期刊文献+
共找到27,449篇文章
< 1 2 250 >
每页显示 20 50 100
Active control of friction by transverse oscillations
1
作者 J.BENAD K.NAKANO +1 位作者 V.L.POPOV M.POPOV 《摩擦(英文版)》 CSCD 2019年第1期74-85,共12页
The present paper is devoted to a theoretical analysis of sliding friction under the influence of in-plane oscillations perpendicular to the sliding direction.Contrary to previous studies of this mode of active contro... The present paper is devoted to a theoretical analysis of sliding friction under the influence of in-plane oscillations perpendicular to the sliding direction.Contrary to previous studies of this mode of active control of friction,we consider the influence of the stiffness of the tribological contact in detail and show that the contact stiffness plays a central role for small oscillation amplitudes.In the present paper we consider the case of a displacement-controlled system,where the contact stiffness is small compared to the stiffness of the measuring system.It is shown that in this case the macroscopic coefficient of friction is a function of two dimensionless parameters a dimensionless sliding velocity and dimensionless oscillation amplitude.In the limit of very large oscillation amplitudes,known solutions previously reported in the literature are reproduced.The region of small amplitudes is described for the first time in this paper. 展开更多
关键词 SLIDING FRICTION IN-PLANE OSCILLATION contact STIFFNESS COEFFICIENT of FRICTION active control of FRICTION
基于DISlab系统的摩擦力教学测量仪的设计与研究 预览
2
作者 王一超 徐佳林 +2 位作者 郑思怡 张译丹 呼格吉乐 《科技创新与应用》 2019年第16期27-28,共2页
在我们的生活中,摩擦力处处存在而且起着十分重要的作用。在实际的教学过程中,摩擦力的分析一直是教学的难点,对于学生来说,摩擦力的大小和方向只能借助作用效果来分析,会显的十分抽象,不够直观,基于此问题的思考,结合DISlab朗威实验系... 在我们的生活中,摩擦力处处存在而且起着十分重要的作用。在实际的教学过程中,摩擦力的分析一直是教学的难点,对于学生来说,摩擦力的大小和方向只能借助作用效果来分析,会显的十分抽象,不够直观,基于此问题的思考,结合DISlab朗威实验系统制作出了一款摩擦力的测量仪,可以较为直观的展示摩擦力的方向和大小,有助于学生理解和学习摩擦力的相关知识。 展开更多
关键词 摩擦力 滑动摩擦 力的传递 最大静摩擦力 运动情况 DIS实验系统
在线阅读 下载PDF
石墨烯与MoS2纳米颗粒对PAO40摩擦学性能的影响研究 预览
3
作者 金旭阳 杜洋 +1 位作者 张明宇 王静 《青岛理工大学学报》 CAS 2019年第4期104-108,共5页
采用四球摩擦磨损试验机考察了石墨烯与MoS2纳米颗粒添加剂对合成油PAO40的抗磨减摩性能的影响.试验后通过磨斑显微镜观察磨斑形状并用Origin软件处理了摩擦系数和磨斑的表征直径.试验结果显示:只有在特定工况条件下,特定浓度的石墨烯和... 采用四球摩擦磨损试验机考察了石墨烯与MoS2纳米颗粒添加剂对合成油PAO40的抗磨减摩性能的影响.试验后通过磨斑显微镜观察磨斑形状并用Origin软件处理了摩擦系数和磨斑的表征直径.试验结果显示:只有在特定工况条件下,特定浓度的石墨烯和MoS2纳米颗粒添加剂才具有抗磨减摩效果.整体上讲,MoS2纳米颗粒添加剂的抗磨减摩效果要优于石墨烯. 展开更多
关键词 摩擦 四球摩擦磨损试验机 石墨烯 MoS 2 抗磨 减摩
在线阅读 下载PDF
收获期谷子叶片摩擦特性的试验研究 预览
4
作者 张宁 李红波 +2 位作者 张燕青 崔清亮 孙青芳 《农机化研究》 北大核心 2019年第6期154-161,共8页
为了探明谷子叶片的摩擦特性,降低其对谷子联合收获机割台损失的影响,采用自制摩擦测试装置,联合Instron5544型电子万能试验机,选定谷子张杂10号、晋谷21号和沁州黄等3个品种,分别测定了叶片之间及叶片与不同金属材料接触时的摩擦特性... 为了探明谷子叶片的摩擦特性,降低其对谷子联合收获机割台损失的影响,采用自制摩擦测试装置,联合Instron5544型电子万能试验机,选定谷子张杂10号、晋谷21号和沁州黄等3个品种,分别测定了叶片之间及叶片与不同金属材料接触时的摩擦特性参数。分析了叶片不同方向(纵向和横向)、不同表面(上表面和下表面)、不同倒刺方向(顺纹和逆纹)及不同金属薄板(钢板、铝板、铁板)等因素对叶片摩擦特性的影响规律。试验结果表明:叶片与叶片摩擦时,张杂10号、晋谷21号、沁州黄的静摩擦因数和滑动摩擦因数值范围分别为0.3953~0.9665/0.3695~0.9565、0.3657~0.9467/0.3556~0.8863、0.3570~0.9420/0.3338~0.9088;叶片的方向及倒刺方向两因素对其影响极显著(P<0.01),叶片在横向及逆着倒刺方向时,摩擦因数值较大。叶片与不同金属材料接触时,张杂10号、晋谷21号、沁州黄叶片与不同金属材料板接触时静摩擦因数值和滑动摩擦因数值范围分别为0.2800~0.5865/0.2546~0.4595、0.2625~0.6080/0.2265~0.4595、0.2805~0.4660/0.2676~0.4318;其与铁板的摩擦因数值最高,钢板与铝板次之且无显著差别。研究结果可为谷子收获机械的研制与设计提供一定的技术参数和理论依据。 展开更多
关键词 谷子叶片 摩擦 静摩擦因数 滑动摩擦因数
在线阅读 下载PDF
Principles and application of RES welding technology 预览
5
