共查询到20条相似文献,搜索用时 421 毫秒
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该文采用一种由Mooney-Rivlin模型和多个Maxwell模型叠加组成的非线性粘弹性本构模型,用于计算橡胶隔振器的高频动态特性。该文给出了在时域和频域范围内拟合本构模型中粘弹性参数的方法,利用拟合得到的本构模型参数,对某款橡胶悬置跨点动态特性进行计算,并与实验结果进行对比。该文还建立了橡胶隔振器等效力学模型,分析了原点动刚度和跨点动刚度的区别,分析表明:使用跨点动态特性测试法可消除测试中附加惯性力的影响,适用于橡胶隔振器高频动特性的测试;同时,该文搭建了橡胶隔振器有限元模型,分别用于分析其跨点动刚度与原点动刚度,并将分析结果与实验结果进行对比,分析结果验证了有限元模型和力学模型的正确性。除此之外,该文还分析对比了时域(松弛、蠕变)和频域(简谐动态试验)拟合粘弹性参数方法的优缺点。 相似文献
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《振动与冲击》2016,(13)
针对目前用于非圆精密加工的快速伺服刀架只能提供单向驱动力的问题,设计了一种基于柔性铰链的新型快速伺服刀架。建立了刀具放大结构的力学模型,利用理论力学的知识推导出刀具的放大率、刚度和固有频率解析式,并对实验刀具进行有限元分析。为了验证理论计算和有限元分析结果的准确性,对刀具进行实验测试。测试结果显示,理论计算结果与实验结果的最大误差为14.87%,平均误差为12.635%,有限元分析结果与实验结果的最大误差为6.54%,平均误差为5.925%,表明理论计算和有限元分析的准确性。最后提出了一种快速伺服刀架参数的初选流程,为快速伺服刀架的研究提供一定的理论基础。 相似文献
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为有效开展整车操稳性、平顺性的仿真研究,有必要对影响较大的汽车悬架衬套的静、动刚度范围进行精确设计及控制。本文通过采用3阶Ogden超弹性本构模型与3阶PRONY级数粘弹性模型建立了某汽车悬架减振器橡胶连接衬套超-粘弹性有限元模型,利用ABAQUS/Standard有限元分析模块分别研究了衬套缩径量大小与静、动刚度的关系,得到了不同缩径量下橡胶衬套静、动刚度曲线;结果表明,当缩径量小于0.6mm时,橡胶衬套静、动刚度随缩径量的增加而增大并呈近似的线性关系;当缩径量大于0.6mm后,静、动刚度随缩径量增大而增大的速率急剧变大而呈现非线性关系;本文研究说明,当缩径值达到一定程度后对橡胶衬套静、动刚度值的影响变大;最后通过试验测试发现有限元分析结果与测试结果相对误差在10%以内,证明了本次考虑缩径量影响的汽车悬架衬套静动特性分析的正确性,这对车用橡胶衬套的设计与分析研究具有一定的指导意义。 相似文献
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《噪声与振动控制》2019,(1)
为有效开展整车操稳性、平顺性的仿真研究,有必要对影响较大的汽车悬架衬套的静、动刚度范围进行精确设计及控制。采用3阶Ogden超弹性本构模型与3阶PRONY级数黏弹性模型建立某汽车悬架减振器橡胶连接衬套超-黏弹性有限元模型,利用ABAQUS/Standard有限元分析模块分别研究衬套缩径量大小与静、动刚度的关系,得到了不同缩径量下橡胶衬套静、动刚度曲线;结果显示,当缩径量小于0.6 mm时,橡胶衬套静、动刚度随缩径量的增加而增大并呈近似的线性关系;当缩径量大于0.6 mm后,静、动刚度随缩径量增大而增大的速率急剧变大而呈现非线性关系;研究表明,当缩径值达到一定程度后对橡胶衬套静、动刚度值的影响变大;最后通过试验测试发现有限元分析结果与测试结果相对误差在10%以内,证明考虑缩径量影响的汽车悬架衬套静动特性分析的正确性,这对车用橡胶衬套的设计与分析研究具有一定的指导意义。 相似文献
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在不同振幅位移激励下,测试了一汽车液压衬套的动刚度、滞后角随频率的变化特性。建立了液压衬套动态特性分析的非线性集总参数模型,基于模型,探讨了液压衬套橡胶主簧、惯性通道与液压衬套动特性之间的关系,计算结果与实验结果的一致,验证了计算模型分析的正确性。分析建立的集总参数模型,表明液压衬套在不同位移振幅激励下,存储动刚度具有不动特征点及在高频激励下动刚度趋于定值的特性。基于这种特性发展了模型参数的辨识方法,并对液压衬套集总参数模型中的参数进行了识别,利用识别得到的参数对液压衬套的动特性进行了计算,验证了识别得到的参数的正确性。 相似文献
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A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling. 相似文献
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Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue. 相似文献
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O'Brien RS 《Radiation protection dosimetry》2003,105(1-4):95-100
Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides. 相似文献
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Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995. 相似文献
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An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a
rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate
agreement is demonstrated between the derived relations and experimental data. 相似文献
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由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。 相似文献
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V. T. Kornienko 《Strength of Materials》1991,23(7):760-765
The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991. 相似文献
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M. M. Gadenin 《Inorganic Materials》2013,49(15):1352-1356
It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle. 相似文献
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V. T. Bublik A. I. Voronin E. A. Vygovskaya V. F. Ponomarev N. Yu. Tabachkova O. V. Toropova 《Inorganic Materials》2011,47(14):1563-1568
An analysis of anisotropy of the properties of a Bi2Se0.3Te2.7 solid solution was carried out using construction of demonstrative surfaces for thermoelectric effectiveness and thermal
expansion coefficients. It is shown that the texture is an important factor forming anisotropy of properties and technological
fitness of ingots for manufacturing modules. Anisotropy of properties based on the studies of the ingot textures obtained
using the float-zone method and Bridgman method (growing thermoelectric plates in a flat cavity) was studied. 相似文献