利用AM解析法实现不规则波的入反射分离

基于分离规则合成波的解析方法,提出了不规则合成波分离的理论技术,将不规则波浪等价为特定频率规则波进行分离,首先通过数值模拟方法检验,分离叠加30%噪声的模拟合成波浪,分离精度利用相关系数评价达0.97,然后测试无反射造波水槽中的现场合成波浪,经波谱分析,分离精度能够达到工程标准。     

基于HyperWorks的车身地板的有限元分析

以某车型的车身地板模型为例,利用有限元分析软件HyperWorks中的HyperMesh模块对车身地板进行网格划分,运用Optistruct模块对其进行模态分析,分析其固有频率及振型。目的是为了使汽车的结构在设计中尽量避免共振和噪声,加强其稳定性和安全性,也为实际生产提供了参考和依据。     

基于模糊AHP法的炮兵指挥信息系统效能评估

从现代战争对炮兵指挥信息系统的需求出发,建立了炮兵指挥信息系统效能评估指标体系,运用模糊层次分析法对系统效能进行评估,并通过实例说明评估的可行性,为炮兵部队指挥信息系统评估提供了一种方法和途径。     

我国二手车市场经营管理模式的探讨

针对二手车市场的特点,结合目前我国二手车流通领域中存在的主要问题,提出了规范我国二手车市场经营管理的具体建议。     

现代轿车车架结构现状与技术发展

1轿车车架的发展概况汽车诞生至今已有一个多世纪,轿车车架结构己经变迁。从最早的类似马车结构的装甲木质车架开始,轿车车架发展历史上曾出现过梯形车架、带X型横梁的梯形车架、脊骨式车架、X型车架、和周边式车架等。从有车架的非承载式车身结构到没有车架的承载式车身结构。     

考虑初始缺陷的结构非线性屈曲分析与应用

在船舶结构领域,考虑初始缺陷的非线性结构分析已越来越受到重视,并逐渐引向工程实际应用。在国际船级社协会的共同结构规范(IACS-CSR)和国际海事组织的目标型标准(IMO-GBS)的有关技术文件中,均明确规定了非线性屈曲失效模式中应考虑初始缺陷因素。作者以著名的高级非线性分析软件MSC/Marc为计算分析手段,对初始缺陷结构非线性屈曲分析方法中主要因素影响的敏感性进行了研究,其中涉及深入的探索工作,并提出该类分析工作的规范性准则。     

Timing rules for major transportation investments

The timing decision for major transportation investments – when to build – typically is made without an objective approach for considering the economic value of implementation at different times. This paper uses a model of benefit-cost analysis and derives rules for timing major transportation investments. Three sets of conditions are considered, depending on whether annual benefits of an investment are uncertain and whether the objective is to maximize net present value or simply to achieve positive net present value. The timing rules under each set of conditions are stated in three forms: benefit-cost ratio, annual benefits, and implementation time. The paper compares these timing rules analytically, discusses potential applications, and illustrates them with a numerical example. Consequences of incorrectly using the timing rules are also examined with the example. This revised version was published online in June 2006 with corrections to the Cover Date.     

教育部基金管理信息系统的设计与开发

作者介绍了教育部基金管理信息系统的研究与设计方法,阐述了系统的功能和特点,探讨了数据兼容,对时间的处理以及报表打印的关键技术问题.并针对该系统最关键的评审部分提出了进一步的设想,既用基于WEB的知识挖掘的思想,知识挖掘与网络技术相结合来选择各学科领域的专家建立评审专家库     

Dynamic Interaction of Railway Train and Bridges

An analytical method for obtaining the dymanic responses of a train of locomotives moving on bridges is presented. The ratio of dynamic response to maximum static response is called the amplification factor, and its maximum absolute value minus one is called the impact. Each four-axle locomotive is modelled as a rigid body with three degrees of freedom: bounce, pitch and roll, and with a suspension system consisting of springs mounted on wheels. The locomotives are assumed to be connected by frictionless joints to form the train. The bridge is modelled as a three dimensional structure, with the masses lumped at the truss joints. All joints, including the floor beam connections, are assumed to be rigid, except those for the bracing members, which are assumed to be hinged. Vertical displacements are considered as the only dynamic degree of freedom. The mathematical formulation is described briefly, and a numerical example is given. Locomotive and truss member properties, together with stresses in some typical members, are given in the tables. The amplification factors of the responses in some typical bridge members are shown in the figures.     

洪泽湖蒋坝水位站迁址重建的分析与设计

蒋坝水位站是洪泽湖代表水位之一,是淮河流域防汛抗旱调度的重要依据。建于1914年1月,2004年4月迁址重建。分析了蒋坝水位站的代表性;介绍了站址方案的选择和水位观测平台高程的确定。叙述了水位观测平台的结构型式和结构设计,以及施工情况。通过一年的比测,新建的蒋坝水位站达到了设计目的,在2007年淮河大水中发挥了重要作用。