共查询到19条相似文献，搜索用时 279 毫秒
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发动机扭转振动是影响汽车NVH特性的主要因素之一。双质量飞轮具有优异的扭振减振效果,使用越来越广泛。扭转弹簧与阻尼元件作为双质量飞轮(简称DMF)的主要减振单元,决定了其减振性能。本文以周向长弧形弹簧式双质量飞轮(DMF-CS)为研究对象,对其扭振特性进行了研究,建立了DMF-CS的结构与动力学模型,并对VM发动机动力传动系统扭振特性进行了分析与研究。首先,分析双质量飞轮的组成结构特征,将怠速工况下匹配双质量飞轮的汽车动力传动系统简化成二自由度扭振系统,分析了不同转动惯量比和不同扭转刚度时的系统幅频响应特性。其次,建立匹配DMF-CS的VM发动机动力传动系统的扭振动力学模型,对怠速工况下和行驶工况下动力传动系统扭振的固有特性进行分析。最后,通过MATLAB软件计算,分析了DMF-CS对怠速扭振的影响,并得出了行驶工况的固有扭振特性。 相似文献
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针对某前置后驱车型在高挡位中低转速范围内存在的轰鸣声问题,本文首先根据以往学者的研究和实践采用集中质量法建立动力传动系扭转振动模型,通过AMESim软件仿真计算动力传动系的扭转振动模态频率,并进行了强迫振动分析,对比扭转振动试验结果验证了模型的有效性。然后分别以扭转振动峰值对应的二阶共振频率和变速器输入二阶扭振幅值随发动机转速变化的曲线为目标,对发动机、变速器、传动轴与半轴分支子结构重新进行简化合并,最终得到新的6自由度和13自由度模型。该简化方法为后续研究和治理动力传动系扭转振动问题提供了基础。 相似文献
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重视机械结构系统的动力学问题,研究机械系统在实际工作状态下的受力变化、运动情况及其动态行为,以满足机械结构静、动态特性及低振动、低噪声的要求。因此,有必要对所设计的减速器系统进行扭振动力学分析,找到影响动态特性的薄弱环节,从而为进一步动态结构优化设计、提高减速器的动态性能提供了理论依据。 相似文献
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随着经济的快速发展,汽车已经成为了居民的消费品走入了百姓生活之中,改变了人们日常出行方式。由于现代工业的发展带动了汽车相关部件的研发,促进了汽车整体的安全性和舒适性的提高。但是实际研究中发现,汽车在行驶的过程中,经常出现传动系扭振的问题,此现象的发生导致了汽车整体噪音严重超标,而且随着汽车使用时间的越长造成的扭振现象越剧烈,汽车舒适性面临着严峻的挑战,同时该问题已经成为影响汽车工业发展的重要限制因素。 相似文献
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汽轮发电机组轴系结构变化对扭振固有频率的影响 总被引：1，自引：0，他引：1
轴系本身结构的合理设计或结构参数重新调整从而避开共振，是防止和减小扭振的重要措施之一。本文以某型300MW汽轮发电机组试验台转子为例，分析了其各阶扭振频率针对局部结构的刚度和转动惯量改变时的敏感度，归纳了轴系扭振固有频率对局部结构变化的敏感性的一般规律，为有效的调频工作提供参考。 相似文献
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离合器的功能就是切断及实现对传动系的动力传递,能够起到限制传动系所承载的最大转矩的作用,避免由于传动系各零件过载而出现设备损坏的现象。本文对汽车离合器的设计要求进行分析,对离合器的软件设计进行概述,对结构形式不同的执行机构离合器设计进行研究,通过确定设计变量、目标函数以及约束条件,对离合器进行优化分析。 相似文献
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以无阻尼单自由度主系统以串联方式安装两个阻尼动力吸振器为研究对象,通过建立力学模型、建立运动微分方程、得出主系统振幅表达式与振幅放大率表达式、对吸振器参数优化设计四个步骤,确立了对组合式动力吸振器参数的计算机编程优化设计方法,得出了最优振幅放大率曲线。并在吸振器总质量与主系统质量之比相同条件下比较了组合式动力吸振器与单一式动力吸振器的吸振效果。 相似文献
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3G通信基站电源系统是3G系统重要组成部分。首先介绍了3G通信基站电源系统的原理及组成,然后针对故障原因进行分析,并提出了防雷的解决方案。实践证明,方案简单可行。 相似文献
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Yasmine El-Ashi Taha Landolsi Rached Dhaouadi 《Journal of The Franklin Institute》2011,348(7):1435-1455
In this paper, we study the accuracy of an optical vibration sensing system using Gaussian beam analysis. The proposed optical system uses a He-Ne laser source whose Gaussian beam impinges on a quad-cell photodetector array. The normalized optical power for each cell is obtained through numerical simulation based on the well-known Gaussian beam optics formulation, as the beam scans the plane of the photodetectors due to vibration. The system detection principle lies upon finding a relationship between the power distribution of the quad-cell and the position of the beam centroid, which allows us to identify the characteristics of the vibration applied, such as direction, frequency and strength. The aspects of practical implementation and experimental limitations on the power distribution accuracy are discussed and the discrepancies with the theoretical results are presented. 相似文献
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Dynamic vibration absorbers (DVA) provide a cheap and efficient means for vibration abatement in many complex systems, ranging from crankshafts of internal combustion engines, overhead transmission lines, machine casings, structural panels and large turbo machinery sets, to quote a few examples. One can provide a simple classification for them by considering the nature of the resilient material it contains as a form of “spring”: it may be viscous (CDVA), hysteretic (HDVA) or viscoelastic (VDVA). Viscous DVAs are the largely studied devices and one of their most remarkable applications is in mitigating crankshafts torsional