某乘用车侧面碰撞安全性仿真分析

为研究某乘用车型在发生侧面碰撞时是否满足国家安全标准,以有限元仿真为基础,对该乘用车进行侧面碰撞安全性分析.首先搭建整车侧面碰撞模型并设置计算参数;然后将模型的k文件导入到LS-DYNA软件中进行仿真计算;最后利用后处理软件观察整车碰撞时序图及B柱的变形模式,并参照国家侧面碰撞相关法规,发现该乘用车型存在B柱侵入量及侵...     

济南市顺河高架系杆拱桥吊杆更换设计

济南市顺河高架系杆拱桥跨越多股电气化铁路干线,跨径组成为1—90 m下承式钢管混凝土柔性系杆刚架拱桥,介绍该桥的吊杆更换设计。从3个方面介绍中小跨径系杆拱桥吊杆更换的设计思路:新吊杆结构型式选取、临时吊杆体系对比、电气化铁路上方更换吊杆施工注意事项。对施工监控、钢管混凝土脱粘、系杆松弛进行简单说明。模拟试验结果验证了该吊杆更换方法是可行的。     

汽油发动机电控喷射模拟试验装置的建立及其试验研究

根据汽车电控喷射系统喷油器结焦积炭形成机理，建立了一套有效的集汽油清净分散剂的评定与喷油器结焦积炭研究为一体的试验装置——电控喷射模拟试验装置。该装置通过对喷油器加热，控制喷油器的喷油时间间隔，从而强化了喷油器结焦积炭的形成条件，缩短了试验时间。试验表明，该装置对各种添加剂分辨效果明显，并验证了热浸在喷油器积炭形成中起关键的作用。     

基于磁流变阻尼器的半主动车辆座椅悬架模糊控制研究

设计基于磁流变阻尼器的半主动车辆座椅悬架系统的模糊控制器。用ADAMS对系统建立三维多刚体动力学模型,用MATLAB设计系统模糊控制器,并联合两者对整个系统进行仿真。仿真和台架试验结果表明,模糊控制策略能使该系统较好抑制垂直振动加速度,提高乘坐的舒适性。     

一种拉伸式的船用螺旋桨边界线逆向改型设计及其模拟仿真

依靠图谱和经验进行船用螺旋桨的设计已经不能适应时代的要求,运用数字化手段进行设计与制造已经成为当前的主要发展趋势。本研究创新了一种船用螺旋桨边界曲线改型方法,改型过程中通过移动导边侧约束面和随边约束面的位置来控制边界曲线的形状,从而实现螺旋桨的改型设计。通过fluent软件模拟,发现随边侧约束面沿拉伸方向的移动可以有效提高螺旋桨推进效率,最高可以达到53.2%,而导边侧约束面的移动在一个相对较小的范围内对螺旋桨效率的提高有明显的作用。因此,这种拉伸式的逆向改型方法对设计具有高效率的螺旋桨具有重要的应用价值。     

Development and validation of energy demand uncertainty model for electric city buses

The prediction of electric city bus energy demand is crucial in order to estimate operating costs and to size components such as the battery and charging systems. Unfortunately, there are unpredictable dynamic factors that can cause variation in the energy demand, particularly concerning driver choices and traffic levels. The impact of these factors on energy demand has been difficult to study since fast computing sufficiently accurate dynamic simulation models have been missing, properly quantified in terms of relevant inputs which contribute to energy demand. The objective is to develop and validate a novel electric city bus model for computing the energy demand, to study the nature and impact of various input factors. The developed equation-based model predicted real-world electric city bus energy consumption within 0.1% error. The most crucial unmeasurable input factors were the driven bus route, the number of stops, the elevation profile, the traffic level and the driving style. This understanding can be used to specify routes and stops for a given electric bus battery capacity. Worst-case scenarios are also necessary for electric bus sizing analysis. The best- and worst-case levels of the crucial factors were identified and with them synthetic best- and worst-case speed profiles were generated to demonstrate their effect to the energy demand. While the measured nominal consumption was 0.70 kWh/km, the computed range of variation was between 0.19 kWh/km and 1.34 kWh/km. For design sizing purposes, an electric city bus can have a broad range of possible energy consumption rates due to mission condition variations.     

A hybrid simulation-assignment modeling framework for crowd dynamics in large-scale pedestrian facilities

This paper presents a hybrid simulation-assignment modeling framework for studying crowd dynamics in large-scale pedestrian facilities. The proposed modeling framework judiciously manages the trade-off between ability to accurately capture congestion phenomena resulting from the pedestrians’ collective behavior and scalability to model large facilities. We present a novel modeling framework that integrates a dynamic simulation-assignment logic with a hybrid (two-layer or bi-resolution) representation of the facility. The top layer consists of a network representation of the facility, which enables modeling the pedestrians’ route planning decisions while performing their activities. The bottom layer consists of a high resolution Cellular Automata (CA) system for all open spaces, which enables modeling the pedestrians’ local maneuvers and movement decisions at a high level of detail. The model is applied to simulate the crowd dynamics in the ground floor of Al-Haram Al-Sharif Mosque in the City of Mecca, Saudi Arabia during the pilgrimage season. The analysis illustrates the model’s capability in accurately representing the observed congestion phenomena in the facility.     

Airport apron roundabout – Operational concept and capacity evaluation

The paper presents one of the initial steps in the evaluation process towards possible implementation of an innovative taxiway intersection design at Munich Airport apron. A roundabout is proposed as a potential solution for the 12-line intersection area expected at redesigned Apron 3. Although it is a common solution used in road transport for complex intersections, the roundabout has never previously been used for airport surface operations nor has its possible use been considered or analyzed. The paper presents preliminary design and operations concepts of the apron roundabout, followed by its capacity evaluation under Munich Airport operating conditions. The aim was to analyze whether a roundabout is suitable to replace a conventional intersection, in terms of capacity.     

HT—CVT油膜动力传递过程的仿真研究

为适应对车辆动力性能、经济性能和排放性能的要求,本文以HT—CVT为研究对象,建立了其动力传递油膜模型和油膜动力传递模型,通过计算分析得到了基于变速单元结构设计的油膜变化历程,以及油膜动力传递特征,结果与实验吻合较好。模型可直接应用于HT—CVT的计算机设计,计算结果对实际变速系统设计具有指导意义。     

船舶操纵模拟器操纵仿真数学模型

系统地论述了船舶操纵仿真数学模型。包括船舶操纵基本模型、水动力、螺旋桨推力及扭距、主机扭距、舵力及其力矩、风、浪、流、锚、缆、拖轮的作用力、浅水影响及侧壁效应,最后给出了主要仿真结果和主要结论