发动机曲轴系非线性动力学分析

针对发动机曲轴系振动与主轴承油膜耦合问题，采用模态减缩法，将曲轴系中每个部件压缩为缩减自由度的子结构模型，并通过不同的连接体对它们进行连接，构成发动机曲轴系的非线性动力学模型，求解该模型，即可得到曲轴的动力学特性与主轴承油膜特性。本文以某四缸发动机为例，采用以上流程对其曲轴系进行非线性动力学仿真分析。计算结果表明，该发动机的曲轴系振动符合设计要求，且对于主轴承轴瓦磨损的预测与试验结果吻合，说明了曲轴系动力学仿真计算的正确性。     

基于齿轮非线性动力学的变速器异响分析

从非线性动力学的角度对某变速器齿轮异响故障进行分析,针对异响的表现特征对单对齿轮副间隙非线性振动问题进行研究,从影响齿轮非线性动力响应特征的激励频率、载荷比、阻尼比等参数出发分析系统稳定的条件,并根据分析所得的结论对变速器异响问题的改进提出建议。     

汽车转鼓试验非线性动力学特性与影响因素分析

针对道路试验车辆和转鼓试验车辆分别建立了非线性动力学分析模型,通过仿真结果的对比分析阐明了转鼓试验可能导致的误差,进而通过对转鼓试验系统中车辆固定方式、非驱动轮胎固定方式、转鼓模拟转动惯量和动态响应控制标准的灵敏度仿真分析,指出了影响转鼓试验模拟精度的关键因素,提出了动态响应的改进和控制措施.     

基于ITS的物流园区协同非线性动力学模型

物流园区是物流产业协同的重要表现形式。研究园区企业的迁移规律和建立迁移模型，对于稳定企业、协同发展及对于政府制定相应的园区政策，吸引企业入驻具有重要的意义。文中构建了物流园区的态度空间和物流产业构形，建立了园区物流企业迁移的非线性动力学模型。以武汉丹水池物流园区为例，分析了园区聚集企业的特点和规律，证明了该模型的有效性，此方法可用于指导物流园区的建设。     

载荷比对齿轮间隙非线性系统动力学行为影响的研究

文中建立了圆柱直齿轮间隙非线性系统动力学模型,综合考虑了齿轮沿基圆切向综合误差、轴承和齿侧间隙及时变啮合刚度,采用单自由度间隙非线性时变模型,分析了在不同载荷下齿轮由周期运动向混沌运动的转变,说明了载荷比对齿轮间隙非线性系统动力学行为的影响。     

汽车变速器齿轮系统动力学行为分析

以单对渐开线直齿圆柱齿轮传动为例,对汽车变速器齿轮非线性动力学建模及其动力学行为分析方法进行了研究,分析了随着齿轮副激励频率、载荷比、阻尼比等参数变化系统周期解结构的变化情况,相关方法和结论对于更好地掌握变速器齿轮动态特性,以及更好地对变速器进行NVH控制有指导意义。     

桥面铺装非线性瞬态温度场分析

桥面温度场属于非线性瞬态温度场,其微分方程难于求得解析解。该文通过对进入桥面的对流换热、太阳辐射及辐射换热等方面进行全面分析,采用有限元按平面问题进行了瞬态温度场的计算,并与实测结果比较,结果表明,在正确掌握边界条件、桥面材料特性参数及本地区气候条件的情况下,能够可靠地计算出不同位置、不同时间桥面结构的温度分布,并进行温度应力的计算。     

摊铺机压实机构的一种非线性动力学理论研究

借助３自由度的摊铺机压实机构的非线性动力学模型，研究了该压实机构中的有关部件的振动规律，分析了构成这些振动信号的有关成分随激振频率、激振力大小以及熨平板平台自身重量等变化而变化的规律，这些对摊铺的开发研制等具有重要的参考价值。     

考虑塑性变形的振动压路机非线性动力学仿真

借助于土壤变形的一种塑性模式，提出了一种振动压路机压实过程的非线性动力学模型。在此基础上，借助计算机技术，探讨了振动压实中机架与振动轮的运动规律，并对激振力减少、土壤刚度变大和塑性变形增大等情况进行了仿真研究，发现了一些对压路机设计有参考价值的新现象     

电动车电机轴承转子系统弱非线性主共振分析

以电动车电动机轴承转子系统为研究对象,考虑转子系统受不平衡磁拉力、油膜力、偏心力、阻尼力以及非对称刚度等因素的影响。应用牛顿第二定律建立电动机轴承转子系统的弱非线性振动方程模型,应用求解非线性方程的平均法,得到系统主共振的幅频响应方程。并分析电磁参数对系统主共振幅频响应曲线的影响,随着转子半径、气密磁隙和铁芯长度的增加,系统的幅频响应曲线均向右偏移。     