作者 韩立军 于立建 +1 位作者 张更伟 钟丽慧 《中国焊接:英文版》 EI CAS 2019年第2期50-55,共6页
Friction element welding technology is rich of flow drill screws combined with friction welding technology and is developed for the hot-forming steel plate and aluminum alloy welding of car body-in-white.In this paper... Friction element welding technology is rich of flow drill screws combined with friction welding technology and is developed for the hot-forming steel plate and aluminum alloy welding of car body-in-white.In this paper,the principle of RES welding technology,equipment,technical characteristics,application condition and welding parameters are analyzed systematically.Moreover,the changing laws of welding parameters and welded joint quality control standards are described,which provides the necessary technical support for safety and light-weight car body design requirements.This study has high practical application value,and enriches the automobile body joining technology. 展开更多
关键词 friction element welding flow drill screws friction welding aluminum alloy hot-forming steel
在线阅读 下载PDF
The Island Rule with lateral and bottom friction 预览
6
作者 Yanzhao Yang Zexun Wei +2 位作者 Guanlin Wang Zhan Lian Liwei Wang 《海洋学报:英文版》 SCIE CAS CSCD 2019年第4期146-153,共8页
The Island Rule,derived from the Sverdrup theory,is widely used to estimate and analyze water transport through a strait.Previous studies presented single-or multi-island rules with either lateral or bottom friction.I... The Island Rule,derived from the Sverdrup theory,is widely used to estimate and analyze water transport through a strait.Previous studies presented single-or multi-island rules with either lateral or bottom friction.In this paper,an analytical model of wind-driven circulation is assumed based on linear dynamics.Considering both lateral and bottom friction,the analytic solutions of the transport streamfunction around the islands are derived and the volume transport through the channel is presented.The results are similar to those of Wajsowicz,but the frictional constants represent different values.The analytic solution shows that the relationship between the lateral frictional and bottom frictional dissipation is complex in terms of the frictional constants.To understand the interaction between the two friction types,lateral and bottom friction values were randomly chosen on a barotropic beta plane.The result shows an approximately linear relationship between the lateral and bottom friction in consisting of the combined frictional constants.We studied the effect of the channel width on the transport through the channel.The results show that the friction enhances the flow under some widths,which is similar to the flow behavior when only the lateral friction is considered.We also compared the transport through the channel at different depths and founded that the deeper the water,the smaller the transport reduction ratio when the horizontal eddy viscosity coefficient and the bottom drag coefficient remained constants.To further present the combined role of lateral frictional and bottom frictional dissipation,we compared our model with the model of Wajsowicz for two islands,where only the lateral or bottom friction were considered,with different channel widths.The results showed that the effect of the lateral friction is greater than the bottom friction when the channel is narrow,especially in the Munk boundary layer thickness.When the channel is much wider than the Munk boundary layer thickness,the role of the bottom 展开更多
