大跨径小半径曲线桥梁转体结构设计

以宁波市轨道交通4号线工程跨铁路桥为例,阐述了大跨径小半径曲线转体桥转体结构的设计要点和应对此类桥梁上部结构恒载横向偏心的处理方法.通过Midas软件建模,计算分析了转体结构悬浇阶段的抗倾覆稳定性随悬浇节段的变化规律,并对转体阶段的结构稳定性计算进行了探讨.     

铝合金车轮重力铸造模具设计与分析

铝合金车轮与传统辐条式钢车轮相比,不仅外观多样化,其抗冲击性能及轻量化设计都得到了市场的认可和青睐,在生产铸造中,重力金属模铸造方式是每个生产企业的首选,生产出来的铝合金车轮要求无明显可见疏松、夹渣、气孔、针孔等铸造缺陷。     

发动机瞬时角速度波动分析

发动机在一定稳定工况下运转，瞬时转速会呈现一定的波动现象。本文介绍一种以发动机瞬时角速度的实时检测为基础，在一个工作循环内按着火顺序将做功冲程中瞬时角速度波动作为评价依据的判定发动机工作状况的方法。     

2×110kW推轮的设计及应用

为适应长江、汉江干支运输,本文设计了2×110KW推（拖）轮,介绍了该轮的主要数据及技术性能,并从船体艉部线型、浮心位置、螺旋桨及振动和噪声等方面作了改进,经使用其技术性能,从纵方式、建造质量等均达到了同类船型的先进水平。     

城市轻轨车辆及其相关技术的发展

从轻轨车辆总体结构、走行部及电传动等方面详细介绍了城市轻轨车辆的发展情况,其中包括低地板、独立旋转车轮和变流器等技术。同时介绍当前国外城市轻轨车辆的主要应用模式,分析未来城市轻轨车辆的发展趋势。     

Influence of the track quality and of the properties of the wheel–rail rolling contact on vehicle dynamics

This work describes an analytical approach to determine what degree of accuracy is required in the definition of the rail vehicle models used for dynamic simulations. This way it would be possible to know in advance how the results of simulations may be altered due to the existence of errors in the creation of rolling stock models, whilst also identifying their critical parameters. This would make it possible to maximise the time available to enhance dynamic analysis and focus efforts on factors that are strictly necessary. In particular, the parameters related both to the track quality and to the rolling contact were considered in this study. With this aim, a sensitivity analysis was performed to assess their influence on the vehicle dynamic behaviour. To do this, 72 dynamic simulations were performed modifying, one at a time, the track quality, the wheel–rail friction coefficient and the equivalent conicity of both new and worn wheels. Three values were assigned to each parameter, and two wear states were considered for each type of wheel, one for new wheels and another one for reprofiled wheels. After processing the results of these simulations, it was concluded that all the parameters considered show very high influence, though the friction coefficient shows the highest influence. Therefore, it is recommended to undertake any future simulation job with measured track geometry and track irregularities, measured wheel profiles and normative values of the wheel–rail friction coefficient.     

基于小波和自适应模糊神经的旋转设备故障诊断

针对传统的故障诊断方法和单独使用某一种智能诊断方法的局限性,将小波分析的故障特征提取方法和自适应模糊神经网络结合起来,对旋转设备的故障诊断进行了研究;通过对电机设备进行的故障诊断仿真实验,结果表明,与单独使用神经网路方法相比,该方法可以获得更高的故障诊断精度和诊断速度。     

基于增量谐波平衡法的汽车转向轮非线性摆振的研究

采用振幅作为控制参数,应用增量谐波平衡法,求得方程解的表达式,分析了系统的分岔和极限环振动现象,并用龙格库塔法进行数值计算验证,结果表明:增量谐波平衡法在汽车转向轮摆振分析中有效可靠,有足够的精度,并运用Floquet理论对周期解的稳定性进行分析,进而确定了极限环的稳定性,最后分析了各结构参数对摆振的影响。     

汽车镁合金车轮动态特性分析

与现行被广泛应用的铝合金相比,镁合金车轮能降低车辆质量和燃油消耗,减小车辆的振动和噪声,提高车辆的动力学特性。文中尝试采用新型铸造镁合金代替铝合金开发汽车车轮,并探索利用动态设计方法对某车型的车轮进行轻量化设计与分析,从而评价其强度可靠性及模态特性。     

一种旋挖钻机回转液压系统节能及控制方法研究

根据旋挖钻机上车回转部分的能耗、定位精度以及工作效率等三方面的要求,设计了回转液压系统和控制系统流程图,为旋挖钻机产品设计提供理论依据,对降低能耗具有一定的应用价值.