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Exploring the Efficiency of Experimental Construction of Sorting Ginned Cotton Seed Machine 认领
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作者 Avazbek Оbidov Muhiddin Vokhidov Jahongir Abdurahmonov 《工程(英文)(1947-3931)》 2021年第1期18-29,共12页
In this paper, research has been conducted to increase the quantity of fiber produced in the enterprise by creating a sorting device for spun seeds, dividing them into fractions by geometric dimensions, and by re-ginn... In this paper, research has been conducted to increase the quantity of fiber produced in the enterprise by creating a sorting device for spun seeds, dividing them into fractions by geometric dimensions, and by re-ginning, separating those with long fibers. A new model was developed for geometric sorting of cotton seeds in the harvest, and experiments determined its effectiveness and the optimal values of the factors affecting the efficiency using mathematical modeling. Based on the results of the study, graphs of the influence of factors on device performance and on device efficiency were constructed. 展开更多
关键词 Cotton Seeds Cotton Fiber FRACTIONS Sorting Machine Short Fiber Air Flow Vibration Machine Vibration Frequency
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Active Vibration Control of Rotating Machines with Active Machine Foot Mounts on Soft Foundations Based on a 3D-Model 认领
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作者 Ulrich Werner 《应用数学与应用物理(英文)》 2021年第1期57-87,共31页
The paper presents a simplified 3D-model for active vibration control of rotating machines with active machine foot mounts on soft foundations, considering static and moment unbalance. After the model is mathematical ... The paper presents a simplified 3D-model for active vibration control of rotating machines with active machine foot mounts on soft foundations, considering static and moment unbalance. After the model is mathematical described in the time domain, it is transferred into the Fourier domain, where the frequencies response functions regarding bearing housing vibrations, foundation vibrations and actuator forces are derived. Afterwards, the mathematical coherences are described in the Laplace domain and a worst case procedure is presented to analyze the vibration stability. For special controller structures in combination with certain feedback strategies, a calculation method is shown, where the controller parameters can be directly implemented into the stiffness matrix, damping matrix and mass matrix. Additionally a numerical example is presented, where the vibration stability and the frequency response functions are analyzed. 展开更多
关键词 Active Vibration Control Rotating Machines Actuators Steel Frame Foundation
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Systematical Development of NVH Engineering for Vehicle Electrical Powertrain Based on an Optimized V-Model 认领
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作者 Shaoyou Shi Kaiyu Yu Zecheng Zhong 《力学国际期刊(英文)》 2021年第2期7-15,共9页
