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考虑空气弹簧橡胶气囊力学特性,采用分数导数Kelvin-Voigt模型和摩擦模型对空气弹簧橡胶气囊进行建模;并基于牛顿力学、热力学、流体力学和黏弹性力学,建立了节流孔式空气阻尼系统非线性模型。在系统工作平衡点附近,建立了该系统的线性化模型,并基于复刚度等效得到了系统的等效刚度和等效阻尼系数方程。以某空气弹簧为研究对象,实验验证了等效模型的有效性。在此基础上,分析了激振振幅、激振频率以及关键设计参数对系统等效刚度和等效阻尼系数的影响规律,这为空气悬架的刚度和阻尼匹配设计提供参考。 相似文献
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该文给出了一类将二维和三维连续介质等效成弹簧元体系进行分析的研究思路,并将二维和三维的等效弹簧单元应用于容器结构与内部连续介质相互作用的静力与动力分析中。首先,该文给出了基于刚度等效原理的二维与三维等效弹簧元理论。其次,利用二维等效弹簧元模型作为基本单元分析了连续介质对容器壁的压力分布规律,并利用三维等效弹簧元模型分析了容器壁与内部连续介质共同响应的动力特性。数值算例表明:与常用的连续介质有限元模型相比,等效弹簧元模型的计算效率和精度更高。在容器结构与内部连续介质共同响应动力分析中,等效弹簧元体系与工程中常用的附加质量法相比,不光有更高的计算效率,而且能更正确地反映内部连续介质刚度对共同响应动力特性的影响。等效弹簧元在工程应用分析中具有良好的适应性。 相似文献
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欧拉-伯努利梁模型和一维弹簧振子模型是原子力显微镜(atomic force microscopy, AFM)的动力学理论基础。该文章提出了计算等效阻尼的新方法,并分别用挠曲线函数和一阶振型函数两种简化方式计算了由欧拉-伯努利梁模型简化为一维弹簧振子模型的等效质量、等效刚度和等效阻尼,并对两种简化方式进行了比较。在各项参数等效的基础上,进一步对固定端位移激励下悬臂梁的响应振幅进行了探讨。最后设计了无针尖探针远离样品处的扫频实验,实验表明用一阶振型函数简化所得的理论结果和实验吻合较好。该结果为原子力显微镜的动力学特性研究提供了理论参考。 相似文献
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基于功能结构的MEMS弹簧设计方法 总被引:2,自引:0,他引:2
平面微型弹簧是微机械电子系统(MEMS)中一种常用的弹性元件,其结构形状的不同将显著影响其刚度系数.针对在限定空间MEMS弹簧设计这一问题,提出了对弹簧进行结构分解和替换的设计方法.基于力学中的能量法得出了其功能结构形状与刚度系数的关系;理论分析结果表明,功能结构的替换可以实现在限定空间内弹簧刚度系数的改变.用有限元分析软件进行了仿真,其结果和理论分析吻合,验证了这一设计方法的正确性. 相似文献
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提出了一种优化的柔性环轮胎有限元建模方法,该方法在传统的径向弹簧支撑的柔性环模型上优化了弹簧的数量并采用B21线性梁单元等效胎体的变形。该研究应用万能试验机对哑铃型轮胎橡胶片进行单轴拉伸试验,得到了应力-应变曲线,采用有限元仿真软件Abaqus对材料拉伸数据进行了超弹性和黏弹性评估拟合,在自由状态及载荷状态下对普通子午线轮胎柔性环模型进行了线性摄动模态分析,并提取了振型与固有频率。通过与Singlemodle分析结果的对比,验证了此建模方法的有效性和准确性。该研究还应用该模型预测了在动力学条件下,速度、载荷、胎压对轮胎固有频率影响的规律,为轮胎结构分析和设计提供了参考。 相似文献
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《振动与冲击》2019,(21)
针对发动机空气弹簧液压悬置的动特性及其参数灵敏度影响,采用空气弹簧液压悬置上液室等效体积刚度替代解耦膜以及密闭空气腔对悬置动特性的影响,基于流体力学相关理论建立了空气弹簧液压悬置力学模型,并通过试验验证了该模型的正确性,分析了空气腔开启和关闭时空气弹簧的动态特性;采用该模型研究了空气弹簧液压悬置橡胶主簧体积刚度、阻尼系数、等效活塞面积、空气腔开启和关闭时上液室等效体积刚度、惯性通道液体惯性系数及阻尼系数等参数对悬置动刚度阻尼角的影响,获得了这些参数对空气弹簧液压悬置动刚度影响的灵敏度,该研究结果有助于空气弹簧液压悬置动特性的优化设计,缩短研发周期,节省研发成本。 相似文献
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基于有限元方法对高真空多层绝热(HV-MLI)低温管道进行多场耦合分析时,由于内管道波纹管几何及材料的非线性特性,使整个分析过程极为耗时,限制了有限元法在HV-MLI低温管道优化设计中的应用。为提高有限元分析效率,结合HV-MLI低温管道对所受载荷的响应特征,提出了用Combine14弹簧单元或等截面管等效替代波纹管的方法。通过对Combine14弹簧单元和等截面管相关参数的理论计算及定义,建立了两种HV-MLI低温管道内管的等效有限元计算模型,并对含波纹管、Combine14弹簧单元及等截面管内管道模型分别进行了有限元模拟计算,得到了各模型内管的应力及变形结果。结果表明:建立的两种等效模型合理、有效;与含波纹管模型相比,两种等效模型均在保证分析精度的同时,将分析效率提高了300倍;相比含Combine14弹簧单元模型,含等截面管模型在结构不连续处的应力集中程度较轻,且与含波纹管模型相符,更适于HV-MLI低温管道的多场耦合分析。 相似文献
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《材料与设计》2015
Compressive mechanical test and numerical simulation via finite element modeling have been employed on closed-cell copper-matrix nanocomposite foams reinforced by alumina particles. The FE analysis' purpose was to model the foam deformation behavior under compressive loading and to investigate the correlation between material characteristics and the compressive mechanical behavior. Exploring this, several foam samples with different conditions were manufactured and compression test was carried out on the samples. Scanning electron microscopy and image analysis have been performed on the foam samples to obtain the required data for the numerical simulation. The stress–strain curves exhibited plateau stress between 18 and 112.5 MPa and energy absorption in the range of 20.03–51.20 MJ/m3 for the foams with different relative densities. The foams exhibited enhanced mechanical properties to an optimum value, as a consequence of increasing the reinforcing nanoparticles, through both experimental tests and numerical simulation data. Also, the validated model of copper-matrix nanocomposite foams has been used to probe stress distribution in the foams. In addition, the results obtained by numerical simulation via ABAQUS CAE finite element modeling provided support for experimental test results. This confirmed that FEM is a favorable technique for predicting mechanical properties of nanocomposite copper foams. 相似文献