关键词 ISLAND RULE LATERAL FRICTION BOTTOM FRICTION TRANSPORT streamfunction
在线阅读 下载PDF
微坑型微织构硬质合金表面对木材摩擦特性的影响 预览
7
作者 李伟光 张占宽 《林业科学》 EI CAS CSCD 北大核心 2019年第4期136-143,共8页
【目的】探讨木材含水率、木材切面和纤维方向以及运动速度等因素对木材表面摩擦系数的影响规律,为设计更加合理的木材切削刀具表面织构形式提供参考和指导。【方法】以水曲柳和樟子松为研究对象,在具有不同微坑直径硬质合金表面条件下... 【目的】探讨木材含水率、木材切面和纤维方向以及运动速度等因素对木材表面摩擦系数的影响规律,为设计更加合理的木材切削刀具表面织构形式提供参考和指导。【方法】以水曲柳和樟子松为研究对象,在具有不同微坑直径硬质合金表面条件下,研究木材含水率、木材切面和纤维方向以及运动速度等因素对木材表面摩擦系数的影响。【结果】与无微坑表面相比,当微坑直径为60μm、含水率为67%±3%时,在水曲柳表面产生的摩擦系数由0.151降低到0.091,降幅为39.7%,在樟子松表面产生的摩擦系数由0.241降低到0.164,降幅为32.0%。木材径切面上纤维方向差异对表面摩擦系数的影响不大,但在横切面上,微坑直径越小,其表现出的摩擦系数越高。摩擦过程中运动速度对表面摩擦系数的影响与木材中的水分有较大关系,当含水率处于生材状态时,表面摩擦系数随运动速度增大而降低,且微坑型结构表面产生的摩擦系数降幅明显高于无微坑表面,无微坑表面产生的摩擦系数由0.160降低到0.134,降幅为16.3%,微坑直径为60μm时的摩擦系数由0.124降低到0.071,降幅为42.7%。【结论】木材含水率状态对微坑型表面微织构与木材之间的摩擦系数影响较大,木材中自由水的存在有利于降低硬质合金与木材表面之间的摩擦系数。微织构直径越小,其接触角平均变化率越大,表面铺展速度越大,越有利于改善木材/硬质合金摩擦副的状态,使表面间的摩擦系数减小。 展开更多
关键词 木材 切削 摩擦 摩擦系数 微织构
在线阅读 下载PDF
塔磨机橡胶磁性衬板的吸附力研究
8
作者 刘万华 于忠淇 赵骞 《矿山机械》 2019年第4期31-34,共4页
对塔磨机橡胶磁性衬板的磁吸附力进行了研究,通过悬挂重物法,测量出不同材质的磨球在衬板表面的吸附力,再用Ansoft有限元软件,模拟分析了衬板表面磁感应强度分布规律,并计算出衬板与筒体之间的摩擦因数为0.47,最后拟合出橡胶磁性衬板和... 对塔磨机橡胶磁性衬板的磁吸附力进行了研究,通过悬挂重物法,测量出不同材质的磨球在衬板表面的吸附力,再用Ansoft有限元软件,模拟分析了衬板表面磁感应强度分布规律,并计算出衬板与筒体之间的摩擦因数为0.47,最后拟合出橡胶磁性衬板和筒体之间的吸附力与磁极厚度的关系。该研究对大型塔磨机在磁铁矿中的应用具有重要的参考和借鉴价值。 展开更多
关键词 塔磨机 橡胶磁性衬板 吸附力 摩擦力 摩擦因数
Experimental study on the tribo-chemical smoothening process between self-mated silicon carbide in a water-lubricated surfacecontact reciprocating test
9
作者 Le JIN Herbert SCHEERER +2 位作者 Georg ANDERSOHN Matthias OECHSNER Dieter HELLMANN 《摩擦(英文版)》 CSCD 2019年第2期181-191,共11页
Silicon carbide(SiC) can be tribo-chemically smoothened during a self-mated sliding procedure in the aqueous environment.As well reported in the point-contact tests,this smoothening process works well due to the abund... Silicon carbide(SiC) can be tribo-chemically smoothened during a self-mated sliding procedure in the aqueous environment.As well reported in the point-contact tests,this smoothening process works well due to the abundant water as oxidant.After this smoothening process,the tribo-surface is well polished,a closely mated tribo-gap naturally forms,and an ultra-low friction state is built.However,water in the tribo-gap could be insufficient in industrial applications,e.g.,the seal gap in mechanical seals.In this study,the tribo-chemical smoothening behavior in such environment was researched.A surface-contact reciprocating test was used to simulate the aqueous environment where water was insufficient.After tests,compared to the published results from the point-contact tests,the same ultra-low friction state was achieved.A part of the tribo-surface was tribo-chemically smoothened.The obtained smoothened surface microstructure was consistent with the published information.Meanwhile,severe abrasive wear occurred.A porous oxygen-rich layer was found existing beneath the abrasion-induced grooves,in which numerous smashed wear debris adhered on the worn surfaces.We concluded that the shortage of water initiated the severe abrasion,meanwhile the generated wear debris aggravated the wear condition.This understanding is instructive for developing new methods to avoid the severe abrasion in the same water insufficient environment. 展开更多