For systematical NVH development of vehicle (especially for mass-production passenger vehicles) electric powertrain, an optimized V-Model is designed and has been implemented in the entire component-vehicle developmen... For systematical NVH development of vehicle (especially for mass-production passenger vehicles) electric powertrain, an optimized V-Model is designed and has been implemented in the entire component-vehicle development, which integrates three individual branches: simulation, validation and optimization. Compared to the V-models in the traditional sense, this optimized V-model is not only driven by requirement and task accomplishment but also maximum optimization of NVH system performance. In this case, developing procedures are capable to be efficiently iterated and the NVH engineering can be expanded into 3D with this V-model. 展开更多
关键词 V-Model NVH (Nosie Vibration and Harshness) SEP (System Engineering Process) Electrical Powertrain MBS (Multi-Body System) Acoustic Electromagnetic Gear Mesh Topology Optimization
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城市轨道车辆车体被动式吸振器减振设计研究 认领
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作者 宗志祥 《铁道机车车辆》 北大核心 2021年第1期123-128,共6页
针对城市轨道车辆车体振动的问题,建立了含被动式吸振器的车轨垂向振动模型,指出了传统二自由度被动式吸振器应用在轨道车辆上的局限性,提出了适用于城市轨道车辆车体被动式吸振器减振设计方法,利用Sperling平稳性指标验证了被动式吸振... 针对城市轨道车辆车体振动的问题,建立了含被动式吸振器的车轨垂向振动模型,指出了传统二自由度被动式吸振器应用在轨道车辆上的局限性,提出了适用于城市轨道车辆车体被动式吸振器减振设计方法,利用Sperling平稳性指标验证了被动式吸振器在不同速度和载客量工况下的减振效果,探讨了被动式吸振器的安装可行性。研究结果表明:传统被动式吸振器的减振最佳点偏离了车体固有频率点,存在一定的偏差;优化设计后的被动式吸振器的最佳减振点和车体固有频率点相互吻合,具有最优减振效果。不同速度和载客量工况下,优化设计的被动式吸振器都能获得较好的减振效果,应用在轨道车辆车体上具有可行性。为利用被动式吸振器来降低车体振动的研究和应用提供了参考依据。 展开更多
关键词 振动 被动式吸振器 车体 目标频率 最佳减振点
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Dynamic response analysis of train-induced vibration impact on the Probhutaratna pagoda in Beijing 认领
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作者 Li Minghang Ma Meng +2 位作者 Cao Zhonglei Xia Qian Liu Weining 《地震工程与工程振动:英文版》 SCIE EI 2021年第1期223-243,共21页
Train-induced vibration exhibits a potential dynamic impact on historic buildings and especially on those with high historical and cultural value.Under the long-term reciprocating load of train vibrations,structural f... Train-induced vibration exhibits a potential dynamic impact on historic buildings and especially on those with high historical and cultural value.Under the long-term reciprocating load of train vibrations,structural fatigue damage can occur,and thus,a significant problem involves effectively evaluating and mitigating vibration impact on historic buildings while developing a rail transit system.In the present study,train-induced vibration impact and dynamic behavior of Probhutaratna pagoda in the suburb of Beijing,which has a history of approximately 1000 years,was investigated.To examine the dynamic behavior of the Probhutaratna pagoda and determine the weakest position in its architectural damage under train loads,its dynamic characteristics were measured.The free vibration modes were identified based on the dynamic measurement results.Subsequently,a finite element(FE)model of the Probhutaratna pagoda was constructed and the models and train-induced structural responses were compared with measured results.Finally,the structural dynamic responses to moving train loads were analyzed in detail.The results indicate the following conclusions.(1)The dominant frequency of the ambient vibration is below 4 Hz,and the dominant frequency of the train-induced vibration is between 8 and 16 Hz.(2)The first,second,and third order natural frequencies are 1,3.25,and 6 Hz,respectively,in the west-east direction,and are 1,3.25,and 6.25 Hz,respectively,in the north-south direction.(3)The two weakest locations(A and B)of the Probhutaratna pagoda are observed at the spire bottom and west gate of the first floor.At location A,the maximum principal stress reached 243.6 N/m^2 and the corresponding maximum tensile strain reached 3.74×10^-7. 展开更多
