基于RECURDYN的某厢式货车多工况平顺性分析与优化

发布时间：2018-03-17 16:04

本文选题：厢式货车　切入点：钢板弹簧　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着汽车工业的飞速发展,许多企业对商用车的开发已从满足基本的运输需求转向对行驶平顺性和操纵稳定性等更高性能的追求。厢式货车作为最常见的物流运输车辆,在长距离行驶过程中,更应注重车辆的行驶平顺性,缓解驾乘人员的疲劳,确保驾驶安全性。本课题结合某企业对某厢式货车平顺性改进项目,应用多体动力学软件RecurDyn建立整车动力学模型并对模型中影响行驶平顺性的参数进行分析和优化。首先,介绍汽车平顺性的国内外研究现状及钢板弹簧建模方法,包括有限元法、离散梁法、中性面法及三连杆法。详细介绍RecurDyn软件的基本理论,包括:相对坐标系统、相对坐标运动学方程、函数表达式、元模型优化算法和二次开发。采用SAE三连杆法在RecurDyn中建立钢板弹簧动力学模型。考虑实际钢板弹簧工作时,由于各簧片间摩擦接触产生的迟滞特性,提出在连杆旋转副中引入Sliding摩擦力学模型,模拟各簧片间的接触摩擦;为确保所建模型的力学特性与实际相符,采用DOE实验分析找出影响钢板弹簧刚度特性和迟滞特性的主要参数;建立钢板弹簧有限元模型,以仿真获得的时间-位移曲线为目标曲线,利用元模型优化算法,对选定的参数进行辩识,获得满足设计要求的钢板弹簧三连杆模型。对整车模型进行分析,在RecurDyn中建立驾驶室、车厢、前后悬架总成及轮胎模型的各个子系统,单独调试后根据各子系统间的约束关系进行装配,得到整车动力学模型。为提高整车平顺性仿真效率,对脉冲路面和随机路面进行适当简化,之后分别进行脉冲路面和随机路面激励下不同车速的平顺性仿真。对实际样车进行脉冲路面和随机路面行驶条件下不同车速的道路平顺性试验,对比仿真结果,验证仿真模型的正确性。以所建整车动力学模型为样机,采用DOE实验分析,分析悬架参数及驾驶室悬置参数对平顺性的影响趋势,确定平顺性优化时各设计变量的取值范围;以悬架偏频、悬架动挠度及车轮相对地面动载荷为约束条件;参照GB/T 4970-2009《汽车平顺性试验方法》,以驾驶室地板垂向加权加速度均方根值为优化的目标函数,并基于C#语言在RecurDyn/ProcessNET二次开发环境中编写其计算程序;采用元模型优化算法对整车模型进行优化,为该厢式货车的平顺性改进提出参考方案。
[Abstract]:With the rapid development of automobile industry, the development of commercial vehicle in many enterprises has changed from meeting the basic transportation demand to the pursuit of higher performance, such as ride comfort and handling stability. In the long distance driving process, we should pay more attention to the ride comfort of the vehicle, alleviate the fatigue of the driver and ensure the driving safety. The multi-body dynamics software RecurDyn is used to establish the vehicle dynamics model, and the parameters affecting the ride comfort in the model are analyzed and optimized. Firstly, the domestic and foreign research status of vehicle ride comfort and the method of leaf spring modeling, including finite element method, are introduced. Discrete beam method, neutral plane method and three-link method. The basic theory of RecurDyn software is introduced in detail, including: relative coordinate system, relative coordinate kinematics equation, function expression, Element model optimization algorithm and secondary development. The dynamic model of leaf spring is established in RecurDyn by using SAE three-link method. Considering the hysteresis characteristics of the actual leaf spring due to friction contact between the spring and the spring, the dynamic model of the leaf spring is established by using the three-link method of SAE. In order to ensure that the mechanical properties of the model are in accordance with the practice, a Sliding tribological model is introduced to simulate the contact friction between the Reed and the spring in the rotating pair of connecting rod. The main parameters affecting the stiffness and hysteresis characteristics of leaf spring are found out by DOE experiment, and the finite element model of leaf spring is established. The time-displacement curve obtained by simulation is taken as the target curve, and the optimization algorithm of element model is used. Identify the selected parameters, obtain the three-link model of leaf spring which meets the design requirements, analyze the model of the whole vehicle, set up each subsystem of cab, carriage, front and rear suspension assembly and tire model in RecurDyn. In order to improve the simulation efficiency of vehicle ride comfort, the pulse road surface and the random road surface are properly simplified, and the dynamic model of the whole vehicle is obtained by assembling according to the constraint relation among the subsystems. After that, the simulation of the ride comfort of different vehicle speeds under impulse and random pavement excitation is carried out, and the road ride comfort test of the actual sample vehicle is carried out under the conditions of pulse road surface and random road surface, and the simulation results are compared. The validity of the simulation model is verified. Taking the dynamic model of the whole vehicle as a prototype, the influence trend of suspension parameters and cab mounting parameters on ride comfort is analyzed by using DOE experimental analysis, and the value range of each design variable when the ride comfort is optimized is determined. Taking suspension bias frequency, suspension dynamic deflection and wheel relative ground dynamic load as constraint conditions, referring to GB/T 4970-2009 < vehicle ride comfort test method], taking the root mean square value of vertical weighted acceleration of cab floor as the optimized objective function, Based on C # language, the calculation program is compiled in RecurDyn/ProcessNET secondary development environment, and the optimization algorithm of metamodel is used to optimize the whole vehicle model, which provides a reference scheme for improving the ride comfort of the van.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U461.4

【参考文献】