汽车用空气弹簧横向刚度的静态有限元分析

文中建立了空气弹簧的静态有限元模型。运用有限元分析软件在充分考虑材料非线性、几何非线性和状态非线性的条件下,分析了在不同情况下空气弹簧的变形情况以及静刚度等性能的变化。得到了空气弹簧横向刚度特性的曲线图。由模拟刚度特性曲线可知,空气弹簧的横向刚度随着帘线角和压力的增大而增大,呈非线性特征,且随着帘线角的增大,横向刚度趋于线性。     

铰接式自卸车平衡悬架系统橡胶弹簧刚度的非线性特性分析与优化

为了提高AD250铰接式自卸车的平顺性,对其平衡悬架夹层橡胶弹簧的刚度进行了分析和优化.建立了橡胶弹簧的参数化有限元接触模型,对弹簧轴向刚度的非线性特性进行了分析,分析结果与实验结果能很好地吻合.研究结果表明, 此橡胶弹簧刚度偏大且非线性特性不能满足悬架在不同载荷下具有等固有频率的要求,为此以固有频率2Hz为优化目标对橡胶弹簧的参数进行了优化,优化后的橡胶弹簧能使车辆保持稳定且良好的平顺性.     

橡胶复合型弹簧的非线性刚度分析

通过运用非线性有限元方法，对橡胶复合型弹簧的刚度特性进行了计算分析，分析中考虑了橡胶材料的非线性特征以及橡胶弹簧接触时的非线性机理。讨论了不同橡胶材料对橡胶复合型弹簧刚度的特性的影响，为不同用途的橡胶复合型弹簧的合理设计，提供了较为精确的方法和依据。     

基于MSC.Marc的中凸螺旋弹簧刚度特性研究

以帕萨特B5后悬中凸圆柱螺旋弹簧为例,基于大型有限元分析软件MSC.Marc进行刚度特性仿真分析,研究了中凸螺旋弹簧的静、动态特性,并通过试验相佐证.证实了弹簧刚度存在显著的非线性,得到了弹簧静刚度的非线性拟合公式;证实了非线性中凸弹簧刚度与激振频率存在密切关系,并得到了中凸螺旋弹簧随频率变化而变化的动刚度曲线.最后,本文证实了预载荷对中凸螺旋弹簧动刚度有显著影响.     

异形汽车座椅弹簧的刚度及应力分析

以某型异形汽车椅弹簧为研究对象,针对其刚度特性及应力进行理论计算.利用Hypermesh与ANSYS联合仿真研究该异形汽车座椅弹簧的结构特点,并对其弹簧的刚度特性进行应力分析和强度校核.结果表明:基于弹簧串联理论得到的弹簧刚度和仿真结果更接近;汽车座椅弹簧轴向载荷与轴向变形量呈近似线性关系,刚度随着轴向力的增大而小幅增大,在满载工况下,汽车椅弹簧能满足强度要求,符合实际应用要求.利用有限元软件对弹簧进行应力分析及强度校核,并对切应力计算公式提出修正系数,使结果更加合理.     

两种拖拉机安全防护架的非线性有限元分析

根据拖拉机安全防护架强度试验标准，安全防护架在试验载荷下发生大变形，几何非线性和材料非线性问题必须考虑．本文根据线性分析结果，进一步对安全防护架进行了非线性有限元计算，分析其强度和刚度．模型实验及其计算结果吻合，表明计算程序和方法是可行的．     

葡萄力学模型的研究及对压缩载荷的响应分析

根据葡萄结构特点,以二维问题为研究对象,建立了葡萄力学模型.提出了用数值模拟与实验相结合确定模型力学参数和用线性拟合实验数据确定物体刚度的方法.用有限元方法和MATLAB计算软件研究了葡萄压缩时内压改变量、压缩外力、压缩变形量和皮的应力之间的关系,给出了关系曲线图.得出了葡萄在压缩情况下,总体变形量与压缩外力、内压改变量和皮的应力的关系是非线性关系.但葡萄内压改变量与压缩外力和皮的应力的关系以及皮应力与压缩外力的关系是近似的线性关系.葡萄体积改变量随压缩外力的增加而成线性的增加.葡萄首先在不受力的表皮破裂等5点结论.图6,表2,参8.     

基于空气弹簧非线性横向刚度的高速客车动力学仿真

运用非线性有限元分析技术，研究了由多层正交异性复合材料组成的高速客车空气弹簧的非线性横向刚度特性，分析考虑了大变形的几何非线性和胶囊与金属裙板形成的接触非线性，得到了空气弹簧横向刚度非线性特性较为精确的描述，基于这一横向刚度，对安装空气弹簧的高速客车转向架进行了非线性暂态曲线通过的动力学仿真，获得了较为精确的结果。     

受边界约束的薄圆橡胶片的压缩和剪切特性

提出了一种计算上下两面受约束的薄圆橡胶片在竖向压力作用下的压缩刚度和剪应变分布的近似公式 ,讨论了中间开小圆孔的圆形橡胶片的力学性能 ,运用标准有限元程序STRAND 6分析了不同类型的薄圆橡胶片的压缩和剪切特性 .理论分析和有限元数值结果的比较说明了所提出的近似公式是可行的     

不同摩擦系数的少片变截面钢板弹簧性能分析

采用不同材料的板簧垫片,簧片间摩擦系数亦有所不同,因此设计钢板弹簧时仅考虑钢与钢的接触摩擦将造成其性能分析结果的不准确.针对这一问题,利用ANSYS软件的接触非线性功能,对少片变截面钢板弹簧的等效应力及刚度特性进行分析,得到不同摩擦系数下的VonMises应力分布和载荷-变形曲线,重点讨论了摩擦系数对钢板弹簧应力及刚度特性的影响;同时对钢板弹簧进行相应的性能试验.结果表明:少片变截面钢板弹簧的应力计算值和测试值误差较小,刚度仿真计算值和试验测量值基本吻合,相对误差小于5%,说明有限元分析能精确地模拟各簧片间的接触和摩擦问题,真实反映钢板弹簧的受力和变形情况,可用于研究簧片间不同摩擦系数对钢板弹簧应力及刚度特性的影响.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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