惯性荷载和地震荷载作用下单桩横向非线性动力响应简化分析

根据已建立的地基土—单桩系统横向非线性动力响应简化分析模型和计算方法,讨论了动力荷载作用下单桩横向非线性惯性响应以及地震作用下单桩横向非线性运动响应,采用两个非线性运动响应因子表征地基土—单桩系统运动响应的非线性特性。计算结果表明:该模型不仅能够模拟在(准)静态单调循环荷载和简谐荷载作用下的单桩横向非线性惯性响应,而且可以反映地震过程中地基土—单桩系统横向非线性运动响应的基本特征。     

Dual objective active suspension system based on a novel nonlinear disturbance compensator

This paper proposes an active suspension system to fulfil the dual objective of improving ride comfort while trying to keep the suspension deflection within the limits of the rattle space. The scheme is based on a novel nonlinear disturbance compensator which employs a nonlinear function of the suspension deflection. The scheme is analysed and validated by simulation and experimentation on a laboratory setup. The performance is compared with a passive suspension system for a variety of road profiles.     

Novel electronic braking system design for EVS based on constrained nonlinear hierarchical control

Both environment protection and energy saving have attracted more and more attention in the electric vehicles (EVs) field. In fact, regarding control performance, electric motor has more advantages over conventional internal combustion engine. To decouple the interaction force between vehicle and various coordinating and integrating active control subsystems and estimate the real-time friction force for Advanced Emergency Braking System (AEBS), this paper’s primary intention is uniform distribution of longitudinal tire-road friction force and control strategy for a Novel Anti-lock Braking System (Nov- ABS) which is designed to estimate and track not only any tire-road friction force, but the maximum tire-road friction force, based on the Anti-Lock Braking System (ABS). The longitudinal tire-road friction force is computed through real-time measurement of breaking force and angular acceleration of wheels. The Magic Formula Tire Model can be expressed by the reference model. The evolution of the tire-road friction is described by the constrained active-set SQP algorithm with regard to wheel slip, and as a result, it is feasible to identify the key parameters of the Magic Formula Tire Model. Accordingly, Inverse Quadratic Interpolation method is a proper way to estimate the desired wheel slip in regards to the reference of tireroad friction force from the top layer. Then, this paper adapts the Nonlinear Sliding Mode Control method to construct proposed Nov-ABS. According to the simulation results, the objective control strategy turns out to be feasible and satisfactory.     

沥青混合料粘弹特性分析

选择沥青混合料AC-13C,通过UTM进行室内静态蠕变试验,用线粘弹本构模型Burgers模型进行粘弹特性分析,并通过构建经验的双曲线和幂函数进行数据拟合,发现尽管Burgers模型物理意义比较清晰,但其精度较经验本构模型低。因而在对于描述沥青混合料本构特点时,经验本构方程是比较适用的。     

大跨径斜拉桥非线性静风稳定性全过程分析

在综合考虑静风荷载与结构非线性性影响的基础上，采用增量与内外两重迭代相结合的方法对大跨径斜拉桥静风稳定性进行了全过程分析。以一座主跨１０００ｍ的斜拉桥为例，验证了该方法的可行性。最后，探讨了初始攻角、斜拉索的垂度效应等因素对大跨径斜拉桥静风稳定性和影响。     

Vehicle modeling with nonlinear tires for vehicle stability analysis

The dynamic stability of a vehicle depends on various maneuvering features, such as traction, braking, and cornering. This study presents nonlinear vehicle models for estimating the stability region and simulating the dynamic behavior of a vehicle. Two types of vehicle models were found by considering the degrees of freedom and linearity. A simple model with nonlinear tire dynamics is useful for determining the stability region, while a complex model (a multi-body dynamic model in MSC.ADAMS) is appropriate for carrying out accurate simulations. Actual data for a mid-sized passenger car were used, and the models were validated by comparison with test results.     

Performance investigation of vehicle suspension system with nonlinear ball-screw inerter

This paper investigates the influence of ball-screw inerter nonlinearities on the vibration isolation performance of the vehicle suspension system. That is achieved by building a nonlinear mechanics model of the ball-screw inerter with friction in ball-screw assembly and elastic effect of screw. The parameters of the nonlinear mechanics model are identified using recursive least squares algorithm based on test data. Then, the nonlinear ball-screw inerter is applied to vehicle suspension analysis of the half-car model with three passive suspension layouts. The performance of the vehicle suspension system with the nonlinear ball-screw inerter is compared with that with the linear inerter. It is demonstrated from the results that the vibration isolation performance of the vehicle suspension system is slightly influenced by considering the ball-screw inerter nonlinearities in general. The influence of the ball-screw inerter nonlinearities on every performance indicator for different suspension layouts is discussed finally.     

沥青路面结构非线性分析的现状与展望

阐述了沥青路面所用材料的分类及基本特性,介绍了国内沥青路面结构非线性分析的现状,给出了各类材料在路面受力分析中所用的本构关系,说明了沥青路面结构非线性分析的重要意义与广阔前景。     

天然状态下路堤地基破坏模式分析

利用有限元模拟路堤地基在路堤载荷作用下的破坏情况,分析单一地基物理力学参数变化对地基破坏模式的影响,为利用地基破坏模式推导出路堤地基极限承载力的理论计算公式提供依据。