关键词 historic building vibration measurement numerical simulation train-induced vibration modal identification
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高速旋转状态下高压涡轮叶盘振动试验研究 认领
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作者 罗莉 黄大永 《航空工程进展》 2021年第1期85-90,共6页
在高速旋转状态下,开展对高压涡轮转子叶片的振动特性和缘板阻尼装置减振效果的试验研究,有利于后期的设计迭代,获得真实的叶片振动情况。以高压涡轮转子模拟件为对象,采用雾化油滴非接触式激励方式模拟涡轮叶片周期性气动激励,建立高... 在高速旋转状态下,开展对高压涡轮转子叶片的振动特性和缘板阻尼装置减振效果的试验研究,有利于后期的设计迭代,获得真实的叶片振动情况。以高压涡轮转子模拟件为对象,采用雾化油滴非接触式激励方式模拟涡轮叶片周期性气动激励,建立高速旋转状态下高压涡轮转子叶片振动特性试验系统,并进行介于静止状态夹具固定式测试和整机直接测试之间的组件级试验,在高速旋转状态下实现叶片非接触式高频激振,获取叶片的振动特性和缘板阻尼装置对转子叶片的减振效果。结果表明:在常温10000~19000 r/min运行转速下,缘板阻尼装置对转子叶片减振约40%,阻尼质量较大的叶片频率较高。 展开更多
关键词 高压 涡轮 转子叶片 振动 阻尼 减振
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Experimental study on integral axial squeeze film damper to suppress longitudinal vibration of propulsion shafting 认领
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作者 范文强 He Lidong +3 位作者 Jia Xingyun Yan Wei Zhu Gang Wang Jian 《高技术通讯:英文版》 EI CAS 2021年第1期76-85,共10页
This paper aims at investigating the effectiveness of squeeze oil film in suppressing the longitudinal vibration of propulsion shaft systems through a novel integral axial squeeze film damper(IASFD).After designing th... This paper aims at investigating the effectiveness of squeeze oil film in suppressing the longitudinal vibration of propulsion shaft systems through a novel integral axial squeeze film damper(IASFD).After designing the IASFD,a propulsion shafting test rig for the longitudinal vibration control is built.Longitudinal vibration control experiments of the propulsion shafting are carried out under different magnitude and frequency of the excitation force.The results show that both IASFD elastic support and IASFD elastic damping support have excellent vibration attenuation characteristics,and can effectively suppress the longitudinal vibration of the shaft system in a wide frequency range.However,IASFD elastic damping support has a more significant vibration reduction effect than the other supports,and increasing the damping of the system has obvious effect on reducing the shafting vibration.For an excitation force of 45 N,the maximum reduction of the vibration amplitude is 89.16%.Also,the vibration generated by the resonance phenomenon is also significantly reduced. 展开更多
关键词 integral axial squeeze film damper(IASFD) propulsion shafting longitudinal vibration vibration damping
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The Study of Tubing Vibration Mechanism in High Pressure Gas Well 认领
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作者 Jingbing Luo Kui Zhang +2 位作者 Junlin Liu Lingyu Mu Fujun Wang 《世界工程和技术(英文)》 2021年第1期128-137,共10页
Deep gas wells and gas fields have the characteristics of high pressure. The vibration of the tubing string during the production of gas wells causes the string to be subjected to severe stress and even dynamic fatigu... Deep gas wells and gas fields have the characteristics of high pressure. The vibration of the tubing string during the production of gas wells causes the string to be subjected to severe stress and even dynamic fatigue failure. Therefore, this article is based on the dynamic finite element theory, aiming at the characteristics