simulations show that the presence of Joule heating causes an increase in temperature and a decrease in viscosity in the whole micro-channel, which, thereafter, induce a large velocity near the wall and an increase in fluid velocity at the central region in order to maintain a zero flow rate at the cross section of the micro-channel. The effect of Joule heating on the induced pressure gradient is also studied, which is very important for the application of the closed-end micro-channel as a micro-actuator. The results reveal that the induced pressure gradient, taking into consideration Joule heating, is significantly smaller than that without considering Joule heating when the wall temperature of the micro-channel is constant. The induced pressure gradient difference between considering Joule heating and without considering Joule heating is small under the convective boundary condition.

关键词： closed-end micro-channel     electrical double layer     electro-osmotic flow     induced pressure gradient     Joule heating    

HTML PDF 收藏

Mesoscale fabrication of a complex surface for integral impeller blades

Xibin WANG,Tianfeng ZHOU,Lijing XIE,Li JIAO,Zhibing LIU,Zhiqiang LIANG,Pei YAN

《机械工程前沿（英文）》 2017年 第12卷 第1期   页码 116-131 doi: 10.1007/s11465-017-0426-1

摘要：

Integral impeller is the most important component of a mini-engine. However, the machining of a mesoscale impeller with a complex integral surface is difficult because of its compact size and high accuracy requirement. A mesoscale component is usually manufactured by milling. However, a conventional milling tool cannot meet the machining requirements because of its size and stiffness. For the fabrication of a complex integral impeller, a micro-ball-end mill is designed in accordance with the non-instantaneous-pole envelope principle and manufactured by grinding based on the profile model of the helical groove and the mathematical model of the cutting edge curve. Subsequently, fractal theory is applied to characterize the surface quality of the integral impeller. The fractal theory-based characterization shows that the completed mesoscale integral impeller exhibits a favorable performance in terms of mechanical properties and morphological accuracy.

关键词： mesoscale fabrication     micro-milling tool     mesoscale milling     impeller blade    

HTML PDF 收藏

Energy field-assisted high-speed dry milling green machining technology for difficult-to-machine metal

《机械工程前沿（英文）》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0744-9

摘要： Energy field-assisted machining technology has the potential to overcome the limitations of machining difficult-to-machine metal materials, such as poor machinability, low cutting efficiency, and high energy consumption. High-speed dry milling has emerged as a typical green processing technology due to its high processing efficiency and avoidance of cutting fluids. However, the lack of necessary cooling and lubrication in high-speed dry milling makes it difficult to meet the continuous milling requirements for difficult-to-machine metal materials. The introduction of advanced energy-field-assisted green processing technology can improve the machinability of such metallic materials and achieve efficient precision manufacturing, making it a focus of academic and industrial research. In this review, the characteristics and limitations of high-speed dry milling of difficult-to-machine metal materials, including titanium alloys, nickel-based alloys, and high-strength steel, are systematically explored. The laser energy field, ultrasonic energy field, and cryogenic minimum quantity lubrication energy fields are introduced. By analyzing the effects of changing the energy field and cutting parameters on tool wear, chip morphology, cutting force, temperature, and surface quality of the workpiece during milling, the superiority of energy-field-assisted milling of difficult-to-machine metal materials is demonstrated. Finally, the shortcomings and technical challenges of energy-field-assisted milling are summarized in detail, providing feasible ideas for realizing multi-energy field collaborative green machining of difficult-to-machine metal materials in the future.

关键词： difficult-to-machine metal material     green machining     high-speed dry milling     laser energy field-assisted milling     ultrasonic energy field-assisted milling     cryogenic minimum quantity lubrication energy field-assisted milling    

HTML PDF 收藏

Topology-independent end-to-end learning model for improving the voltage profile in microgrids-integrated