关键词 silicon CARBIDE surface-contact SLIDING FRICTION tribo-chemical smoothening ABRASION ultra-low FRICTION mechanical seal
Friction
10
《摩擦(英文版)》 CSCD 2019年第5期497-499,共3页
Aims and Scope Friction is a peer-reviewed international journal for the publication of theoretical and experimental research works related to the friction,lubrication and wear.Original,high quality research papers an... Aims and Scope Friction is a peer-reviewed international journal for the publication of theoretical and experimental research works related to the friction,lubrication and wear.Original,high quality research papers and review articles on all aspects of tribology are welcome,including,but are not limited to,a variety of topics,such as:Friction:Origin of friction,Friction theories,New phenomena of friction,Nano-friction,Ultra-low friction,Molecular friction,Ultra‐high friction,Friction at high speed,Friction at high temperature or low temperature,Friction at solid/liquid interfaces,Bio‐friction,Adhesion,etc. 展开更多
关键词 FRICTION AIMS SCOPE FRICTION
织造中碳纤维束间的摩擦磨损试验模拟 预览
11
作者 杨洁 吴宁 +3 位作者 李帅 解锡明 焦亚男 陈利 《摩擦学学报》 EI CAS CSCD 北大核心 2019年第1期90-98,共9页
织造过程中碳纤维束的摩擦磨损会导致成型后复合材料制件的机械性能下降.采用自制的试验装置模拟织造过程中经纬纱线间的相互作用,研究了法向负载、预加张力和摩擦速率对碳纤维束摩擦磨损行为的影响.结果表明:碳纤维束的摩擦系数随着法... 织造过程中碳纤维束的摩擦磨损会导致成型后复合材料制件的机械性能下降.采用自制的试验装置模拟织造过程中经纬纱线间的相互作用,研究了法向负载、预加张力和摩擦速率对碳纤维束摩擦磨损行为的影响.结果表明:碳纤维束的摩擦系数随着法向负载的增加而减小,其磨损程度随着法向负载的增加而增大,相对应的碳纤维束拉伸断裂强力也逐渐下降;碳纤维束的摩擦力和摩擦系数因实际摩擦接触面积的变化随预加张力的增加而增大;摩擦速率的增加几乎不影响碳纤维束的摩擦力和摩擦系数,但延长了其测试值达到稳定所需的周期数. 展开更多
关键词 碳纤维 织造 摩擦 磨损 法向负载 预加张力 摩擦速率
在线阅读 免费下载
Cr2AlC含量对铜基复合材料摩擦磨损性能的影响
12
作者 吴辉 郭彪 +3 位作者 李强 敖进清 刘胜明 鲁云 《粉末冶金技术》 CAS CSCD 北大核心 2019年第3期184-190,共7页
采用冷压-烧结方法制备了含质量分数0%、5%、10%、15%Cr2AlC的铜基复合材料,利用光学显微镜、扫描电子显微镜及能谱仪观察并分析复合材料微观组织和微区成分,使用HVS-1000型显微硬度计和M-2000型摩擦磨损试验机测试复合材料的硬度和摩... 采用冷压-烧结方法制备了含质量分数0%、5%、10%、15%Cr2AlC的铜基复合材料,利用光学显微镜、扫描电子显微镜及能谱仪观察并分析复合材料微观组织和微区成分,使用HVS-1000型显微硬度计和M-2000型摩擦磨损试验机测试复合材料的硬度和摩擦磨损性能,分析Cr2AlC质量分数对复合材料硬度、摩擦性能和磨损机理的影响。结果表明:含Cr2AlC铜基复合材料的相对密度为0.8,Cr2AlC均匀分布在铜基体上,有效提高了复合材料的硬度;随Cr2AlC质量分数增加,复合材料摩擦系数先升高后降低,磨损量先降低后回升,当Cr2AlC质量分数为10%时,复合材料的摩擦系数最大,磨损量最低,耐磨性能最佳;未添加Cr2AlC的纯铜材料磨损机理以黏滑为主,含Cr2AlC铜基复合材料的磨损机理是犁削磨损、剥层磨损和氧化磨损三者的结合。 展开更多
关键词 铜基复合材料 硬度 摩擦 磨损 摩擦系数
The measure of friction angles for different types of granular material
13
作者 DEGANUTTI Andrea Maria TECCA Pia Rosella GENEVOIS Rinaldo 《山地科学学报:英文版》 SCIE CSCD 2019年第4期769-777,共9页
The aim of this research is to deepen the knowledge of the role of friction on the dynamics of granular media;in particular the friction angle is taken into consideration as the physical parameter that drives stabilit... The aim of this research is to deepen the knowledge of the role of friction on the dynamics of granular media;in particular the friction angle is taken into consideration as the physical parameter that drives stability, motion and deposition of a set of grains of any nature and size. The idea behind this work is a question: is the friction angle really that fundamental and obvious physical parameter which rules stability and motion of granular media as it seems from most works which deal