of large-size tubing strings in deep gas wells. The finite element mechanics model and mathematical model of the tubing string vibration of the packer of high-pressure gas wells were established, and the ANSYS software was re-developed. The finite element analysis program for the vibration dynamics of the unbuckled and buckled strings of gas wells was compiled with APDL, and the displacement of the longitudinal vibration of the tubing string of high-pressure gas wells was studied. According to different sizes of tubing strings currently used in deep gas wells and gas fields, simulation calculations are carried out, and the axial impact load and buckling damage laws of the tubing strings of the entire well section under different production rates are obtained. It provides a theoretical basis for the prediction of tubing string vibration law and measures to prevent tubing string vibration. 展开更多
关键词 Deep Gas Well High Pressure Gas Well Tubing VIBRATION DAMAGE BUCKLING Finite Element
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文章速递Spring-Value in Kirchhoff-Love Plate: Displacement, Buckling, Pure-Shear, Vibration 认领
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作者 Tonye Ngoji Johnarry 《土木工程期刊(英文)》 2021年第1期96-118,共23页
The stiffness model of the finite element is applied to the Kirchhoff-love closed-form plate buckling;buckling is always in focus in plate assemblages. The useful Eigen-value solutions are unable to separate a square ... The stiffness model of the finite element is applied to the Kirchhoff-love closed-form plate buckling;buckling is always in focus in plate assemblages. The useful Eigen-value solutions are unable to separate a square plate from a much weaker long one in the most commonly-used all-simply supported plate (SSSS), among others. Spring-values of the Kirchhoff-Love plate are sought;once found, displacement-factors can be determined. Comparative </span><span style="font-family:Verdana;">displacements allow </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">an </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">easier and better evaluation of buckling-factors,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> pure-shear, vibration and so are termed “buckling-displacement-factors”. In testing, many plates in mixed boundary conditions are evaluated for displacement</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">assisted buckling-solutions, first. The displacement-factors made from fundamental Eigen-vectors, in a single-pass, are found to be within about one-percent of known elastic values. It is found that the Kirchhoff-Love plate</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">spring and the finite-element spring, demonstrated, here, in the assemblage of beam-elements, are equivalent from the results. In either case</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> stiffness is first assembled, ready for any loading—transverse, buckling, shear, vibration. The simply-supported plate draws the only exact vibration solution, and so, in an additional new effort, all other results are calibrated from it;direct vibration solutions are made for comparison but such results are, hardly, better. In the process, interactive Kirchhoff-Love plate-field-sheets are presented, for design. It is now additionally demanded that the solution Eigen-vector be </span><span style="font-family:Verdana;">developable into a recognizable deflection-factor. A weaker plate cannot possess greater buckling strength, this is a check;to find stiffness the</span><span style="font-family:Verdana;"> deflection-factor must be exact or nearly so. Several examples justify the characteristic buckling displacement-factor as a new tool</span></span></span></span><span style="font-family:Verdana;">. 展开更多
