高速公路机电工程联合设计阶段方案的优化

结合西部开发省际公路通道重庆至长沙公路武隆至水江段高速公路机电工程联合设计的具体情况,探讨了如何根据工程的实际情况,有针对性地进行联合设计阶段的方案优化。     

基于虚拟样机技术的轴系动力仿真及优化

应用I—DEAS软件的CAD模块和多刚体动力学仿真软件ADAMS,构造了提速机车16V柴油机轴系的虚拟样机模型。在进行了运动分析和动力学分析之后,从优化设计的角度实现了动不平衡力最小的优化设计,仿真及优化结果对改善轴系振动是重要的。     

双横臂独立悬架ADAMS建模及运动特性分析

利用ADAMS建立了某轻型车完整的双横臂独立悬架运动学仿真模型,为反映车辆的真实行驶工况,对左、右车轮测试平台分别创建了随机激励。通过仿真分析,揭示了运动特性参数在悬架运动过程中的变化规律,并对原导向机构存在的问题进行了优化计算。结果表明,前轮定位参数在优化前、后的变化量较小,均在设计要求的范围内;轮距和前轮侧向滑移量的变化较大,优化后二者都在理想的范围内变动,达到了预期优化目标。     

轿车车身结构修改灵敏度分析

建立某国产普通轿车白车身的有限元模型,预测分析其静态弯曲特性和扭转特性,在此基础上对白车身各部件刚度和强度的灵敏度进行分析,并将分析结果应用于板厚优化。优化结果表明:通过对灵敏部件的板厚修改,白车身的强度和刚度性能得到显著提高,为车身的优化设计提供参考。     

基于RMA方法的汽车车身CAN总线优化设计

针对汽车车身控制信息的高实时性和车身CAN系统扩充的高灵活性等特殊要求,介绍用于实时系统分析的速率单调分析(RMA)方法,在原总线利用率、信息最坏响应时间等实时性指标基础上引入总线扩展灵活性因子进行车身CAN总线方案的寻优设计,并以典型汽车车身控制系统为例,对单信号方案和信号组合方案进行实时性和扩展灵活性对比分析,在线试验结果验证了理论分析数据的正确性。     

乘用车DCT车型的动力性提升分析与实施

为满足公司的发展战略要求,需要打造一款高性能、运动操控性车型,为提升该款乘用车DCT车型的动力性和操控型,分别从车辆的起步、加速过程的扭矩发挥和换挡结束的扭矩恢复、换挡过程的扭矩交替时间和转速同步时间、换挡线加速度和动力升挡换挡线及硬件五个方面进行优化。论文对该车型的起步加速过程以及换挡过程的扭矩控制进行详细分析,并将五个优化方向分解为13个子项,分别对各子项优化效果进行分析,通过INCA软件对车辆的控制系统进行优化,经过实际道路测试满足了目标开发要求。     

基于改进粒子群算法的机组经济运行的博弈

在电力市场下如果能够根据实时电价求出在该电价下机组经济运行状况,可以给发电公司权衡报价风险和企业利润提供极大的帮助.如果发电公司仅依据发电成本报价,在参与竞价上网时会因缺乏灵活性而造成机组被迫频繁停机和利润空间的浪费.为此,根据企业利润最大化原则建立机组经济运行数学模型,并用改进粒子群算法对模型优化求解.通过实例分析与传统方案的预测结果进行比较,说明其效果的优劣.其给发电公司决策提供更为灵活,有效的方法.     

Optimization of bus stop placement for routes on uneven topography

The improvement and expansion of public transport is an increasingly important solution to the high congestion costs and worsening environmental impacts of the car dominated transport systems seen in many cities today. The intelligent design of stop locations is one way to improve the quality of PT and thereby improve its ridership. Stop placement is a relatively complex task as it involves a trade-off between two competing goals; accessibility and operation; however this trade-off can be made explicit using an appropriate mathematical model. Many such models have been developed in the literature, however none consider the effects of uneven topography. Topography is an important but often neglected factor in the design of public transportation systems, with the potential to have a significant impact on the accessibility, operation and planning of a transit service. In this work a mathematical modelling approach to bus stop placement is developed which includes considerations of uneven topography in three ways; (1) Its effect on walking speed; (2) Its impact on the attractiveness of an access path to a transit service; and (3) Its effect on acceleration rates at stops. Because of the complexity of the model developed, a heuristic evolutionary algorithm’ is employed to approximate an optimal solution to the model. Finally, the model and solution method are applied to a case study in the Auckland CBD area in New Zealand.     

Ship service life extension considering ship condition and remaining design life

Reliable and continuous operation of ships is vitally important to the decision-makers. Driven by the rising cost of newbuilding ships, maintenance actions are needed on existing ships to ensure safe and enduring service beyond their initial design life. Extending ship service life can provide economic operating profit and promote sustainability. Meanwhile, ships during their extended service life may involve higher failure risk and additional maintenance expenditure. Therefore, a cost-benefit evaluation is imperative for determining the optimal duration of service life extension (SLE) and the associated maintenance actions. In this paper, a novel method for this purpose is proposed. Two cost-benefit indicators, benefit-cost ratio (BCR) and net present value (NPV) are used to optimize the duration of SLE. Using Bayesian updating, information on the remaining design life and the structural condition at the SLE decision is incorporated into the optimization process to better inform SLE decision-making. The proposed method is illustrated by a fatigue-sensitive very large crude carrier (VLCC) at both structural component and structural system levels.     

发动机凸轮轴后端盖密封失效分析及优化

针对某型发动机开发试验中出现的凸轮轴后端盖密封失效问题，应用非线性有限元软件ABAQUS对后端盖、密封垫以及缸盖组成的整体系统进行了数值模拟，得到厂后端盖的变形和密封垫的压力分布。试验结果表明。导致密封失效的主要原因是后端盖刚度设计过低．对后端盖进行了结构优化，并进行了仿真和试验验证。结果表明，经优化后的凸轮轴后端盖能满足密封要求。