资源类型

期刊论文 828

年份

2024 1

2023 64

2022 61

2021 67

2020 50

2019 58

2018 50

2017 47

2016 38

2015 35

2014 38

2013 28

2012 33

2011 32

2010 32

2009 42

2008 41

2007 39

2006 9

2005 10

展开 ︾

关键词

COVID-19 2

三十烷醇 2

乳液 2

内禀尺度 2

冷凝水闪蒸 2

医院中子照射器I型堆 2

地球物理 2

数值模拟 2

无氢渗碳 2

最小二乘法 2

模型试验 2

水稻 2

混凝土 2

细水雾 2

&alpha 1

32 m箱梁 1

6G 1

ADV 1

ANSYS/LS-DYNA 1

展开 ︾

检索范围：

排序： 展示方式：

Thermal analysis of lubricated three-dimensional contact bodies considering interface roughness

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0672-8

摘要： Surface roughness and thermal action are of remarkable importance in the lubrication performance of mechanical components, especially in extreme conditions. However, available studies mainly focus on the full-film lubrication conditions without considering temperature rise and real 3D surface roughness due to the complexity of surface topography and temperature characteristics. Moreover, studies on the interfacial thermal behaviors of 3D rough surface lubricated contact in an extended range of working conditions remain limited. In this paper, a deterministic mixed thermal elastohydrodynamic lubrication model considering real 3D surface roughness and thermal effects is proposed. In this model, pressure and temperature are coupled with each other, the computation of elastic deformation is accelerated through the discrete convolution and fast Fourier transform method, the temperature field is calculated with the column sweeping technique, and the semi-system method is introduced to improve convergence and numerical stability under severe conditions. The model is validated by comparing its results with available published numerical and experimental results. The thermal behaviors of the contact interface are studied in a wide range of working conditions. The influences of surface roughness and thermal effect on lubrication performance are revealed. The results show that the proposed model can be used as a powerful analysis tool for lubrication performance and temperature prediction in various heavy-load, high-speed lubricated components over a wide range of lubrication conditions.

关键词： thermal elastohydrodynamic lubrication     surface roughness effect     thermal effect     temperature characteristics     severe conditions    

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

Calculated journal bearing lubrication of non-Newtonian medium with surface roughness effects

CHEN Hao-sheng, CHEN Da-rong, WANG Jia-dao, LI Yong-jian

《机械工程前沿（英文）》 2006年 第1卷 第3期   页码 270-275 doi: 10.1007/s11465-006-0028-9

摘要： To analyze the effects of non-Newtonian lubricants and surface roughness in journal bearing lubrication, a modified Reynolds equation is derived. In the equation, differential viscosity and the first normal stress function are defined to specify the rheological properties of non- Newtonian medium. Flow factors are used to specify the effect of surface roughness. The modified Reynolds equation is numerically calculated using super over relaxation method. Numerical results of the lubrication show that the differential viscosity is the principal non-Newtonian property affecting the lubrication, it is determined by the material parameters of the lubricant and is affected by the shearing rate. Under its effect, the load capacity of non-Newtonian lubricants is not always higher or lower than that of Newtonian lubricants . The effect of the first normal stress difference increases under the conditions of dynamic loading. Surface roughness shows an obvious effect on load capacity when it is greater than one-tenth of the film thickness, and the surface with longitudinal pattern affects the load capacity most. However, surface roughness has less effect on lubrication results than lubricants non-Newtonian property.

关键词： rheological     dynamic     lubrication     roughness     shearing    

HTML PDF 收藏

Tribological study on the surface modification of metal-on-polymer bioimplants

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0682-6

摘要： The tribological performance of artificial joints is regarded as the main factor of the lifespan of implanted prostheses. The relationship between surface roughness and coefficient of friction (COF) under dry and lubricated conditions is studied. Results show that under dry test, friction coefficient is not reduced all the time with a decrease in surface roughness. On the contrary, a threshold of roughness value is observed, and frictional force increases again below this value. This critical value lies between 40 and 100 nm in Sa (roughness). This phenomenon is due to the transfer of friction mechanisms from abrasion to adhesion. Under wet test, COF always decreases with reduction in surface roughness. This result is mainly attributed to the existence of a thin layer of lubricant film that prevents the intimate contact of two articulating surfaces, thus greatly alleviating adhesion friction. Furthermore, surface texturing technology is successful in improving the corresponding tribological performance by decreasing friction force and mitigating surface deterioration. The even-distribution mode of texturing patterns is most suitable for artificial joints. By obtaining the optimal surface roughness and applying texturing technology, the tribological performance of polymer-based bioimplants can be greatly enhanced.