关键词 Spring-Stiffness Rectangular Plates Deflections Buckling Pure-Shear Vibration Plate’s-Field-Sheet
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文章速递Influence of Metabolic Syndrome on Vibration Perception Threshold in First-Degree Relatives of Type 2 Diabetes Mellitus 认领
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作者 Lili Yang Peng Yun +3 位作者 Dan Liu Zhen Zhang Xuemei Yu Fangping Li 《长江医药(英文)》 2021年第1期43-53,共11页
<strong>Objectives: </strong>To investigate influence of metabolic syndrome on vibration perception threshold in first-degree relatives of type 2 diabetes who were not diagnosed with diabets before. <st... <strong>Objectives: </strong>To investigate influence of metabolic syndrome on vibration perception threshold in first-degree relatives of type 2 diabetes who were not diagnosed with diabets before. <strong>Material and Methods:</strong> First-degree relatives of type 2 diabetes at the age of 40 - 60 s who had not been diagnosed with diabetes before were enrolled. Height, weight, waist circumference, hip circumference, blood pressure (systolic and diastolic blood pressure), body fat percentage, fasting plasma lipid, fasting plasma glucose, 2-hour blood glucose after 75 g oral glucose and vibration perception threshold were measured. <strong>Results:</strong> 58 subjects were diagnosed with the level of vibration perception threshold ≥ 16 V. Vibration perception threshold in the metabolic syndrome group was significantly higher than that in the non-metabolic syndrome group (<em>P</em> < 0.05). Vibration perception threshold increased with the increase of metabolic syndrome component. The group with ≥3 components of metabolic syndrome had a significantly higher level of vibration perception, as compared with that of group with 0 component, group with 1 component of metabolic syndrome (<em>p</em> < 0.01). Group with 2 components of metabolic syndrome had a significantly higher level of vibration perception threshold when comparing with group with 0 component (<em>P</em> < 0.05). Vibration perception threshold was positively correlated with weight, body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, fasting plasma glucose and 2-hour blood glucose. Stepwise multiple regression analysis showed that there was a positive correlation between waist circumference, systolic blood pressure and vibration perception threshold. <strong>Conclusion:</strong> Some first-degree relatives of type 2 diabetes who have not been diagnosed with diabetes have high risk of peripheral neuropathy, especially those with metabolic syndrome. Waist circumference and blood pressure are the main factors affecting Vibration perception threshold levels. Early detection of vibration perception threshold should be performed in first-degree relatives of type 2 diabetes with metabolic syndrome. Waist circumference and blood pressure may be important risk factors of peripheral neuropathy for them. 展开更多
关键词 Metabolic Syndrome Vibration Perception Threshold Diabetes Mellitus
