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本文基于灵敏度分析的发动机悬置系统稳健优化设计为研究课题,以发动机悬置系统能量解耦作为本研究的参照目标,以悬置刚度参数为设计变量,考虑各种因素对悬置刚度参数灵敏度的影响,建立了多目标优化数学模型。采用遗传优化算法对发动机悬置系统刚度参数进行了稳健优化设计,并用蒙特卡罗方法进行了分析。研究结果表明,本次研究所采用的方法和建立的模型能够有效的降低发动机悬置系统能量解耦度对悬置刚度参数的灵敏度,有效的优化设计了发动机悬置系统,提高了实用性。 相似文献
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本文针对某四缸发动机模态解耦率较差的问题,对发动机悬置系统模态进行优化设计。首先通过多体动力学软件,建立6自由度发动机悬置系统模型,对模型进行模态分析和计算。以悬置元件的刚度和位置参数为主要设计变量,悬置系统模态能量解耦率为优化目标,采用遗传算法对模型进行优化。优化后,发动机悬置系统的解耦水平有显著提高。 相似文献
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基于磁流变技术的发动机隔振控制 总被引:6,自引:1,他引:6
悬置阻尼和刚度可调对发动机在宽频范围内实现积极隔振具有重要意义.在建立发动机3自由度隔振模型基础上,提出用可调阻尼的磁流变阻尼器和可调刚度的磁流变弹性体构成磁流变并联悬置系统,以降低发动机对基座的垂向传递力和抑制横向动反力矩为目标,设计出用仿人智能思想在线修改参数的垂直隔振模糊自适应控制器,并对各磁流变并联悬置的刚度和阻尼进行协调控制.用Matlab对发动机整机隔振进行仿真,搭建出发动机隔振台架试验系统,在宽频激励条件下对不同悬置的隔振效果进行对比研究.仿真表明基于磁流变并联悬置的发动机隔振控制具有明显的优势,台架试验结果表明相对于橡胶和液压悬置,磁流变液悬置能在较宽频范围把力和力矩的绝对传递率降低到约30%以内,可提高乘坐舒适性. 相似文献
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理想的发动机悬架系统应隔离发动机工作转速范围内由发动机干扰力所引起的发动机振动,并阻止由冲击而激起的发动机弹跳,这意味着发动机悬架的动态刚度和阻尼是与频率和振幅有关的,改善依赖于频率和振幅特性的动态刚度与阻尼是发动机悬架系统发展的关键所在。传统的弹性悬架不能满足所有的要求,它仅能在静偏转和隔振之间进行折衷,特别在低频域,被动的液压悬架能比弹性悬架提供更好的特性,通常半主动技术,由于其可调性而被用来进一步改善液压悬架的特性,为了隔振、低频时主动发动机悬架系统非常硬,而在高频域内被调整的非常软,主动的发动机悬架已被认为是发动机悬架的新一代,发动机悬架系统的优化是相当可取的,但发动机悬架的优化工作出现一些局限性,文中综述国内,外发动机悬架技术的现状与进展。 相似文献
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《Mechanical Systems and Signal Processing》2007,21(1):389-404
A fully rigid–elastic-coupled dynamic model was developed for a vibration isolation system consisting of a rigid vibrating machinery, multiple resilient mounts and a floating elastic panel. This model was applied to investigate the vibration power transmission behavior of an X–Y motion stage-based system used in semiconductor wire-bonding equipment. The natural frequencies and modal characteristics of the system and its subsystems were numerically evaluated. The total power flow from the X–Y motion stage (the vibrating machinery) to the equipment table (the floating elastic panel) through multiple resilient mounts and the contribution of each force component at mounting junctions to the total power flow were analysed in the concerned frequency range for different types of excitations. The total power flow predicted by the developed model was also compared with that calculated using a conventional elastic support model. It was shown that the developed model provides a more accurate prediction of the total power flow in the frequency range of interest. 相似文献
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T. Ramachandran K. P. Padmanaban 《The International Journal of Advanced Manufacturing Technology》2013,67(1-4):887-898
Though many computationally expensive internal combustion engine vibration models are available, simple and computationally efficient tools are required for preliminary design work. The unbalanced forces of rotating and reciprocating parts are the primary sources for the engine vibrations which in turn reduce the durability and reliability of consumer and commercial automotives. So, a significant vibration isolation is needed for both engine and interface between the engine mounts, and it could be obtained with the help of rotating balancing disks attached at both ends of the crank shaft. The masses of the balancing disks and their lead angles influence the effectiveness of vibration isolation that can be measured by the engine mount displacement caused due to engine vibrations. The optimized masses of balancing disks and their lead angles minimize the engine mount displacements that ensure the effective vibration isolation. In this paper, the genetic algorithm is employed to optimize the masses of the balancing disks and their lead angles with an objective of minimizing the engine mount displacements. 相似文献
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Achieving very restricted noise, vibration and harshness targets in modern vehicles, makes using the hydraulic engine mount crucial. Hydraulic engine mounts have both solid and fluid media in their structures that make their dynamic behavior complex to figure out. We present a three-dimensional model of HEM with using finite element method that encompasses elastomeric material’s nonlinearity and fluid-structure-interaction. Dynamic equivalent modulus of elasticity for elastomeric material is identified through iterative model updating procedure. To do model updating, the results (here, namely, natural frequencies and frequency response function graphs) are compared with real hydraulic engine mount behavior that derived from modal tests. The results showed that the dynamic characteristic of elastomeric material is frequency dependent and can be divided into two distinct regions: below 30 Hz (low frequency) and above 30 Hz (high frequency) with different trends. 相似文献