with particle dynamics? The experimental study tries to answer this question with a series of laboratory tests, in which different natural and artificial granular materials have been investigated in dry condition by means of a tilting flume. The characteristic friction angles, both in deposition(repose) and stability limit(critical) conditions, were measured and checked against size, shape, density and roughness of the considered granular material. The flume tests have been preferred to 'classical' geotechnical apparatuses(e.g. shear box) since the flume experimental conditions appear closer to the natural ones of many situations of slope stability interest(e.g. a scree slope). The results reveal that characteristic friction angles depend on size and shape of grains while mixtures of granules of different size show some sorting mechanism with less clear behaviour. 展开更多
关键词 RHEOLOGY GRANULAR material FRICTION angle DEPOSITION PROCESS YIELDING PROCESS
The properties of N-doped diamond-like carbon films prepared by helicon wave plasma chemical vapor deposition
14
作者 陈佳丽 季佩宇 +2 位作者 金成刚 诸葛兰剑 吴雪梅 《等离子体科学与技术:英文版》 SCIE EI CAS CSCD 2019年第2期78-82,共5页
In this paper, N-doped diamond-like carbon(DLC) films were deposited on silicon substrates by using helicon wave plasma chemical vapor deposition(HWP-CVD) with the Ar/CH4/N2 mixed gas. The surface morphology, structur... In this paper, N-doped diamond-like carbon(DLC) films were deposited on silicon substrates by using helicon wave plasma chemical vapor deposition(HWP-CVD) with the Ar/CH4/N2 mixed gas. The surface morphology, structural and mechanical properties of the N-doped DLC films were investigated in detail by scanning electron microscopy(SEM), x-ray photoelectron spectroscopy(XPS), Raman spectra, and atomic force microscopy(AFM). It can be observed from SEM images that surface morphology of the films become compact and uniform due to the incorporation of N. The maximum of the deposition rate of the films is 143 nm min-1, which is related to the high plasma density. The results of XPS show that the N incorporates in the films and the C-C sp3 bond content increases firstly up to the maximum(20%) at 10 sccm of N2 flow rate, and then decreases with further increase in the N2 flow rate. The maximum Young’s modulus of the films is obtained by the doping of N and reaches 80 GPa at 10 sccm of N2 flow rate, which is measured by AFM in the scanning probe microscope mode. Meanwhile, friction characteristic of the N-doped DLC films reaches a minimum value of 0.010. 展开更多
关键词 N-DOPED DLC helicon wave plasma Young’s MODULUS FRICTION COEFFICIENT
The viscosity at the glass transition of a liquid lubricant
15
作者 Scott BAIR 《摩擦(英文版)》 CSCD 2019年第1期86-91,共6页
In the classical study of elastohydrodynamic lubrication(EHL)which does not employ real,measurable viscosity in analysis,the possibility of a glass transition has not been considered in many years.Indeed,the two rheol... In the classical study of elastohydrodynamic lubrication(EHL)which does not employ real,measurable viscosity in analysis,the possibility of a glass transition has not been considered in many years.Indeed,the two rheological assumptions of classical EHL,the Newtonian inlet and the equivalence of a traction