《能源前沿（英文）》 2023年 第17卷 第2期   页码 211-227 doi: 10.1007/s11708-022-0847-3

摘要： With multiple microgrids (MGs) integrated into power distribution networks in a distributed manner, the penetration of renewable energy like photovoltaic (PV) power generation surges. However, the operation of power distribution networks is challenged by the issues of multiple power flow directions and voltage security. Accordingly, an efficient voltage control strategy is needed to ensure voltage security against ever-changing operating conditions, especially when the network topology information is absent or inaccurate. In this paper, we propose a novel data-driven voltage profile improvement model, denoted as system-wide composite adaptive network (SCAN), which depends on operational data instead of network topology details in the context of power distribution networks integrated with multiple MGs. Unlike existing studies that realize topology identification and decision-making optimization in sequence, the proposed end-to-end model determines the optimal voltage control decisions in one shot. More specifically, the proposed model consists of four modules, Pre-training Network and modified interior point methods with adversarial networks (Modified IPMAN) as core modules, and discriminator generative adversarial network (Dis-GAN) and Volt convolutional neural network (Volt-CNN) as ancillary modules. In particular, the generator in SCAN is trained by the core modules in sequence so as to form an end-to-end mode from data to decision. Numerical experiments based on IEEE 33-bus and 123-bus systems have validated the effectiveness and efficiency of the proposed method.

关键词： end-to-end learning     microgrids     voltage profile improvement     generative adversarial network    

HTML PDF 收藏

Fiber-reinforced composites in milling and grinding: machining bottlenecks and advanced strategies

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0680-8

摘要： Fiber-reinforced composites have become the preferred material in the fields of aviation and aerospace because of their high-strength performance in unit weight. The composite components are manufactured by near net-shape and only require finishing operations to achieve final dimensional and assembly tolerances. Milling and grinding arise as the preferred choices because of their precision processing. Nevertheless, given their laminated, anisotropic, and heterogeneous nature, these materials are considered difficult-to-machine. As undesirable results and challenging breakthroughs, the surface damage and integrity of these materials is a research hotspot with important engineering significance. This review summarizes an up-to-date progress of the damage formation mechanisms and suppression strategies in milling and grinding for the fiber-reinforced composites reported in the literature. First, the formation mechanisms of milling damage, including delamination, burr, and tear, are analyzed. Second, the grinding mechanisms, covering material removal mechanism, thermal mechanical behavior, surface integrity, and damage, are discussed. Third, suppression strategies are reviewed systematically from the aspects of advanced cutting tools and technologies, including ultrasonic vibration-assisted machining, cryogenic cooling, minimum quantity lubrication (MQL), and tool optimization design. Ultrasonic vibration shows the greatest advantage of restraining machining force, which can be reduced by approximately 60% compared with conventional machining. Cryogenic cooling is the most effective method to reduce temperature with a maximum reduction of approximately 60%. MQL shows its advantages in terms of reducing friction coefficient, force, temperature, and tool wear. Finally, research gaps and future exploration directions are prospected, giving researchers opportunity to deepen specific aspects and explore new area for achieving high precision surface machining of fiber-reinforced composites.

关键词： milling     grinding     fiber-reinforced composites     damage formation mechanism     delamination     material removal mechanism     surface integrity     minimum quantity lubrication    

HTML PDF 收藏

Cutting Force Model for a Small-diameter Helical Milling Cutter

LI Xiwen, YANG Shuzi, YANG Mingjin, XIE Shouyong

《机械工程前沿（英文）》 2007年 第2卷 第3期   页码 272-277 doi: 10.1007/s11465-007-0047-1

摘要： In the milling process, the major flank wear land area (two-dimensional measurement for the wear) of a small-diameter milling cutter, as wear standard, can reflect actual changes of the wear land of the cutter. By analyzing the wearing characteristics of the cutter, a cutting force model based on the major flank wear land area is established. Characteristic parameters such as pressure parameter and friction parameter are calculated by substituting tested data into their corresponding equations. The cutting force model for the helical milling cutter is validated by experiments. The computational and experimental results show that the cutting force model is almost consistent with the actual cutting conditions. Thus, the cutting force model established in the research can provide a theoretical foundation for monitoring the condition of a milling process that uses a small-diameter helical milling cutter.

