电动汽车防火安全策略研究

动力电池热失控是电动汽车安全事故的致命隐患,为了减少电池热失控而引发的一系列电动汽车自燃事故,文章对电动汽车自燃和电池热失控的机理进行分析,从电池包防火能力、电池热失控预警系统、整车非金属阻燃性能几个方面,来提升电动汽车的整车防火安全能力,并对电动汽车的防火安全提出了合理化建议。     

一种新型的度汛结构方案

本文结合工程实例及物理模型试验,提出灌浆块石护顶的度汛结构方案,经济且有效解决了施工期结构度汛安全的问题。     

基于百度云AI的自动售检票系统人脸识别应用可行性分析

人脸识别作为生物识别技术的重要分支,因其非接触性特点,在身份认证方面已经获得广泛应用。百度云AI作为智能云平台已经开放轻量级人脸识别和认证的应用服务。基于该服务不需要重复研发人脸识别算法,短期即可完成“刷脸”乘车环境搭建。分析了基于百度云AI(人工智能)技术快速建立轨道交通AFC(自动售检票)系统人脸身份识别应用场景的可行性。     

交通运输行业新能源汽车推广应用现状研究

近年来,在国家新能源汽车产业的战略引导下,我国新能源汽车产业加速发展,新能源汽车技术也得到了不断提高。本文对目前新能源道路运输车辆在交通运输行业中应用面临的问题进行了深入剖析,并从战略规划、车辆选型、车辆管理等方面,对完善交通运输行业新能源汽车应用的环境提出了意见和建议,为进一步保障新能源汽车安全运行、科学发展提供了有力支持。     

跨越V形峡谷桥梁多层介质效应的多点激励破坏模式

由于崎岖地形（非平坦地表和非均匀地层）具有复杂的地震动空间变异性,对于该类场地效应的地震特异性所引发的结构差动损害尚无系统性的研究。为了深入研究崎岖地形下地震动空间效应对结构的影响,针对多层非均匀介质V形峡谷这种特殊地形,详细分析了V形场地下地震动频谱特性的影响因素（行波效应、相干效应和局部场地效应等）,并模拟了相应的地震动输入;对一横跨V形峡谷的连续钢箱梁桥进行了有限元计算,对比分析了不同地震动输入和不同边界条件下结构模型的地震响应;探究了V形场地超大震作用下的桥梁破坏模式,计算出结构的薄弱部位,并着重对比了V形峡谷场地和平坦场地2种地形下的地震激励对结构破坏模式的影响差异,揭示了V形峡谷场地下的模拟多点地震输入特异性对桥梁的结构响应和破坏模式的特殊影响,发现同水平场地相比该类场地下的地震激励会在桥梁内部引发额外的差动内力,进而使桥梁破坏更早发生并改变了结构的破坏模式。结果表明：①V形峡谷场地极大地改变了地震波场中的散射波组成,且同水平场地地震激励相比,其对结构具有更强的空间差动效应,从而引发更大的差动内力;②与水平场地相比,V形峡谷场地地震动输入下的桥梁破坏发生时间较为提前,且初始破坏点并不相同,从而导致结构的破坏模式改变。     

On the overriding issue of train front end collision in rail vehicle dynamics

A three-dimensional dynamic model of crashed vehicles coupled with moving tracks is developed to research the dynamic behaviour of the train front end collision on tangent tracks. The three-dimensional dynamic model consists of a crashed vehicle model, moving track models, a simple wheel–rail contact model, a velocity-based coupler model and the model of energy absorption and anti-climbing devices. The vector method dealing with the nonlinear wheel–rail geometry is put forward in the paper. The developed model is applicable in the scope that central collisions occur on tangent tracks at low speeds. The examples of the vehicle impacting with a rigid wall and the train front end collision are carried out to obtain the dynamic responses of vehicles. The overriding issue is studied on the basis of the wheel rise in train collisions. The results show that the second bogie of the first colliding vehicle possesses the maximal wheel rise. The wheel rise increases with the increase of vehicles. However, the number of vehicles has tiny influence on the overriding in train collisions at low speeds. On the contrary, the impact speed has significant influence on the overriding in train collisions. The wheel rise increases rapidly if the impact speed is close to the critical speed of overriding. The large wheel rise is principally generated by the great coupler force related to the rigid impact in the axial direction.     

大型船舶平面分段智能车间的物流系统

目前,车间级的物流系统调度问题研究主要通过信息采集和现场监控解决,并没有通过优化算法进行实际分析。本文主要研究大型船舶平面分段智能车间的工件、物流设备的调度问题。首先将平面分段中的不同工位进行重组,同时将天车和卡车进行并行处理。其次引入有阻塞的混合流水线车间调度模型,搭建大型船舶平面分段智能车间物流系统的数学模型。最终基于粒子群优化算法(PSO),计算部件加工时间最短的数值仿真。     

Transient Dynamic Characteristics of a Non-Pneumatic Mechanical Elastic Wheel Rolling Over a Ditch

The transient dynamic characteristic of a tire, which has a significant effect on vehicle handling stability and ride comfort, is difficult to study in detail because of its highly non-linear behavior. In this study, the transient dynamic characteristics of a non-pneumatic wheel, called the mechanical elastic wheel (MEW), which was rolling over a ditch were investigated by the explicit dynamic finite element (FE) method. A three-dimensional FE model of MEW considering geometric nonlinearity, material nonlinearity and large contact deformation between the wheel and the road, was established. For the validation of the accuracy and reliability of the FE model of MEW, the simulation and the experimental results of the radial stiffness and footprint of MEW were compared and analyzed. A dynamic simulation of the validated FE model of MEW rolling over a ditch was conducted using the ABAQUS/Explicit program. The equivalent stress and the contact stress generated during the process of the rolling MEW impacting the ditch were studied in detail. The effect of the rolling speed on the transient dynamic characteristics was also analyzed based on the simulation results. The simulation results could provide guidance for the optimization of the MEW structure and vehicle dynamics.     

Enhancing the Efficiencies of Organic Photovoltaic and Organic Light-Emitting Diode Devices by Regular Nano-Wrinkle Patterns

Organic photovoltaic (OPV) cells and organic light-emitting diodes (OLEDs) are energy harvesting and generation devices that have attracted great attention these years because of their low costs, thin film structures, flexibility and environment-friendly manufacturing processes. For such thin film devices, photon management methods that increase the light absorption of OPV cells and the light extraction from OLEDs are highly desirable. Here, we report the experimental efforts to fabricate geometrically tunable and spontaneously formed nano-wrinkle structures with large areas, and the theoretical results on photon management with the nano-wrinkles.