灵敏度分析在铸件优化设计中的应用

在铸件设计时一般都是先经过拓扑优化然后再进行结构设计,但拓扑优化无法得到确定结构的最优尺寸,仅能得到给定边界条件下的基本形式,因此在拓扑优化后如何进行详细尺寸设计对设计者要求较高,有时会设计出很多方案进行强度验证,且这些方案往往不是最优方案。在拓扑优化分析完毕后再加入灵敏度优化技术,可以快速得到满足设计要求且重量最轻结构的详细尺寸,大大提高了设计效率。     

岩土工程的可靠度研究

分析了常规定值设计法的不足,指出了可靠度方法在工程结构设计中的科学性、合理性和经济性;简单论述了可靠度的计算方法,对岩土工程的特点和不确定性的来源进行了分析;最后简要介绍了可靠度分析方法在岩土工程中的应用前景.     

浅谈LKJ设备运用异常的分析与判断

列车运行监控记录装置(LKJ)是重要的行车监控设备,列车运行的距离误差和机车信号的错误动作是造成LKJ系统误动的重要原因。及时对设备动作进行分析,掌握设备运用特点,方能及时有效地采取措施,确保运输生产安全。为此从设备异常动作的信息特征入手,着重剖析和查找机车信号的异常问题,解决设备生产运用中存在设备缺点。     

SG型轨道式水泥混凝土摊铺机组的主要机构设计

简单介绍了SG型轨道式水泥混凝土摊铺机组中布料机、振实机的升降机构设计构思,对该机构在静止、起升、下降状态进行了受力分析与计算,并详尽地给出了其计算程序,进一步对运算结果进行具体分析。     

滚子轴承状态监测技术中基本振动的评价

通过已受损伤滚子轴承产生振动的方法,阐述如何测量这种振动和怎祥将这种振动从机器其它零件所产生的振动中分离出来,如何分析和评价这种振动以及怎样检验各种缺损的部位和轴承的工作状态,由此来预测轴承的剩余寿命。     

自重荷载作用下悬索静力解析解

从悬索微元体平衡出发,分别推导以悬索张力分量、索长等为参变量,考虑和不考虑悬索自重集度变化的两种悬索解析式。通过比较发现,去掉悬索伸长影响项,就可直接由考虑悬索自重集度变化的解析式缩减到不考虑其变化的解析式。在用索长表达的解析式中,考虑悬索自重集度变化时对应无应力索长,不考虑悬索自重集度变化时对应有应力索长。算例假定斜拉索梁端张力的竖向分量为已知,按以上两种情况,分别建立以悬索张力的水平分量和塔端张力的竖向分量为未知数的非线性方程组,用拟牛顿法求解,得到悬索未知参数的精确解析解。     

中国轿车如何走好自主之路(续1)

1中国轿车自主品牌问题的提出轿车工业的发展水平是汽车工业发展水平的主要标志。我国汽车工业经过52年的发展,取得了长足的进步,2005年中国汽车产量已达到570.77万辆,轿车产量已达到393.07万辆。轿车已经成为汽车产业的排头兵,表1列出近10年中国汽车及轿车产销量情况。由表1可     

红水河十五滩航道整治设计

十五滩是西南水运出海中线通道(红水河广西段)中的著名滩险,集急、浅、险、弯于一体,整治难度较大。文章利用实测水文观测资料进行水流条件及碍航特性分析,在此基础上,结合工程实际提出该滩的整治原则,并利用物理模型试验的成果进行航道整治工程设计,设计技术标准不只局限于航道等级对航道尺度的要求,还根据降低流速和减缓比降的需要,将滩口或相应部位作加宽、加深处理,以便改善流态,满足航行要求。工程实施后,扩大了航道尺度,解决了“险”、“窄”、“弯”等问题。     

多品种产品的线性盈亏分析

结合实例,对多品种产品生产销售的几种线性的盈亏平衡分析法及其运用条件进行了探讨和分析,以找到一种有效的分析方法,以提高企业的经济效益.     

Towards a more equitable distribution of resources: Using activity-based models and subjective well-being measures in transport project evaluation

In this paper, we develop an innovative and comprehensive transport evaluation criterion to better account for equity considerations in transport project evaluation. This work explores transportation benefits from the consumer’s perspective to accessibility as a key benefit generated by any transportation project. To assess the full benefits of transportation project implementation for various consumers and calculate the improvement in accessibility, it is best to use Activity-Based Models (ABM). ABMs have two important advantages for equity analysis, which have not been utilized in the literature so far: first, ability to analyze results by various groups of the population; second, these models can utilize the Activity Based Accessibility (ABA) measure to estimate the overall benefits from transport investments and policies. The ABA measure allows one person to have different accessibilities for different choice situations, depending on his/her characteristics. We suggest including social and spatial factors in social welfare assessment by introducing the concept of accessibility gains to key social activities. Specifically, it is suggested to incorporate subjective well-being consideration into a new evaluation framework “Equity Benefit Analysis” (EBA). we use an alternative measure, “Subjective Value of Accessibility gains” (SVOA), which is based on the ABM accessibility measure as well as on Subjective Well-Being (SWB) measure, as the key benefit taken into account in the evaluation process. The SVOA is not intended to replace the current practice of analyzing equity by comparing various impacts on different groups of the population, but can aid by providing policymakers with a single measure advancing both equity and efficiency considerations and facilitating comparison among alternatives. Initial case study results indicate the SVOA can show higher benefits to policies focusing on the needs of vulnerable social groups that compared traditional measures.