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A simulation study of the Friction Stir Spot Welding process for the lap-joining of thin aluminum sheets was carried out using the FEM code DEFORM 2D. The special feature of the developed FEM model is a 2D approach used for the simulation of a 3D problem, in order to guarantee a very simple and practical solution able to achieve results in a very short time. A set of experiments was performed by means of a CNC machine tool and FSSW lap joints on AA6060-T6 aluminum alloy plates were obtained. The experimental results were used as reference cases for the model validation. A set of tests was carried out by varying the process parameters, namely rotational speed, axial feed rate and plunging depth. Axial welding forces and temperature distribution in the joining region were recorded during the tests and their dependency from the welding parameters was studied. Shear tests were also performed to evaluate the quality of the joints as function of the welding conditions. A satisfactory matching between numerical and experimental data was found (average errors ranging around 10 %), confirming the good predictive ability of the FEM model. The FEM simulations were finally used for the prediction of the joint shear resistance. 相似文献
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目的采用有限元数值模拟方法研究空气垫在静态压缩时的力学性能,以便更直观、系统地了解空气垫的静态压缩力学行为。方法以柱状空气垫为对象,建立空气垫的静态压缩物理模型和力学模型,并基于该有限元模型模拟该结构的静态压缩过程,分析结构尺寸和充气压力对其静态缓冲性能的影响,得到空气垫在不同压缩量下的应力分布规律和变形特点。同时,将试验结果与模拟结果进行对比。结果空气垫的变形是从接触钢板的地方开始的,上下位置同时被压缩,有限元分析结果与试验结果吻合良好。结论所建立的有限元模型和数值模拟方法结果准确、合理。 相似文献
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Yanxia Du Guangming Xiao Yewei Gui Lei Liu Lina Zhang Mingxing Yu 《International Journal of Thermophysics》2014,35(8):1577-1589
The objective of the study was to investigate the heat transfer characteristics of a phase-change energy storage unit for thermal management. Considering the conduction in the solid and natural convection in the liquid, a physical and mathematical model for heat transfer was formulated. The governing conservation equations were solved using the finite-volume method on fixed grids. An enthalpy-porosity method was used for modeling the melting phenomenon of a phase-change energy storage unit. The time and space movement of the phase front, the temperature distribution, and the heat dissipation rate have been analyzed based on the model. The influence of the unit geometry, heat source location, and types of phase-change materials on the thermal performance of the energy storage unit were investigated. The model and numerical method were evaluated by comparing the numerical predictions with the experimental results. There was found to be excellent agreement between the calculation and experiment, indicating that the numerical method for heat transfer simulation of a phase-change energy storage unit is accurate. The results from the analysis elucidate the thermal performance of the phase-change energy storage unit and will provide the basis for the design and optimization of thermal management systems. 相似文献