载重汽车变速箱效率测试台的研制浅析

本文介绍了载重汽车变速箱效率测试台的试验条件及设计方法,以实际例子进行了台架仪器仪表及元件选型的综合分析。     

ZPW-2000A型闭环电码化系统

介绍了ZPW-2000A型闭环电码化系统的设备构成及正线和侧线闭环电码化检测的工作原理。     

汽车制动鼓静平衡微机测试仪的研制

根据力学静平衡原理，采用传感器技术、微机接口技术、计算技术和机电一体化设计，研制成功了汽车制动鼓静平衡测试仪。该测试仪使用灵活、测试精度高。介绍了该测试仪的测试原理、仪器结构和软件流程，并对测量误差进行了分析。     

作业场所粉尘危害程度不同方法的研究比较

采用密切值、秩和比，同时依据ＧＢ５８１７－８６分级标准对作业场所粉尘的危害程度进行了研究比较。结果表明：３种方法的Ｒｉｄｉｔ值分别为０．５２４５、０．４７５４、０．４９９９，经χ＾２检验３中方法之间差别无统计学意义（χ＾２＝０．３２８７）＇Ｐ＞０．０５）。     

铁路改建设计中充分利用既有园曲线的几种方法

介绍了铁路既有圆曲线在改建中如何更好地利用以减少废弃的几种设计和测量方法     

An optical tire contact pressure test bench

An optical tire contact pressure test bench developed by the IMMa group is described. The measurement system is based on the frustration of total internal reflection (FTIR) of light. The test bench allows performing normal pressure distribution and patch contact shape measurements on passenger car tires. The system is based on the use of a laterally illuminated glass on which the tire leans. Between them a plastic interphase is located that will cause the FTIR of light. A video camera catches the formed shining image through the glass. The brightness level in each pixel of the image can be related to the existing normal pressure. The study of the contact patch provided by the bench makes it possible to characterize tire behaviour under different loading states, inflation pressure, tire defects and toe and camber angles. The bench incorporates a computerized load and control system of the tire operation parameters, an image acquisition module and a data acquisition system that allow monitoring and acting on the experimental variables of interest in the tests such as load on the tire and environmental conditions. A supporting mechanical system incorporated to the bench allows providing the tire with variable toe and camber angles. From the images obtained with this system, the maximum normal pressure points, total force, size and shape of the patch can be determined, which are related to the tire-use conditions. As an application example, results that show the patch size and shape under different load and tire inflation pressures are presented. A further application, which is the use of the system for the detection and study of defective tires is also presented.     

青藏铁路GSM-R无线网络场强覆盖测试探讨

从工程角度探讨青藏铁路GSM-R网络场强覆盖测试的重要性和必要性，着重从数据采集方法、采样间隔与同时采集的频点数之间的关系，以及数据处理方法等方面进行了阐述。     

T7型检衡车使用、维护及检定情况概述

目前在铁路上广泛使用的有T6D,T6F,T7等型号的检衡车,而T7型检衡车在静态轨道衡计量检定工作中得到广泛应用,本文从影响检衡车标称值的角度浅谈其复现性和使用维护应该注意的事项。     

深圳地铁大轴力桩基托换模型试验研究

通过1∶4模型试验研究,分析凿毛、企口、锚筋和预应力等接头处理方式的梁—柱接头的抗剪性能,提出采用"企口 锚筋 预应力"的接头型式作为大轴力桩基托换的梁—柱接头连接方式。并用1/2模型试验验证该种接头的安全性和可靠性。通过1/4整体模型试验,研究了大轴力桩基主动托换过程中托换荷载在托换结构中的分配关系及截桩过程中荷载的转换规律。     

高速铁路接触网动力学响应实验及仿真

对接触网在受电弓/接触网垂向耦合振动过程中的瞬态位移和应力响应进行研究。对某试验接触网进行了动应力测试实验,并与有限元计算结果进行比较,误差在10%以内。利用有限元软件ANSYS建立Re250 0型简单链型悬挂接触网的二维模型,采用模态叠加法进行瞬态仿真分析,得到接触网的位移及应力时间历程。结果说明随着车速提高,接触网振动加剧,动态位移和应力显著增加,对接触网的疲劳和安全可靠性会造成严重影响。