Optimum design of tilting bogie frame in consideration of fatigue strength and weight

This paper addresses the use of finite-element (FE) analysis to calculate the fatigue strength of a bogie frame, for the development of tilting trains in Korea. A multi-body dynamic analysis was performed to extract the load condition by tilting on curves. Using the results of the multi-body dynamic analysis and the load scenario setout in the UIC standard, FE analysis was performed to obtain the stress distribution and to calculate the fatigue strength. An attempt was made to minimize the weight of the bogie frame using a back-propagation artificial neural network (ANN). The results of this study reveal that the stresses at some nodes are near the fatigue limit in the Goodman diagram and by using back-propagation ANN, the weight of the bogie frame could be reduced by 4.7%.     

营业线施工应增加有关概算费用的探讨

针对目前铁道部有关加强行车安全的文件与设计概算编制规定不协调的问题,笔者提出了自己的看法.     

Digital exchange of design models between marine equipment libraries using hybrid neutral formats

The selection of marine equipment is a time-consuming process for a ship outfitting designer. The inefficiency originates from the paper-based exchange of design information between shipyards and equipment manufacturers. We propose a method to exchange equipment models for electronic commerce. Shipyard practices were investigated to find out how the outfitting CAD library is being used. We also surveyed international standards for the exchange of digital equipment models, and analyzed the macroparametric methodology. We propose a hybrid method to represent the geometric information using STEP AP203 or the macroparametric method. The nongeometric information is defined according to the Parts Library (PLIB) standard. We implement a pilot system and test it with a ship design data set. The equipment model proposed can be used in the design process with heterogeneous shipbuilding CAD systems. The equipment model can improve the design and purchase process in shipyards.     

Seabed scene simulation and its realization in extending Vega

Realistic simulation of underwater scene is always difficult because of the special and complex vision effects in underwater space. Seabed is an important part of underwater environment. This paper describes the methods for seabed scene simulation based on OpenGL. It includes construction of fluetuant terrain based on the random sinusoidal algorithm, simulation of seabed flicker effect by means of circular texture mapping and generation of turbidity effect by using fog techniques. For the application based on the leading high level 3D development environment-Vega, underwater scene simulation is still a difficulty since there is no module for it. Based on the analysis of Vega software and the research on seabed scene simulation methods, a Vega extending module named “Underwater Space” was created through developing module class and extending lynx interface. The module class was designed through developing DLL written in C . The Lynx was extended through developing keyword configure file, GUI configure file and lynx plug-in DLL. The problem that Vega can‘t simulate underwater space, is elementarily resolved. The results show that this module is efficient, easy using, and the seabed scene images am vivid.     

爆破振动对宋家湾隧道施工的影响

为评价在生产常规作业阶段爆破施工方式对隧道结构的影响,对宋家湾隧道爆破振动进行监测,以获取主振频率,最终以频率和振动速度2个指标评估隧道爆破作业振动效应。本次爆破的最大振动速度为3.1cm/s,主振频率范围为27.34～70.31Hz,最大振动速度远小于国家标准。可知对隧道支护结构影响有限频率范围为27.34～70.31Hz,远高于隧道的自振频率（一般在3～9Hz范围内）,不会出现共振放大现象。     

不规则构件钢筋的自动翻样技术探索

针对异形屋面结构中经常采用的不规则形状折梁设计,施工过程中充分利用AutoCAD三维立体图的方式,完成不规则折梁钢筋的翻样,化解翻样难度,提高翻样效率,保证翻样精度,同时阐述了如何解决施工过程中遇到的安装问题。     

我国汽车召回制度的发展现状及思考

丰田"召回门"引起的风暴冲击着全球的汽车召回管理体系,我国的汽车召回制度也在此次风暴中暴露出一些问题。文中回顾了我国汽车召回制度的发展现状,从立法层面、标准层面和监管层面分析了我国汽车召回制度存在的问题,并提出相关建议。     

舰载相控阵雷达功能仿真建模与软件设计

根据舰载相控阵雷达的组成及工作原理,介绍一种舰载相控阵雷达功能仿真的方法.重点描述雷达回波信号功率模型、噪声和干扰功率模型、杂波功率模型、综合信噪比模型等数学仿真模型.通过对仿真软件功能需求分析,给出软件结构、软件设计流程等软件开发要点.