混合交通流理论模型构建与应用研究____论文.doc

混合交通流理论模型构建与应用研究 摘 要在桥梁的研究领域，以结构体系、受力性能的研究为主，对车辆荷载及其效应的研究相对较少。由于通过桥梁的车辆种类组成、行驶特征、荷载特性等方面都具有很强的随机性，导致运营车辆产生的荷载效应模拟非常复杂。交通流理论在描述车辆特性、行驶特征等方面较为成熟，本文引入交通流理论，力图更好地模拟分析运营车辆产生的桥梁荷载效应。 首先，在对混合交通参数分析的基础上，考虑超车换道流率，引入由沿程阻力和局部阻力两部分组成的粘性阻力项建立了车型比例与粘性系数的函数关系；基于流体动力学车流模型以及车辆跟驰模型，提出了一种流体动力学车流模型。在此基础上，求解了新模型的特征根，分析了平衡方程的超车换道率，进而构造了所建模型的差分格式，对速度和密度进行离散，分析了车流参数随时空的变化过程。最后，将混合交通流动力学模型与蒙特卡洛法相结合，在实测交通流量、车速、车型比例、轴距以及轴重等参数统计数据的基础上，运用MATLAB程序建立交通流参数的随机数组，计算了随机车流作用下的典型桥梁的运营车辆荷载效应。 关键词：交通流；跟驰模型；超车换道 Abstract In the field of bridge design, researches are mainly on the structural system and the mechanical properties, but relatively small on vehicle load and its effect. Due to the types, driving characteristics and load characteristics of the vehicles through bridge is random, the simulation of the load effect of operating vehicles is very complex. The traffic flow theory is quite mature in the description of the vehicle characteristics and driving characteristics. This paper introduces traffic flow theory to better simulate and analyze the effect of bridge load by operating vehicles. First, based on the analysis of the mixed traffic parameters, established the function of model proportion and viscosity coefficient. Considering the flow rate of overtaking and lane changing, introduced the viscous drag force composed of the resistance along the way and local resistance; a fluid dynamic traffic model is proposed based on fluid dynamic traffic model and vehicle following model. On this basis, this research solved the characteristic roots of the new model, analyzed the overtaking rate of the balance equation, and then constructed the difference scheme of the model. On this paper, the author analyzed the changing of traffic parameters over time and space by discrete the velocity and the density. Finally, combined the mixed traffic flow dynamics model with the Monte Carlo method, then applied the MATLAB program to establish traffic flow parameters random array and calculate the vehicle load effects