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Huo Rui College of Mechanical Engineering Shandong University Jinan China Shi Yin College of Power Engineering Naval University of Engineering Wuhan China 《机械工程学报(英文版)》2005,18(2):246-250
In view of difficulties concerned with direct measurement of excitations inside source equipments and their significant influence on vibration isolation effectiveness, a dynamical model, for vibration isolation of a rigid machine with six-degree-of-freedom mounted on a flexible foundation through multiple mounts, is analyzed, in which the complicated and multiple disturbances inside the machine are described as an equivalent excitation spectrum. And a method for the estimation of the equivalent excitation spectrum according to system dynamic responses is discussed for the quantitative prediction of isolation effectiveness. Both theoretical analysis and experimental results are demonstrated. Further work shows the quantitative prediction of transmitted power flow in a flexible vibration isolation experiment system using the proposed equivalent excitation spectrum method, by comparison with its testing results. 相似文献
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以横置的动力总成悬置系统为研究对象,系统地阐述了悬置系统的布置设计思想,解释了悬置系统中主惯性轴、扭矩轴以及弹性轴的定义,并对目前横置动力总成悬置系统的主要布置形式进行了研究与分析。在怠速扭矩激励下,悬置的安装位置应满足系统的扭矩轴和弹性轴重合,从而获得良好的隔振性能。同时对悬置系统的解耦作了相关的说明。横置动力总成悬置系统的布置设计分析,为悬置系统前期开发中悬置的安装位置和刚度的选择提供了参考价值。 相似文献
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Kalman Peleg 《International Journal of Mechanical Sciences》1981,23(10):595-606
Elastometer vibration and shock absorbing machinery mountings and package cushioning cannot be accurately modeled as linear Voigt type systems, since most of them exhibit stiffening or softening elasticity in conjunction with friction and viscous damping. Improved accuracy may be achieved by a non-linear shock or vibration loaded model, incorporating linear with non-linear elasticity and combined Coulomb and viscous damping. Formulae of such a model are compiled whereby optimal cushioning systems and mounts in shock and vibration loading may be designed. The use of these formulae requires experimental evaluation of two pairs of restoring and dissipative parameters in shock and vibration loading. Equations and test procedures for evaluating these parameters by means of shock and vibration machine tests are presented, along with a detailed discussion of properties of hysteresis loops of non-linear single degree of freedom systems in shock and vibration loading. A special test jig is described comprising a non-linear system with adjustable non-linear elasticity as well as variable Coulomb and viscous damping. This jig was used to evaluate the validity of the mathematical model by means of extensive tests on a shock and vibration machine. Programs developed for an Apple II microcomputer facilitated rapid and accurate computations whereby a numerical example is presented as an illustration of the procedure for evaluating restoring and dissipative parameters. This mathematical model and test procedures are believed to closely approximate shock and vibration isolation systems. As such, they may be conducive to developing better cushioning material and improved machinery mounts. 相似文献
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对装有n级橡胶阻尼式扭转减振器的发动机曲轴系统,建立其扭振分析的通程化模型。该模型适用于任意气缸数的发动机(V型或直列)曲轴系统。以优化参数的单级、两级并联和两级串联扭转减振器为例,对装有优化参数的减振器的发动机曲轴扭振进行计算比对,分析各减振器对发动机曲轴扭振的影响。计算结果表明,以控制曲轴在单简谐激励下各共振峰最小为优化目标选定的减振器,需要经过在实际发动机激励下进行强迫扭转振动分析验证后,方能实现最优选择。 相似文献
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A. A. Nuraini A. K. A. Mohd Ihsan M. J. M. Nor N. Jamaluddin 《Journal of Mechanical Science and Technology》2012,26(8):2405-2411
This paper presents the results of vibro-acoustic modeling and simulation using the finite element and the boundary element methods for the free piston engine structure. A model of the engine was constructed through the use of finite element software to perform a normal mode analysis of the engine structure. The objective was to determine the mode shapes and the natural frequency that contribute to engine structure vibration. Theoretical development of the engine balance motion and frequency response was also conducted. From the simulation and finite element analysis, the force response pattern of the engine vibration was determined and then compared with its natural frequency. The vibration data were used as the input data for noise analysis using the boundary element method. The integration of the finite element and the boundary element determined the noise-frequency data of the engine structure toward the occurrence of engine noise. The information can be used by designers to analyze engine specifications and structure, especially at the preliminary design stage. 相似文献