关键词： artificial joints     surface roughness     friction     surface texturing    

HTML PDF 收藏

Review on mechanism and process of surface polishing using lasers

Arun KRISHNAN, Fengzhou FANG

《机械工程前沿（英文）》 2019年 第14卷 第3期   页码 299-319 doi: 10.1007/s11465-019-0535-0

摘要： Laser polishing is a technology of smoothening the surface of various materials with highly intense laser beams. When these beams impact on the material surface to be polished, the surface starts to be melted due to the high temperature. The melted material is then relocated from the ‘peaks to valleys’ under the multidirectional action of surface tension. By varying the process parameters such as beam intensity, energy density, spot diameter, and feed rate, different rates of surface roughness can be achieved. High precision polishing of surfaces can be done using laser process. Currently, laser polishing has extended its applications from photonics to molds as well as bio-medical sectors. Conventional polishing techniques have many drawbacks such as less capability of polishing freeform surfaces, environmental pollution, long processing time, and health hazards for the operators. Laser polishing on the other hand eliminates all the mentioned drawbacks and comes as a promising technology that can be relied for smoothening of initial topography of the surfaces irrespective of the complexity of the surface. Majority of the researchers performed laser polishing on materials such as steel, titanium, and its alloys because of its low cost and reliability. This article gives a detailed overview of the laser polishing mechanism by explaining various process parameters briefly to get a better understanding about the entire polishing process. The advantages and applications are also explained clearly to have a good knowledge about the importance of laser polishing in the future.

关键词： laser polishing     surface roughness     process parameters     mechanism    

HTML PDF 收藏

Ultrasonic assisted EDM: Effect of the workpiece vibration in the machining characteristics of FW4 Welded

Mohammadreza SHABGARD, Hamed KAKOLVAND, Mirsadegh SEYEDZAVVAR, Ramin Mohammadpour SHOTORBANI

《机械工程前沿（英文）》 2011年 第6卷 第4期   页码 419-428 doi: 10.1007/s11465-011-0246-7

摘要：

This paper presents the results of experimental studies carried out to conduct a comprehensive investigation on the influence of ultrasonic vibration of workpiece on the characteristics of Electrical Discharge Machining (EDM) process of FW4 Welding Metal in comparison with the conventional EDM process. The studied process characteristics included the material removal rate (MRR), tool wear ratio (TWR), and surface roughness (Ra and Rmax) of the workpiece after the EDM and ultrasonic assisted EDM (US-EDM) processes. The experiments performed under the designed full factorial procedure and the considered EDM input parameters included pulse on-time and pulse current. The experimental results show that in short pulse on-times, material removal rate in the US-EDM process is approximately quadruple than that of the EDM process. On the contrary, in the long pulse on-times, ultrasonic vibration of work??piece leads to the reduction in the MRR. On the other hand, in short pulse on-times, the TWR in the US-EDM process is lower than that of in the EDM process, and this condition reverses with increase in the pulse on-time. Furthermore, the surface roughness of the workpiece machined by EDM process is slightly lower than that of applied to the US-EDM process.