curve to a flow curve,would not have persisted so long had the pressure dependence of the viscosity been accurately stated.With the recent appearance of viscosity obtained from viscometers in EHL analysis,the possibility of a glass transition in the contact should be reexamined,especially for the fragile traction fluids.This article employs published data for a synthetic cycloaliphatic hydrocarbon to estimate the glass transition viscosity so that,when using real viscosities in EHL simulations,the state of the liquid may be assessed.Far into the glassy state the liquid should be treated as an elastic solid with a yield stress. 展开更多
关键词 ELASTOHYDRODYNAMIC LUBRICATION glass transition high pressure VISCOSITY EHL FRICTION
氧化石墨烯对钛合金表面水润滑性能的影响 预览
16
作者 王莹 顾正鹏 +3 位作者 崔玲玲 储富强 袁宁一 丁建宁 《常州大学学报:自然科学版》 CAS 2019年第3期57-62,共6页
利用环境友好的氧化石墨烯优异的减摩抗磨性能来改善钛合金表面的摩擦学行为。制备了多层并具有晶状结构的氧化石墨烯,系统研究了氧化石墨烯对钛合金表面水润滑性能的影响。利用原子力显微镜、Raman和XRD研究了所制备氧化石墨烯的微观... 利用环境友好的氧化石墨烯优异的减摩抗磨性能来改善钛合金表面的摩擦学行为。制备了多层并具有晶状结构的氧化石墨烯,系统研究了氧化石墨烯对钛合金表面水润滑性能的影响。利用原子力显微镜、Raman和XRD研究了所制备氧化石墨烯的微观结构和成分。采用UMT-2型摩擦磨损实验机和三维光学轮廓仪研究了钛合金在不同润滑条件下的摩擦学性能。研究结果表明:与纯水溶液和含石墨粉的水溶液相比较,钛合金在以氧化石墨烯作为添加剂的水润滑条件下的摩擦系数最低,磨痕也最浅。这可能是因为氧化石墨烯在水溶液中具有良好的分散性,而且氧化石墨烯独特的层状结构使其具有低的剪切力,从而有利于改善其水润滑性能。 展开更多
关键词 钛合金 氧化石墨烯 水润滑 摩擦 磨损
在线阅读 免费下载
Research on Rebalance of Economic Globalization and Sino-US Trade Friction 预览
17
作者 Wang Na 《电子商务学刊:中英文版》 2019年第1期9-12,共4页
With the development of science and technology, informationization and economic globalization are developing faster and faster, and their impact on the world's economy and trade is also growing. The United States ... With the development of science and technology, informationization and economic globalization are developing faster and faster, and their impact on the world's economy and trade is also growing. The United States started the rebalancing strategy with tax reform as the starting point, and had large-scale trade frictions with China. How to avoid economic and trade frictions and promote sustainable economic development has become an important issue facing all countries. Although the economic and trade relations between the two countries are generally in a stable state, the friction in the trade field between the two countries exists in every stage of their economic and trade cooperation from beginning to end. The occurrence of trade friction not only affects the development of bilateral trade and regional economic development, but also may lead to a worldwide economic crisis. This paper analyzes the new forms of trade friction faced by the two countries under economic globalization through the friction between China and the United States in trade. With a view to promoting the sound development of trade between the two countries. 展开更多
关键词 Economic GLOBALIZATION Sino-US TRADE TRADE FRICTION
在线阅读 下载PDF
Effects of welding speed on the multiscale residual stresses in frictionstir welded metal matrix composites
18
作者 X.X.Zhang L.H.Wu +6 位作者 H.ANDra W.M.Gan M.Hofmann D.Wang D.R.Ni B.L.Xiao Z.Y.Ma 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第5期824-832,共9页
