业务流程再造在汽车车身设计开发中的应用

介绍了业务流程再造的概念与定义,阐述了在汽车车身设计开发中进行业务流程再造的必要性和可行性,并简要介绍了业务流程再造中的几个关键技术,即如何设定与运作产品开发小组、车身成本设计与控制、车身质量设计与控制等。     

Fluid-structure coupled analysis of underwater cylindrical shells

Underwater cylindrical shell structures have been found a wide of application in many engineering fields, such as the element of marine, oil platforms, etc. The coupled vibration analysis is a hot issue for these underwater structures. The vibration characteristics of underwater structures are influenced not only by hydrodynamic pressure but also by hydrostatic pressure corresponding to different water depths. In this study, an acoustic finite element method was used to evaluate the underwater structures. Taken the hydrostatic pressure into account in terms of initial stress stiffness, an acoustical fluid-structure coupled analysis of underwater cylindrical shells has been made to study the effect of hydrodynamic pressures on natural frequency and sound radiation. By comparing with the frequencies obtained by the acoustic finite element method and by the added mass method based on the Bessel function, the validity of present analysis was checked. Finally, test samples of the sound radiation of stiffened cylindrical shells were acquired by a harmonic acoustic analysis. The results showed that hydrostatic pressure plays an important role in determining a large submerged body motion, and the characteristics of sound radiation change with water depth. Furthermore, the analysis methods and the results are of significant reference value for studies of other complicated submarine structures.     

插电式混合动力汽车碰撞安全性能设计开发

在对插电式混合动力汽车的发动机、燃油箱和动力电池、电机、高压电路等关键零部件进行相关的碰撞安全性能开发时,不仅需要考虑传统燃油车的碰撞安全标准要求,同时还要考虑电动汽车动力电池安全相关的碰撞标准要求和电安全设计防护.文章首先分析了相应的碰撞试验法规,结合上汽某插电式混合动力汽车整车布置方案,针对其特殊结构重点研究其追尾...     

基于交叉熵算法的电动车辆复合电源参数优化

为了提升电动汽车动力性能、降低车辆成本,以复合电源成本和车辆电耗最小为目标,通过交叉熵(crossentropy,CE)算法对车载复合电源的参数优化进行了研究.首先,以某款纯电动汽车为研究对象,根据能量与功率性能指标确定锂离子电池和超级电容的容量范围;其次,选取复合电源成本和车辆电耗建立多目标优化函数,并在ADVISOR环境中搭建车辆仿真模型;接着,采用CE算法,通过种群的不断迭代,更新高斯概率密度函数的均值和方差,找到复合电源参数的Pareto最优解集;最后,从最优Pareto解集中选取典型的匹配参数,分析复合电源成本、车辆电耗和整车性能.研究结果表明:在满足基本约束的前提下,得到了由100个解组成的Pareto最优解集.与第二代非劣排序遗传算法(non-dominated sorting genetic algorithm-Ⅱ,NSGA-Ⅱ)比较,CE算法有更好的收敛性与分布性;复合电源成本平均降低了9.49%,车辆电耗平均降低了22.81%;此外,城市道路循环工况(urban dynamometer driving schedule,UDDS)下车速误差最大值降低16.15%,整...