关键词： computational     corresponding     helical milling     theoretical foundation     Characteristic    

HTML PDF 收藏

Position-varying surface roughness prediction method considering compensated acceleration in milling

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 855-867 doi: 10.1007/s11465-021-0649-z

摘要： Machined surface roughness will affect parts’ service performance. Thus, predicting it in the machining is important to avoid rejects. Surface roughness will be affected by system position dependent vibration even under constant parameter with certain toolpath processing in the finishing. Aiming at surface roughness prediction in the machining process, this paper proposes a position-varying surface roughness prediction method based on compensated acceleration by using regression analysis. To reduce the stochastic error of measuring the machined surface profile height, the surface area is repeatedly measured three times, and Pauta criterion is adopted to eliminate abnormal points. The actual vibration state at any processing position is obtained through the single-point monitoring acceleration compensation model. Seven acceleration features are extracted, and valley, which has the highest R-square proving the effectiveness of the filtering features, is selected as the input of the prediction model by mutual information coefficients. Finally, by comparing the measured and predicted surface roughness curves, they have the same trends, with the average error of 16.28% and the minimum error of 0.16%. Moreover, the prediction curve matches and agrees well with the actual surface state, which verifies the accuracy and reliability of the model.

关键词： surface roughness prediction     compensated acceleration     milling     thin-walled workpiece    

HTML PDF 收藏

Mechanical behavior and semiempirical force model of aerospace aluminum alloy milling using nano biological

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0720-4

摘要： Aerospace aluminum alloy is the most used structural material for rockets, aircraft, spacecraft, and space stations. The deterioration of surface integrity of dry machining and the insufficient heat transfer capacity of minimal quantity lubrication have become the bottleneck of lubrication and heat dissipation of aerospace aluminum alloy. However, the excellent thermal conductivity and tribological properties of nanofluids are expected to fill this gap. The traditional milling force models are mainly based on empirical models and finite element simulations, which are insufficient to guide industrial manufacturing. In this study, the milling force of the integral end milling cutter is deduced by force analysis of the milling cutter element and numerical simulation. The instantaneous milling force model of the integral end milling cutter is established under the condition of dry and nanofluid minimal quantity lubrication (NMQL) based on the dual mechanism of the shear effect on the rake face of the milling cutter and the plow cutting effect on the flank surface. A single factor experiment is designed to introduce NMQL and the milling feed factor into the instantaneous milling force coefficient. The average absolute errors in the prediction of milling forces for the NMQL are 13.3%, 2.3%, and 7.6% in the x-, y-, and z-direction, respectively. Compared with the milling forces obtained by dry milling, those by NMQL decrease by 21.4%, 17.7%, and 18.5% in the x-, y-, and z-direction, respectively.

关键词： milling     force     nanofluid minimum quantity lubrication     aerospace aluminum alloy     nano biological lubricant    

HTML PDF 收藏

A hybrid deep learning model for robust prediction of the dimensional accuracy in precision milling of

《机械工程前沿（英文）》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0688-0

摘要： The use of artificial intelligence to process sensor data and predict the dimensional accuracy of machined parts is of great interest to the manufacturing community and can facilitate the intelligent production of many key engineering components. In this study, we develop a predictive model of the dimensional accuracy for precision milling of thin-walled structural components. The aim is to classify three typical features of a structural component—squares, slots, and holes—into various categories based on their dimensional errors (i.e., “high precision,” “pass,” and “unqualified”). Two different types of classification schemes have been considered in this study: those that perform feature extraction by using the convolutional neural networks and those based on an explicit feature extraction procedure. The classification accuracy of the popular machine learning methods has been evaluated in comparison with the proposed deep learning model. Based on the experimental data collected during the milling experiments, the proposed model proved to be capable of predicting dimensional accuracy using cutting parameters (i.e., “static features”) and cutting-force data (i.e., “dynamic features”). The average classification accuracy obtained using the proposed deep learning model was 9.55% higher than the best machine learning algorithm considered in this paper. Moreover, the robustness of the hybrid model has been studied by considering the white Gaussian and coherent noises. Hence, the proposed hybrid model provides an efficient way of fusing different sources of process data and can be adopted for prediction of the machining quality in noisy environments.