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1030 MW超超临界机组引风机芯轴断裂原因分析 认领
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作者 闫飞 沈利 +2 位作者 谢增孝 董旭光 陈溪松 《电站系统工程》 2021年第2期53-55,57,共4页
某电厂2×1030 MW超超临界机组引风机多次出现芯轴断裂故障,给发电机组安全运行埋下隐患。为消除该隐患,通过阐述引风机芯轴断裂前运行参数变化,并从引风机芯轴断口、受力、设计等方面分析出引起引风机芯轴断裂原因。结果表明:引风... 某电厂2×1030 MW超超临界机组引风机多次出现芯轴断裂故障,给发电机组安全运行埋下隐患。为消除该隐患,通过阐述引风机芯轴断裂前运行参数变化,并从引风机芯轴断口、受力、设计等方面分析出引起引风机芯轴断裂原因。结果表明:引风机芯轴断裂前运行参数已经出现一定变化,通过优化芯轴设计、运行操作、检修等方式可以避免发生芯轴断裂事故,提高机组运行稳定性。 展开更多
关键词 引风机 振动 芯轴断裂 叶片积灰 滑动轴承磨损
高线速度水润滑轴承振动研究 认领
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作者 王培培 《中国重型装备》 2021年第1期37-39,共3页
对不同轴承间隙、不同轴瓦材料下的水润滑轴承开展了摩擦特性及振动特性研究。正交试验结果表明当轴承间隙约0.2 mm(间隙比约2.5‰)时,水润滑轴承摩擦系数最小。振动特性试验表明:不同材料轴瓦振动特性不同。
关键词 水润滑轴承 振动 高线速度
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基于振动监测的船用燃油泵故障诊断 认领
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作者 王溢镛 王艳武 高洪滨 《机电工程技术》 2021年第1期163-165,共3页
针对某船用燃油泵在航行途中振动偏大的问题,在对其基本结构、工作原理以及运行特征分析的基础上,利用轴承脉冲检测仪结合频谱测量仪,对其运行状态进行分析,数据显示轴承脉冲在正常范围内,电机输出端和自由端水平方向振动超标,振动以转... 针对某船用燃油泵在航行途中振动偏大的问题,在对其基本结构、工作原理以及运行特征分析的基础上,利用轴承脉冲检测仪结合频谱测量仪,对其运行状态进行分析,数据显示轴承脉冲在正常范围内,电机输出端和自由端水平方向振动超标,振动以转频为主;转轴联轴器两端水平方向相位差接近180°。分析诊断为该泵存在不对中故障,检修后该泵恢复正常,保证了船舶的正常航行。 展开更多
关键词 燃油泵 振动 故障诊断
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Microstructure and mechanical properties of AZ91D magnesium alloy by expendable pattern shell casting with different mechanical vibration amplitudes and pouring temperatures 认领
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作者 Suo Fan He-bao Wu Jin-xiu Fang 《中国铸造:英文版》 SCIE CAS 2021年第1期1-8,共8页
To refine the microstructure and improve the mechanical properties of AZ91 D alloy by expendable pattern shell casting(EPSC),the mechanical vibration method was applied in the solidification process of the alloy.The e... To refine the microstructure and improve the mechanical properties of AZ91 D alloy by expendable pattern shell casting(EPSC),the mechanical vibration method was applied in the solidification process of the alloy.The effects of amplitude and pouring temperature on microstructure and mechanical properties of AZ91 D magnesium alloy were studied.The results indicated that the mechanical vibration remarkably improved the sizes,morphologies and distributions of the primaryα-Mg phase andβ-Mg17 Al12 phase,and the densification and tensile properties of the AZ91 D alloy.With an increase in amplitude,the microstructures were gradually refined,resulting in a continuous increase in mechanical properties of the AZ91 D alloy.While,with the increase of pouring temperature,the microstructures were continuously coarsened,leading to an obvious decrease of the mechanical properties.The tensile strength and yield strength of the AZ91 D alloy with a vibration amplitude of 1.0 mm and a pouring temperature of 730℃were 60%and 38%higher than those of the alloy without vibration,respectively. 展开更多
关键词 AZ91D magnesium alloy expendable pattern shell casting mechanical vibration MICROSTRUCTURE mechanical properties
圆锥滚子轴承滚道参数与振动的灰关联及优化分析 认领
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作者 庞晓旭 何青竹 +2 位作者 杨丹峰 李梦凯 陈立海 《轴承》 北大核心 2021年第1期66-71,共6页
针对圆锥滚子轴承滚道参数对轴承振动的影响,以32210圆锥滚子轴承为研究对象,利用灰关联方法分析了轴承内外圈滚道的圆度、波纹度和表面粗糙度对轴承振动的影响程度,并采用定性融合方法对影响程度进行了融合分析,以此为基础采用响应曲... 针对圆锥滚子轴承滚道参数对轴承振动的影响,以32210圆锥滚子轴承为研究对象,利用灰关联方法分析了轴承内外圈滚道的圆度、波纹度和表面粗糙度对轴承振动的影响程度,并采用定性融合方法对影响程度进行了融合分析,以此为基础采用响应曲面法建立回归分析模型获得滚道参数的最佳组合,优化结果表明,轴承振动的最小期望值可以减小到37 dB。 展开更多
关键词 滚动轴承 圆锥滚子轴承 滚道 振动 灰关联 响应曲面 参数优化