关键词： electrical discharge machining (EDM)     material removal rate (MRR)     tool wear ratio (TWR)     surface roughness    

HTML PDF 收藏

Effects of process parameters on surface roughness in abrasive waterjet cutting of aluminium

M. CHITHIRAI PON SELVAN, N. MOHANA SUNDARA RAJU, H. K. SACHIDANANDA

《机械工程前沿（英文）》 2012年 第7卷 第4期   页码 439-444 doi: 10.1007/s11465-012-0337-0

摘要：

Abrasive waterjet cutting is a novel machining process capable of processing wide range of hard-to-cut materials. Surface roughness of machined parts is one of the major machining characteristics that play an important role in determining the quality of engineering components. This paper shows the influence of process parameters on surface roughness (Ra) which is an important cutting performance measure in abrasive waterjet cutting of aluminium. Taguchi’s design of experiments was carried out in order to collect surface roughness values. Experiments were conducted in varying water pressure, nozzle traverse speed, abrasive mass flow rate and standoff distance for cutting aluminium using abrasive waterjet cutting process. The effects of these parameters on surface roughness have been studied based on the experimental results.

关键词： abrasive waterjet     aluminium     garnet     water pressure     mass flow rate     traverse speed     standoff distance    

HTML PDF 收藏

Radiative properties of materials with surface scattering or volume scattering: A review

Qunzhi ZHU, Hyunjin LEE, Zhuomin M. HANG

《能源前沿（英文）》 2009年 第3卷 第1期   页码 60-79 doi: 10.1007/s11708-009-0011-3

摘要： Radiative properties of rough surfaces, particulate media and porous materials are important in thermal engineerit transfer between surfaces and volume elements in participating media, as well as for accurate radiometric temperature measurements. In this paper, recent research on scattering of thermal radiation by rough surfaces, fibrous insulation, soot, aerogel, biological materials, and polytetrafluoroethylene (PTFE) was reviewed. Both theoretical modeling and experimental investigation are discussed. Rigorous solutions and approximation methods for surface scattering and volume scattering are described. The approach of using measured surface roughness statistics in Monte Carlo simulations to predict radiative properties of rough surfaces is emphasized. The effects of various parameters on the radiative properties of particulate media and porous materials are summarized.

关键词： aerogel     fiber     particle scattering     radiative properties     soot     surface roughness    

HTML PDF 收藏

零件加工质量（尺寸和表面粗糙度）在线检测技术研究

陈爱弟,王信义

《中国工程科学》 2000年 第2卷 第12期   页码 73-77

摘要：

文章研究零件加工质量在线检测的方法和关键技术。在分析在线检测工件尺寸和表面粗糙度检测方法及特点的基础上，建立检测工件尺寸的神经网络和检测表面粗糙度的模糊神经网络，并且建立了零件加工质量在线检测系统。实验表明该方法能够正确地实时检测工件的尺寸变化和工件表面粗糙度。

关键词： 在线检测     神经网络     模糊神经网络     尺寸精度     表面粗糙度    

HTML PDF 收藏

Effects of taping on grinding quality of silicon wafers in backgrinding

Zhigang DONG, Qian ZHANG, Haijun LIU, Renke KANG, Shang GAO

《机械工程前沿（英文）》 2021年 第16卷 第3期   页码 559-569 doi: 10.1007/s11465-020-0624-0

摘要： Taping is often used to protect patterned wafers and reduce fragmentation during backgrinding of silicon wafers. Grinding experiments using coarse and fine resin-bond diamond grinding wheels were performed on silicon wafers with tapes of different thicknesses to investigate the effects of taping on peak-to-valley (PV), surface roughness, and subsurface damage of silicon wafers after grinding. Results showed that taping in backgrinding could provide effective protection for ground wafers from breakage. However, the PV value, surface roughness, and subsurface damage of silicon wafers with taping deteriorated compared with those without taping although the deterioration extents were very limited. The PV value of silicon wafers with taping decreased with increasing mesh size of the grinding wheel and the final thickness. The surface roughness and subsurface damage of silicon wafers with taping decreased with increasing mesh size of grinding wheel but was not affected by removal thickness. We hope the experimental finding could help fully understand the role of taping in backgrinding.