vibrations and in very tall buildings. The most well known hysteretic DVA is the Stockbridge damper, largely applied in overhead electric power transmission lines. With modern use of fractional calculus, modelling viscoelastic materials became a routine work. The experimental identification of four fractional parameter models for viscoelastic material has become a standard technique amongst the authors of this work. Modelling viscoelastic materials by four fractional parameters has made advanced analysis of structures and systems where it is applied much more straightforward than it was before. This is true also for structures with VDVA and HDVA attached to it. In this paper it is shown that a hysteretic material model can be derived from a viscoelastic material model based on four fractional parameters. Generalized quantities of ordinary and pendulum type absorbers and for both viscoelastic and hysteretic materials are derived and their nature discussed. The performances of a system with absorbers of viscoelastic and hysteretic nature are compared. Input energy and dissipated energy by the absorbers of both natures and types are computed and compared, using the concept of generalized damping parameter of the absorbers. Conclusions are drawn from the comparisons. One of the ideas behind these computations is to check the validity of some international recommendations for the experimental assessment of Stockbridge dampers, which implicitly neglects the effect of the generalized mass parameter. 相似文献
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《Journal of The Franklin Institute》2022,359(14):7677-7707
The inerter has garnered much attention in the past two decades owing to its unique mechanical characteristics. As a substitution of the capacitance element based on the electrical-mechanical analogy, the inerter has outstanding advantages. Extensive investigations have been conducted for the development of inerter-based vibration isolation system. This paper provides a retrospective perspective and an update on the inerter's progress for vibration isolation in different fields. The advantages of inerter compared with mass element are analyzed and revealed. Some existing reviews and highly-cited papers are summarized to outline the inerter development progress. Thereafter, the inerter is reviewed in detail from the perspective of network analogy and synthesis, mechanical domain, and power flow transmission. The devices improvement and control approach are summarized. Finally, the significance of inerter research, the challenge in current studies, and promising inerter application fields are presented and discussed. This paper is closed by conclusions, which highlight the necessity of inerter research, current challenges, and future research directions. 相似文献
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针对输变电工程施工安全评估的特点,全面考虑风险指标定性概念模糊性和不确定性,研究一种定性分析与客观计算相结合的评价方法。首先以输变电工程的施工过程为研究对象,对影响输变电工程施工阶段的各风险因素进行归类分析,并结合4M1E理论建立风险指标体系,为避免传统模型权重分配的单一性,引入三角模糊数进行主客观综合赋权来确定各指标权重;然后结合云模型本身不确定性推理特性兼具定性、定量分析的特点,构建基于三角模糊数的云模型进行评估;最后通过Matlab仿真分析表明研究方法的可行性和适用性。 相似文献
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针对输变电工程数据管理在数据处理、数据质量与安全等方面缺乏完整数据管理技术标准体系的问题,通过调研现有标准,明确输变电工程数据管理技术标准存在的问题及需求。立足于该需求,确立输变电工程数据管理技术标准系统目标,建立输变电工程数据管理技术标准关联模型。通过对输变电工程数据管理技术标准依存主体常用词汇的抽取,形成输变电工程数据管理技术标准的初步类图并进行分组。同时,构建输变电工程数据管理技术标准体系结构,提出输变电工程数据管理技术标准体系框架,为完善输变电工程数据管理技术标准体系提供参考。 相似文献
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为准确掌握输电线路的振动状态,预测导线疲劳程度,本文通过Miner累计损伤理论及W魻hler安全边界曲线分析了输电线路疲劳寿命的估计方法,设计了一种基于传感器技术,数据采集技术、无线通信技术等的输电线路微风振动监测系统,该系统主要由振动监测模块、监测基站及监测中心组成,将该监测系统安装于某段输电线路,实际运行结果表明,该系统性能良好。 相似文献
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分析了电力系统通信网的主要特点,介绍了光纤通信的波分复用和光栅型波分复用器的工作原理,对电力通信中光纤通信的应用状况进行了概括,最后对电力系统中光纤通信网的发展做了展望。 相似文献