大坞电动绞车卷筒轴承损坏原因分析及解决方案

文章对大坞电动绞车卷筒轴承进行了受力分析，确定钢丝绳卷筒两侧的卷筒轴承受力不均匀是造成卷筒轴承易损坏的原因，提出了解决方案。并对电动绞车的使用、维修提出了建议，供同行借鉴。     

深水大跨码头结构研究

通过对我国港口现状的分析,对高桩码头上部结构改革状况的研究,提出了适应深水大跨要求的悬链线拱式纵梁码头结构型式。该结构能充分利用拱结构的跨越能力和钢筋混凝土的抗压性能,大幅度增加码头的排架间距,减少水下工程量,进而降低工程造价。与上海港洋山港区三期工程的普通纵梁结构相比,该结构排架间距可增大到28 m,基桩数量和水下施工工程量明显减少,工程造价降低23%。     

高桩承台靠船墩群桩水平受力简化分析

在船闸及河道中广泛应用的靠船墩、防撞墩等高桩承台结构承受较大的水平荷载,多采用群桩基础,而群桩受力分析比较复杂,有必要进行简化研究。以高桩承台靠船墩桩群为研究对象,分析了最不利工况,即撞击力作用通过靠船墩角点,且呈切线方向。通过典型的钢管桩三桩墩台进行分析,进一步推广到其他群桩结构,推导出简化公式。     

半船移位受力分析及运动仿真研究

通过ADAMS软件对运用垂直半串连造船法建造的半船移位到指定坞位的全过程进行仿真,优化运动轨迹。使用FLUENT、MAXSURF等软件系统建立半船实体受力分析模型,对半船移位过程中拖轮的牵引力和转矩随时间的变化进行计算,为实际移位提供了理论数据。     

水泥混凝土桥面力学响应影响因素分析研究

不同的桥面铺装结构参数、荷载形式、环境条件、桥梁跨径及层间接触条件等都会对沥青铺装层的力学响应产生影响,因此,有必要分析这些因素对水泥混凝土桥面铺装结构的应力应变状况的影响,为铺装层的设计和施工提供理论依据。     

接触网无交叉式线岔的工作原理与调整方法

针对国内准高速、高速铁路的快速发展及既有提速干线接触网改造的现状,阐述高速铁路接触网无交叉式线岔的工作原理及调整方法。     

Influence of tyre–road contact model on vehicle vibration response

The influence of the tyre–road contact model on the simulated vertical vibration response was analysed. Three contact models were compared: tyre–road point contact model, moving averaged profile and tyre-enveloping model. In total, 1600 real asphalt concrete and Portland cement concrete longitudinal road profiles were processed. The linear planar model of automobile with 12 degrees of freedom (DOF) was used. Five vibration responses as the measures of ride comfort, ride safety and dynamic load of cargo were investigated. The results were calculated as a function of vibration response, vehicle velocity, road quality and road surface type. The marked differences in the dynamic tyre forces and the negligible differences in the ride comfort quantities were observed among the tyre–road contact models. The seat acceleration response for three contact models and 331 DOF multibody model of the truck semi-trailer was compared with the measured response for a known profile of test section.     

京沪高速铁路先导段接触网原型系统设计

介绍了为进行高速铁路科技成果验证及最高运营时速试验而设置的京沪高速铁路先导段下行接触网原型系统的主要技术特征,对该系统的额定工作张力体系、导线及配套零部件、结构安装的优化设计等关键技术进行了论述。     

The role of the contact geometry in wheel–rail impact due to wheel flats: Part II

A classification of wheel flats according to the different stages of their growth is given, along with the characteristic features of the dynamic wheel–rail interaction for each category. Mathematical expressions and frequency spectra of the corresponding wheel mass trajectories are derived. Difference is made between the subcritical and the transcritical speed regime. A criterion is derived for contact loss for worn flats. Simulations show that the dynamic wheel–rail interaction is governed by the track stiffness for low train speeds or long flat lengths; for high speeds and/or short flat lengths the interaction is governed by the inertial properties of the wheel and the rail. For a given flat geometry, nonlinearities in the relationship between the impact magnitude and the train speed occur in the stiffness-dominated speed domain, whereas this relationship is approximately linear in the inertia-governed domain. In the latter domain, the impact magnitude is found to be linearly dependent upon the maximum trajectorial curvature or inversely linearly dependent on the minimum circumferential wheel tread curvature. The above relationships are valid for the subcritical speed regime, in which no contact loss occurs. Different contributions from the literature are compared with respect to the established relationship between impact magnitude and speed. Significant differences are found, due to insufficiently defined parameters and conditions. Conditions are derived for a consistent application of the so-called equivalent rail indentation in experiments with wheel flats, and the indirect strain registration method for measuring dynamic wheel–rail contact forces is reviewed.     

磁悬浮列车的涡流制动问题

介绍了磁悬浮列车制动的一般问题以及德国TR07磁悬浮列车中涡流装置的供电电源、制动装置、有关的计算与试验曲线。最后介绍了用“迎流”有限元法求解制动力的方法。