基于禁忌算法的多约束集装箱装载问题研究

多约束集装箱装载问题的约束主要包括集装箱重心位置约束、集装箱单箱重量约束、货物放置顺序约束、货物摆放方位约束以及货物摆放位置约束。采用禁忌算法求解该问题。算法基于自然数编码,设计了货物的摆放规则和序列生成方式,设定二种邻域,根据邻域的不同,构造了两种禁忌表。针对算法的原理,分析了具有代表性算例的试验结果,表明了所提出的禁忌算法对优化多约束集装箱装载问题的有效性。     

轮机资源管理中情景意识对安全的影响

文章在概述轮机资源管理基本概念的基础上,结合轮机案例分析阐述情景意识对轮机安全的重要影响,并提出维持良好情景意识是预防和控制事故发生的有效措施。     

砰击载荷下轻质波纹夹芯夹层板动力响应特性分析

文章对轻质波纹夹芯夹层板(Light Weight Corrugated-Core Sandwich Plates,LWCCSP)在不同入水速度下(1-6 m/s)的流-固耦合非线性动力学行为进行了分析。建立了气—液—固三相数值模型,通过显式动力求解获得了轻质波纹夹芯夹层板砰击压力的分布特点及结构变形规律,并与同等质量的加筋板在流固砰击下的非线性力学行为进行了对比,并研究了轻质波纹夹芯夹层板主要设计参数对其砰击响应的影响。研究结果表明,轻质波纹夹芯夹层板较同等质量的加筋板表现出更好的抗砰击性能;下面板厚度、芯层厚度的增加在一定范围内可以有效提高轻质波纹夹芯夹层板的抗砰击性能。     

Effect of the front and rear weight distribution ratio of a Formula car during maximum-speed cornering on a circuit

Because Formula cars are lighter than ordinary cars, the optimal settings for this type of car are thought to be different from those of a ordinary car. The front and rear weight distribution ratio of a vehicle is an important parameter that exerts a significant influence on critical cornering. The tendency of a ordinary car to under-steer during critical cornering is determined by the front and rear weight distribution ratio of the vehicle. Specifically, when the front of an ordinary FR (front-engine, rear wheel drive) vehicle is slightly heavier than the rear, the car tends to understeer during critical cornering. However, the optimal weight distribution ratio for critical cornering is not obvious for a formula car because of its lightness. This observation was investigated using a driving course similar to a real driving course to perform a maximum speed cornering simulations. It was found that a front to rear weight distribution ratio of 40:60 resulted in the fastest lap time. This ratio also gave the best results in the maximum-speed driving experiment performed using a driving simulator. Moreover, the maximum lateral acceleration during turning, the driving force, and the load movement of the inside and outside wheels was calculated using experimental driving force data and the concept of a tire friction circle. As a result, driving mechanics have been determined for a vehicle having a front/rear weight distribution ratio of 40:60 while traveling at maximum speed.     

Effect of structural variables on automotive body bumper impact beam

Increasing fuel economy has been a central issue in the development of new cars, and one of the important strategies to improve fuel economy is to decrease vehicle weight. In order to obtain this goal, researchers have sought to make bumpers lighter without sacrificing strength, ability to absorb impact, or passenger safety. In this study, the effects of structural variables on the torsional stiffness of a body bumper impact beam were analyzed for possible weight reduction. To this end, the effects of variation of section height, increase of impact beam thickness and the addition of stays in a bumper impact beam were carefully investigated and compared. Among these, the most effective way to increase the torsional stiffness of the bumper impact beam was found to be increasing the section height. In addition, the potential for overall weight reduction of the impact beam was examined by comparing the crash capability of a bumper using conventional steels with that of high-strength steel (boron steel) with a tensile strength of 1.5 GPa. This analysis could serve as a guide to design for optimal bumper impact beam development.     

汽车电子制动系统——电子稳定程序ESP

电子稳定性控制系统整合了多项电子制动技术,是主动安全系统的一项技术突破．推广应用十分迅速。本文重点阐述德国博世公司ESP系统的各项电子制动技术、典型工况、组成和工作原理,并分析了故障诊断思路。     

电动汽车空调系统解决方案

为了保持电动汽车的舒适性,本文探讨了电动汽车空调系统的几种解决方案,分别对电动空调系统、电驱动压缩机系统、座椅空调系统以及冰水冷媒制冷系统进行了介绍。对于电动空调系统,分别介绍了电动热泵式空调系统、电动压缩机制冷与电加热器制热混合调节空调系统。     

PFWD在路基强度评价中的应用

对太澳高速公路在建路基17、18和19标段进行了PFWD和FWD测试,PFWD和不同吨位FWD测得的中心弯沉与荷载的变化曲线的形状基本相似,三个标段的PFWD和FWD平均弯沉和平均荷载大致呈直线分布,两法反演得到的路基回弹模量也基本接近,这说明PFWD测得的弯沉是准确的,可用于评价和检测公路路基强度。     

层次分析法对公路建设项目环境影响综合评价的应用研究

运用层次分析法,针对公路工程在施工期间对沿线环境影响的实际情况,建立了基于层次分析法的综合评价模型,并对公路沿线地下水环境的影响的实际应用进行了实例分析,为保护公路沿线水环境的质量提供可靠的决策依据。     

沥青混凝土路面现场热再生方法的适用性分析

沥青混凝土路面现场热再生技术（HIR）分为三类：表面再生、复拌再生与重铺再生,不同的工艺有其各自的适用条件,应通过详细的路面破损评价,对旧沥青路面材料进行相关指标的测试,综合考虑交通控制方案、施工条件以及环境因素,结合实际路况和再生设备条件对HIR的适用性进行分析评定,以便采取科学合理的再生方法。