The effects of welding speed on the macroscopic and microscopic residual stresses(RSes) in friction stir welded 17 vol.% SiCp/2009 Al-T4 composite plates were studied via neutron diffraction and an improved decoupled ... The effects of welding speed on the macroscopic and microscopic residual stresses(RSes) in friction stir welded 17 vol.% SiCp/2009 Al-T4 composite plates were studied via neutron diffraction and an improved decoupled hierarchical multiscale modeling methods. Measurements showed that the macroscopic and total RSes had the largest variations in the longitudinal direction(LD). Increasing the welding speed led to higher values of measured LD macroscopic and total RSes in the matrix. The welding speed also significantly influenced the distributions and magnitudes of the microscopic RSes. The RSes were predicted via an improved hierarchical multiscale model, which includes a constant coefficient of friction based thermal model. The RSes in the composite plates before friction stir welding(FSW) were computed and then set as the initial states of the FSW process during modeling. This improved decoupled multiscale model provided improved predictions of the temperature and RSes compared with our previous model. 展开更多
关键词 Metal-matrix composites (MMCs) Friction STIR welding Residual/internal stress Neutron DIFFRACTION Finite element analysis (FEA) Multiscale simulation
Experimental investigations on wear properties of Palm kernel reinforced composites for brake pad applications 预览
19
作者 Satish Pujari S. Srikiran 《Defence Technology(防务技术)》 CAS CSCD 2019年第3期295-299,共5页
The use of asbestos material is being avoided to manufacture the brake pads as it is harmful and toxic in nature. Further it leads to various health issues like asbestosis, mesothelioma and lung cancers. These brake p... The use of asbestos material is being avoided to manufacture the brake pads as it is harmful and toxic in nature. Further it leads to various health issues like asbestosis, mesothelioma and lung cancers. These brake pads can be replaced by natural fibers like Palm kernel (0-50%), Nile roses (0-15%) and Wheat (0-10%) with additives like aluminum oxide (5%-20%) and graphite powder (10%-35%). Phenolic resin of 35% is utilized as a binder. Particulated Nile roses are used to increase the friction coefficient and wheat powder is used to reduce the wear rate. Aluminum oxide and graphite are abrasive in nature. This helps to make brake pads with high friction co-efficient and less wear rate with low noise pollution. The wear of the proposed composites have been investigated at different speeds. Various tests like wear on pin-ondisc apparatus, hardness on the Rockwell hardness apparatus and oil absorption test have been conducted. Phenolic resin produces good bonding nature to fiber. Thus, Fibers found to have performed palatably among all commercial brake pads. The objective of the research indicates that Palm kernal shell could be a conceivable alternative for asbestos in friction coating materials. 展开更多
关键词 Friction materials PALM KERNEL fiber NILE rose Wheat BRAKE pad WEAR TEST Hardness TEST Oil absorption TEST
在线阅读 免费下载
基于模拟实验装置进行的小型二冲程发动机缸内slap现象研究 预览
20
作者 钟赛君 王强胜 +2 位作者 卫飞 张擎鸣 肖阳 《小型内燃机与车辆技术》 2019年第3期25-29,共5页
模拟发动机点火运转状态,使用日立公司提供的发动机组建曲轴连杆机构,使用电机带动发动机运转,构建模拟试验装置进行试验研究。通过试验验证模拟试验装置的可行性,并研究活塞在气缸内的运动规律。
关键词 小型二冲程发动机 摩擦 slap现象 模拟试验 间隙
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部 意见反馈