怀邵衡铁路沅江特大桥主桥设计

怀邵衡铁路沅江特大桥主桥为矮塔斜拉加劲连续梁组合结构,跨径为(90+180+90)m,采用塔、梁固结体系,综述该桥上部结构设计与计算。主梁采用单箱单室变截面混凝土箱梁;桥塔采用双柱式桥塔,塔高28 m;斜拉索为空间双索面体系,扇形布置。采用MIDAS Civil2006及BDAP程序对该桥进行结构计算分析,结果表明:该桥静力、稳定及动力特性均满足要求。     

浅析半刚性基层荷载型裂缝对路面结构的影响

半刚性基层裂缝的产生和发展很大原因是受到荷载作用,由交通荷载重复作用而造成的疲劳裂缝属于荷载型裂缝。文章结合广西路网工程建设实际状况,利用有限元计算模型分析半刚性基层受荷载作用开裂的情况,揭示基层荷载型裂缝对路面结构的影响。     

基于ANSYS的公路隧道衬砌结构安全分析

文章基于大型通用软件ANSYS,以深埋条件下隧道为例,采用荷载结构法,对考虑仰拱作用的各级围岩两车道公路隧道衬砌结构进行计算,求解其强度安全系数并进行相关安全分析,所得结论可为工程人员参考。     

Modeling the Car-Truck Interaction in a System-Optimal Dynamic Traffic Assignment Model

Several transportation problems, such as implementation of truck-only lanes, require understanding the interaction of heterogeneous dynamic traffic flows in order to provide accurate solutions. System-optimal dynamic traffic assignment can be modeled using a network loading procedure based on the cell transmission model, that is, the hydrodynamic wave model, and solved by linear programming. However, this framework cannot handle the asymmetric integration between the flow of trucks and cars. This article presents a novel formulation for network loading in system-optimal dynamic traffic assignment considering car–truck interactions. By using an embedded cell transmission model, this formulation incorporates a set of assumptions related to the kinematic characteristics of the flow of cars, trucks, and their interactions that can be solved using linear programming. We present numerical results supporting our modeling assumptions. Likewise, the observed emergent behavior captures the car–truck interactions accurately and indicates that minimum system-optimal travel time is obtained by encouraging cars to use highways with shorter distances.     

基于模型匹配控制的PHEV动态协调控制方法

在分析发动机与电动机的动态响应特性基础上,设计基于模型匹配控制的整车动力系统动态协调控制方法,并在所建立的并联式混合动力汽车(PHEV)的前向仿真模型上对该方法进行研究,证明该方法能有效控制2个动力源的动力耦合过程,具有较高的转矩控制精度和很好的动态响应特性,并利用所建立的硬件在环仿真试验台对该方法进行试验验证。     

贝雷架钢桥的静动力荷载试验研究

文章结合工程实例,通过对贝雷梁桥梁静动力荷载试验,指出贝雷架钢桥连接部分存在联系不够紧密、桥梁横向分配性较差、桥面的振动感觉明显及钢梁易锈蚀等问题。提出了改善贝雷架钢桥结构的力学性能和使用状况,加强结构的定期检查及监测等相关建议。     

A macroscopic theory for unsignalized intersections

The following paper presents a dynamic macroscopic model for unsignalized intersections which accounts for time-limited disruptions in the minor stream flow, even in free-flow conditions when the average flow demand is satisfied. It introduces a deterministic fictive traffic light to represent an average alternating sequence of available and busy time periods for insertion depending on the major stream flow. Two allocation schemes of the total outflow during green periods are developed to model the influence or non-influence of the minor stream over the major stream flow. The aggregation of the resulting dynamic flow variations gives relevant capacity values. Moreover, the model predicts accurate average vehicle delay and queue length estimates compared to theoretical and empirical data. It has three easy-to-measure parameters and can be integrated into a dynamic macroscopic simulation tool for urban networks.     

准双曲面齿轮传动的动载荷计算

本文以准双曲面齿轮传动系统为研究对象，考虑齿轮副在回转方向与各支承方向上的振动自由度，建立了齿轮系统的动力学模型，推导出它的运动微分方程，提出该参数激励方程组的求解方法，并进一步研究这一齿轮传动系统的激励特性，精确地计算出齿轮上的动载荷及各种转速下的动载系统。     

汽车车架动特性分析及应用

应用大型结构分析软件ＳＡＰ５Ｐ，对某车架者了有限元动态分析和实验模态分析，通过分析所提供的信息，对某客货车在使用中发生的故障进行了诊断，提出了相应的改进措施，从而使该车具有更好的动态性能。     

曲轴动平衡去重校正的计算

本文介绍曲轴动平衡去重校正的计算。由于去重形状复杂以及去重钻头不与曲轴轴心垂直,当校正面固定时去重重心不落在校正面上。解决办法是在实时计算时,多次调整校正面直至去重重心落在校正面上。