关键词： precision milling     dimensional accuracy     cutting force     convolutional neural networks     coherent noise    

HTML PDF 收藏

Multi-objective optimization of cutting parameters in high-speed milling based on grey relational analysis

Tao FU, Jibin ZHAO, Weijun LIU

《机械工程前沿（英文）》 2012年 第7卷 第4期   页码 445-452 doi: 10.1007/s11465-012-0338-z

摘要：

This paper investigates optimization problem of the cutting parameters in high-speed milling on NAK80 mold steel. An experiment based on the technology of Taguchi is performed. The objective is to establish a correlation among spindle speed, feed per tooth and depth of cut to the three directions of cutting force in the milling process. In this study, the optimum cutting parameters are obtained by the grey relational analysis. Moreover, the principal component analysis is applied to evaluate the weights so that their relative significance can be described properly and objectively. The results of experiments show that grey relational analysis coupled with principal component analysis can effectively acquire the optimal combination of cutting parameters and the proposed approach can be a useful tool to reduce the cutting force.

关键词： high-speed milling     grey relational analysis     principal component analysis     parameters optimization    

HTML PDF 收藏

Ball milling promoted direct liquefaction of lignocellulosic biomass in supercritical ethanol

Chunyan Yang, Xiaoliang Yuan, Xueting Wang, Kejing Wu, Yingying Liu, Changjun Liu, Houfang Lu, Bin Liang

《化学科学与工程前沿（英文）》 2020年 第14卷 第4期   页码 605-613 doi: 10.1007/s11705-019-1841-0

摘要： In the present work, ball milling was applied for the pretreatment of lignocellulose to obtain high conversion and bio-oil yield in supercritical ethanol. Ball milling substantially decreased the crystallinity and particle size of lignocellulose, thereby improving its accessibility in ethanol solvent. An increased bio-oil yield of 59.2% was obtained for the ball milled camphorwood sawdust at 300°C, compared with 39.6% for the original lignocellulose. Decreased crystallinity significantly benefited the conversion of the cellulose component from 60.8% to 91.7%, and decreased particle size was beneficial for the conversion of all components. The obtained bio-oil had a high phenolic content, as analyzed by gas chromatography-mass spectrometry. Methoxylation and retro-aldol condensation were observed during alcoholysis, and the reaction pathways of lignocellulose in supercritical ethanol were attributed to the action of free radicals.

关键词： ball milling     lignocellulose     supercritical ethanol     liquefaction     bio-oil    

HTML PDF 收藏

一种端到端语音合成中的高效解码自注意力网络 Research Article

赵伟1,2,许力1,2

《信息与电子工程前沿（英文）》 2022年 第23卷 第7期   页码 1127-1138 doi: 10.1631/FITEE.2100501

摘要： 自注意力网络由于其并行结构和强大的序列建模能力，被广泛应用于语音合成（TTS）领域。然而，当使用自回归解码方法进行端到端语音合成时，由于序列长度的二次复杂性，其推理速度相对较慢。当部署设备未配备图形处理器（GPU）时，该效率问题更加严重。为解决该问题，提出一种高效解码自注意力网络（EDSA）作为替代。通过一个动态规划解码过程，有效加速TTS模型推理，使其具有线性计算复杂度。基于普通话和英文数据集的实验结果表明，所提EDSA模型在中央处理器（CPU）和GPU上的推理速度分别提高720%和50%，而性能几乎相同。因此，在GPU资源有限的情况下，该方法可使此类模型的部署更加容易。此外，所提模型在域外语言处理上可能比基线Transformer TTS性能更好。

关键词： 高效解码；端到端；自注意力网络；语音合成    

HTML PDF 收藏

Coupling evaluation for material removal and thermal control on precision milling machine tools

《机械工程前沿（英文）》 2022年 第17卷 第1期   页码 12-12 doi: 10.1007/s11465-021-0668-9

摘要： Machine tools are one of the most representative machining systems in manufacturing. The energy consumption of machine tools has been a research hotspot and frontier for green low-carbon manufacturing. However, previous research merely regarded the material removal (MR) energy as useful energy consumption and ignored the useful energy consumed by thermal control (TC) for maintaining internal thermal stability and machining accuracy. In pursuit of energy-efficient, high-precision machining, more attention should be paid to the energy consumption of TC and the coupling relationship between MR and TC. Hence, the cutting energy efficiency model considering the coupling relationship is established based on the law of conservation of energy. An index of energy consumption ratio of TC is proposed to characterize its effect on total energy usage. Furthermore, the heat characteristics are analyzed, which can be adopted to represent machining accuracy. Experimental study indicates that TC is the main energy-consuming process of the precision milling machine tool, which overwhelms the energy consumption of MR. The forced cooling mode of TC results in a 7% reduction in cutting energy efficiency. Regression analysis shows that heat dissipation positively contributes 54.1% to machining accuracy, whereas heat generation negatively contributes 45.9%. This paper reveals the coupling effect of MR and TC on energy efficiency and machining accuracy. It can provide a foundation for energy-efficient, high-precision machining of machine tools.