关键词： taping     silicon wafer     backgrinding     subsurface damage     surface roughness    

HTML PDF 收藏

Sub-nanometer finishing of polycrystalline tin by inductively coupled plasma-assisted cutting

《机械工程前沿（英文）》 2023年 第18卷 第3期 doi: 10.1007/s11465-023-0751-5

摘要： Polycrystalline tin is an ideal excitation material for extreme ultraviolet light sources. However, the existence of grain boundary (GB) limits the surface roughness of polycrystalline tin after single-point diamond turning (SPDT). In this work, a novel method termed inductively coupled plasma (ICP)-assisted cutting was developed for the sub-nanometer finishing of polycrystalline tin. The relationship between ICP power, processing time, and modification depth was established by thermodynamic simulation, and the fitted heat transfer coefficient of polycrystalline tin was 540 W/(m2·K). The effects of large-thermal-gradient ICP treatment on the microstructure of polycrystalline tin were studied. After 0.9 kW ICP processing for 3.0 s, corresponding to the temperature gradient of 0.30 K/µm, the grain size of polycrystalline tin was expanded from a size of approximately 20–80 μm to a millimeter scale. The Taguchi method was used to investigate the effects of rotational speed, depth of cut, and feed rate on SPDT. Experiments conducted based on the ICP system indicated that the plasma-assisted cutting method promoted the reduction of the influence of GB steps on the finishing of polycrystalline tin, thereby achieving a surface finish from 8.53 to 0.80 nm in Sa. The results of residual stress release demonstrated that the residual stress of plasma-assisted turning processing after 504 h stress release was 10.7 MPa, while that of the turning process without the ICP treatment was 41.6 MPa.

关键词： plasma-assisted cutting     polycrystalline tin     single-point diamond turning     surface roughness    

HTML PDF 收藏

Experimental study of surface integrity and fatigue life in the face milling of Inconel 718

Xiangyu WANG, Chuanzhen HUANG, Bin ZOU, Guoliang LIU, Hongtao ZHU, Jun WANG

《机械工程前沿（英文）》 2018年 第13卷 第2期   页码 243-250 doi: 10.1007/s11465-018-0479-9

摘要：

The Inconel 718 alloy is widely used in the aerospace and power industries. The machining-induced surface integrity and fatigue life of this material are important factors for consideration due to high reliability and safety requirements. In this work, the milling of Inconel 718 was conducted at different cutting speeds and feed rates. Surface integrity and fatigue life were measured directly. The effects of cutting speed and feed rate on surface integrity and their further influences on fatigue life were analyzed. Within the chosen parameter range, the cutting speed barely affected the surface roughness, whereas the feed rate increased the surface roughness through the ideal residual height. The surface hardness increased as the cutting speed and feed rate increased. Tensile residual stress was observed on the machined surface, which showed improvement with the increasing feed rate. The cutting speed was not an influencing factor on fatigue life, but the feed rate affected fatigue life through the surface roughness. The high surface roughness resulting from the high feed rate could result in a high stress concentration factor and lead to a low fatigue life.

关键词： roughness     hardness     residual stress     microstructure     fatigue life    

HTML PDF 收藏

东太湖湖泊水面萎缩的状况及影响

魏清福

《中国工程科学》 2010年 第12卷 第6期   页码 123-126

摘要：

东太湖是长江中下游地区典型的草型湖泊，是太湖的浅水湖湾和主要出水通道，也是上海市、浙江省杭嘉湖城镇供水取水口的主要来水水源和江苏省吴江市的供水水源地，具有防洪、供水、水生态环境保护和水产养殖等多种功能。近半个世纪以来在自然和人为因素的长期作用下，东太湖水面不断缩小，湖泊形态和水生态环境遭到严重破坏，湖泊衰亡进程加快，其行洪、供水、水生态环境保护等湖泊良好的服务功能无法正常发挥。回顾东太湖的演变历程，初步探讨了东太湖水面萎缩的现状及对湖泊功能的影响，并针对目前规划采取的治理措施提出了几点看法，供湖泊治理参考。

关键词： 东太湖     水面     萎缩     影响     关键技术    

HTML PDF 收藏

Environmental dispersivity in free-water-surface-effect dominated wetland: multi-scale analysis

Zi WU, Zhi LI, Li ZENG, Ling SHAO, Hansong TANG, Qing YANG, Guoqian CHEN

《环境科学与工程前沿（英文）》 2011年 第5卷 第4期   页码 597-603 doi: 10.1007/s11783-011-0311-9

摘要： Distinct from the case with width-dominated shallow wetland flows, the longitudinal evolution of contaminant concentration in the most-typical pattern of wetland as dominated by free-water-surface-effect is characterized by a multi-scale analysis in the present study. An environmental dispersion model for the evolution of the mean concentration is deduced as an extension of Taylor's classical formulation by Mei’s multi-scale analysis. Corresponding environmental dispersivity is found identical to that determined by the method of concentration moments.