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振动和搅拌对SiO2纳米颗粒聚团流化的影响对比研究 认领
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作者 赵之端 赵蒙 +3 位作者 刘道银 梁财 马吉亮 陈晓平 《工程热物理学报》 EI CAS 北大核心 2021年第1期136-142,共7页
纳米颗粒聚团间的黏性力较强,通常需要一定的辅助方法才能实现稳定流化。本文对比了振动、搅拌、以及振动和搅拌组合方法对SiO2纳米颗粒聚团流化特性的影响。结果表明,振动能消除沟流和节涌,提高床层膨胀高度,但当振动强度超过15.7 m... 纳米颗粒聚团间的黏性力较强,通常需要一定的辅助方法才能实现稳定流化。本文对比了振动、搅拌、以及振动和搅拌组合方法对SiO2纳米颗粒聚团流化特性的影响。结果表明,振动能消除沟流和节涌,提高床层膨胀高度,但当振动强度超过15.7 m·s-2后,振动会对流化产生负面影响。搅拌能显著提高床层膨胀比,但当转速超过200r/min后,流化床的稳定性逐渐降低。振动和搅拌的复合作用能在单场辅助流化的基础上进一步提高纳米颗粒聚团的流化质量,提高床层膨胀比,降低临界流化速度,将聚团尺寸减小到50〜150μm之间.振动和搅拌分别在垂直和水平方向上作用于床层,对纳米颗粒聚团流化的改善存在协同作用,但搅拌对流化的影响比振动的影响更为明显。 展开更多
关键词 纳米颗粒聚团 流化 振动 搅拌
基于ProE建模及受力分析的振动送料设备包装设计 认领
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作者 马永胜 《自动化与仪器仪表》 2021年第1期197-200,共4页
为了提高振动送料设备包装的可靠性,提出基于ProE建模及受力分析的振动送料设备包装设计方法。构建振动送料设备包装构件的受力分析模型,结合误差敏感性调节方法进行振动送料设备包装过程中的受力特征信息分析,通过ProE建模方法构建振... 为了提高振动送料设备包装的可靠性,提出基于ProE建模及受力分析的振动送料设备包装设计方法。构建振动送料设备包装构件的受力分析模型,结合误差敏感性调节方法进行振动送料设备包装过程中的受力特征信息分析,通过ProE建模方法构建振动送料设备包装受力分析模型,通过受力参数融合迭代和跟踪识别方法,进行振动送料设备包装传感信息处理,在执行机构中进行振动送料设备包装的位移参数分析和受力可靠性分析,建立振动送料设备包装构件力学信息辨识和优化融合模型,通过位移补偿和力学轨迹调节方法,实现振动送料设备包装过程的优化控制设计。仿真结果表明,采用该方法进行振动送料设备包装设计的建模可靠性的较好,包装过程控制能力较强,输出误差较低。 展开更多
关键词 ProE建模 受力分析 振动 送料设备 包装 过程控制
HX系列机车交流牵引电机典型故障分析与解决方案 认领
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作者 牛志钧 卫文改 王鑫 《铁道机车车辆》 北大核心 2021年第1期95-99,共5页
随着现代大功率HX系列机车牵引电机运行里程数的增加,牵引电机在线运行后暴露故障问题也逐渐增多,文中对牵引电机检修过程中出现的典型故障进行了汇总归类分析,有助于牵引电机检修人员快速识别故障并找到解决方案。
关键词 机车 牵引电机 振动
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小流量工况下比例溢流阀振动问题研究 认领
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作者 邢敏 刘汉余 董万玉 《液压气动与密封》 2021年第2期71-73,70,共4页
针对液压系统中,小流量工况下,比例溢流阀引起的回路振动问题,简化和分析了试验回路,并通过对比试验和对比例溢流阀结构及力平衡方程的分析,研究了比例溢流阀动态特性影响因素和小流量状态下振动问题的起因。经过分析,比例溢流阀固定阻... 针对液压系统中,小流量工况下,比例溢流阀引起的回路振动问题,简化和分析了试验回路,并通过对比试验和对比例溢流阀结构及力平衡方程的分析,研究了比例溢流阀动态特性影响因素和小流量状态下振动问题的起因。经过分析,比例溢流阀固定阻尼孔的直径为影响其动态特性的主要因素之一。经过理论推导和试验验证,在溢流阀下面加过度块和阻尼的方法,能够很好地解决小流量工况下比例溢流阀引起的回路振动问题,阻尼孔的大小可以通过试凑的方式得到。 展开更多
关键词 比例溢流阀 振动 阻尼孔 研究
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Finite-Time Convergence Disturbance Rejection Control for a Flexible Timoshenko Manipulator 认领
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作者 Zhijia Zhao Zhijie Liu 《自动化学报:英文版》 SCIE EI 2021年第1期157-168,共12页
This paper focuses on a new finite-time convergence disturbance rejection control scheme design for a flexible Timoshenko manipulator subject to extraneous disturbances.To suppress the shear deformation and elastic os... This paper focuses on a new finite-time convergence disturbance rejection control scheme design for a flexible Timoshenko manipulator subject to extraneous disturbances.To suppress the shear deformation and elastic oscillation,position the manipulator in a desired angle,and ensure the finitetime convergence of disturbances,we develop three disturbance observers(DOs)and boundary controllers.Under the derived DOs-based control schemes,the controlled system is guaranteed to be uniformly bounded stable and disturbance estimation errors converge to zero in a finite time.In the end,numerical simulations are established by finite difference methods to demonstrate the effectiveness of the devised scheme by selecting appropriate parameters. 展开更多
关键词 Disturbance observer disturbance rejection control finite-time convergence Timoshenko manipulator vibration control
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