关键词： machine tools     cutting energy efficiency     thermal stability     machining accuracy     coupling evaluation    

HTML PDF 收藏

Comparison on End-of-Life strategies of WEEE in China based on LCA

Bin Lu, Xiaolong Song, Jianxin Yang, Dong Yang

《环境科学与工程前沿（英文）》 2017年 第11卷 第5期 doi: 10.1007/s11783-017-0994-7

摘要： As the Electrical and Electronic Equipment (EEE) are upgraded more frequently in China, a large quantity of Waste Electrical and Electronic Equipment (WEEE) was and will be generated. It becomes an urgent issue to develop and adopt an effective End-of-Life (EoL) strategy for EEE in order to balance the resource recovery and environmental impacts. In an EoL strategy hierarchy for EEE, reuse strategy is usually deemed to be prior to materials recovery and other strategies. But in practice, the advantages and disadvantages of different strategies are always context-dependent. Therefore, main EoL strategies for EEE in China need to be evaluated in environment and resources aspects from the life cycle perspective. In this study, the obsolete refrigerator and Power Supply Unit (PSU) of desktop PC are both taken as the target products. Life Cycle Assessment (LCA) is applied to assess the environmental impacts of different EoL scenarios in China: Unit Reuse Scenario (URS), Component Reuse Scenario (CRS) and Materials Recovery Scenario (MRS). The LCA results show that the EoL strategies hierarchy is reasonable for the part of computer, but not necessarily suitable for obsolete refrigerators. When the policy makers promote or demote one EoL strategy especially reuse, it is necessary to take subsequent impacts into consideration.

关键词： End-of-Life     Waste electrical and electronic equipment     Life cycle assessment     Reuse    

HTML PDF 收藏

标题 作者 时间 类型 操作

3D finite element prediction of chip flow, burr formation, and cutting forces in micro end-milling of

A. DAVOUDINEJAD, P. PARENTI, M. ANNONI

期刊论文

Effect of Joule heating on electro-osmotic flow in a closed-end micro-channel with isothermal and convective

Liang ZHAO, Linhua LIU,

期刊论文

Mesoscale fabrication of a complex surface for integral impeller blades

Xibin WANG,Tianfeng ZHOU,Lijing XIE,Li JIAO,Zhibing LIU,Zhiqiang LIANG,Pei YAN

期刊论文

Energy field-assisted high-speed dry milling green machining technology for difficult-to-machine metal

期刊论文

Topology-independent end-to-end learning model for improving the voltage profile in microgrids-integrated

期刊论文

Fiber-reinforced composites in milling and grinding: machining bottlenecks and advanced strategies

期刊论文

Cutting Force Model for a Small-diameter Helical Milling Cutter

LI Xiwen, YANG Shuzi, YANG Mingjin, XIE Shouyong

期刊论文

Position-varying surface roughness prediction method considering compensated acceleration in milling

期刊论文

Mechanical behavior and semiempirical force model of aerospace aluminum alloy milling using nano biological

期刊论文

A hybrid deep learning model for robust prediction of the dimensional accuracy in precision milling of

期刊论文

Multi-objective optimization of cutting parameters in high-speed milling based on grey relational analysis

Tao FU, Jibin ZHAO, Weijun LIU

期刊论文

Ball milling promoted direct liquefaction of lignocellulosic biomass in supercritical ethanol

Chunyan Yang, Xiaoliang Yuan, Xueting Wang, Kejing Wu, Yingying Liu, Changjun Liu, Houfang Lu, Bin Liang

期刊论文

一种端到端语音合成中的高效解码自注意力网络

赵伟1,2,许力1,2

期刊论文

Coupling evaluation for material removal and thermal control on precision milling machine tools

期刊论文

Comparison on End-of-Life strategies of WEEE in China based on LCA

Bin Lu, Xiaolong Song, Jianxin Yang, Dong Yang

期刊论文