关键词： free-surface wetland     environmental dispersion     multi-scale analysis    

HTML PDF 收藏

Optimization of WEDM process of pure titanium with multiple performance characteristics using Taguchi’s DOE approach and utility concept

Rupesh CHALISGAONKAR, Jatinder KUMAR

《机械工程前沿（英文）》 2013年 第8卷 第2期   页码 201-214 doi: 10.1007/s11465-013-0256-8

摘要：

This paper describes the development of multi response optimization technique using utility method to predict and select the optimal setting of machining parameters in wire electro-discharge machining (WEDM) process. The experimental studies in WEDM process were conducted under varying experimental conditions of process parameters, such as pulse on time(Ton), pulse off time(Toff), peak current (IP), wire feed (WF), wire tension (WT) and servo voltage (SV) using pure titanium as work material. Experiments were planned using Taguchi’s L27 orthogonal array. Multi response optimization was performed for both cutting speed (CS) and surface roughness (SR) using utility concept to find out the optimal process parameter setting. The level of significance of the machining parameters for their effect on the CS and SR was determined by using analysis of variance (ANOVA). Finally, confirmation experiment was performed to validate the effectiveness of the proposed optimal condition.

关键词： wire electro-discharge machining (WEDM)     Taguchi method     analysis of variance (ANOVA)     utility concept     cutting speed (CS)     surface roughness (SR)    

HTML PDF 收藏

标题 作者 时间 类型 操作

Thermal analysis of lubricated three-dimensional contact bodies considering interface roughness

期刊论文

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

期刊论文

Calculated journal bearing lubrication of non-Newtonian medium with surface roughness effects

CHEN Hao-sheng, CHEN Da-rong, WANG Jia-dao, LI Yong-jian

期刊论文

Tribological study on the surface modification of metal-on-polymer bioimplants

期刊论文

Review on mechanism and process of surface polishing using lasers

Arun KRISHNAN, Fengzhou FANG

期刊论文

Ultrasonic assisted EDM: Effect of the workpiece vibration in the machining characteristics of FW4 Welded

Mohammadreza SHABGARD, Hamed KAKOLVAND, Mirsadegh SEYEDZAVVAR, Ramin Mohammadpour SHOTORBANI

期刊论文

Effects of process parameters on surface roughness in abrasive waterjet cutting of aluminium

M. CHITHIRAI PON SELVAN, N. MOHANA SUNDARA RAJU, H. K. SACHIDANANDA

期刊论文

Radiative properties of materials with surface scattering or volume scattering: A review

Qunzhi ZHU, Hyunjin LEE, Zhuomin M. HANG

期刊论文

零件加工质量（尺寸和表面粗糙度）在线检测技术研究

陈爱弟,王信义

期刊论文

Effects of taping on grinding quality of silicon wafers in backgrinding

Zhigang DONG, Qian ZHANG, Haijun LIU, Renke KANG, Shang GAO

期刊论文

Sub-nanometer finishing of polycrystalline tin by inductively coupled plasma-assisted cutting

期刊论文

Experimental study of surface integrity and fatigue life in the face milling of Inconel 718

Xiangyu WANG, Chuanzhen HUANG, Bin ZOU, Guoliang LIU, Hongtao ZHU, Jun WANG

期刊论文

东太湖湖泊水面萎缩的状况及影响

魏清福

期刊论文

Environmental dispersivity in free-water-surface-effect dominated wetland: multi-scale analysis

Zi WU, Zhi LI, Li ZENG, Ling SHAO, Hansong TANG, Qing YANG, Guoqian CHEN

期刊论文

Optimization of WEDM process of pure titanium with multiple performance characteristics using Taguchi’s DOE approach and utility concept

Rupesh CHALISGAONKAR, Jatinder KUMAR

期刊论文