铁路平车车体造修典型故障原因分析及其改进措施

分析了铁路平车车体在制造和检修中典型故障的形成原因,并提出了改进措施.     

出口泰国米轨集装箱平车的研制

介绍了出口泰国米轨集装箱平车的主要技术参数、车辆结构和试验情况。     

液压组合挂车转向机构换位孔的可制造化处理

根据任意轴线下液压模块式组合挂车转向系统的优化设计原理,通过合并法、分开法、综合法三种孔位处理方法,实现了对优化后的换位孔的可制造化处理,取得了满意的效果。     

The effect of railway local irregularities on ground vibration

The environmental effects of ground-borne vibrations generated due to localised railway defects is a growing concern in urban areas. Frequency domain modelling approaches are well suited for predicting vibration levels on standard railway lines due to track periodicity. However, when considering individual, non-periodic, localised defects (e.g. a rail joint), frequency domain modelling becomes challenging. Therefore in this study, a previously validated, time domain, three-dimensional ground vibration prediction model is modified to analyse such defects. A range of different local (discontinuous) rail and wheel irregularity are mathematically modelled, including: rail joints, switches, crossings and wheel flats. Each is investigated using a sensitivity analysis, where defect size and vehicle speed is varied. To quantify the effect on railroad ground-borne vibration levels, a variety of exposure–response relationships are analysed, including: peak particle velocity, maximum weighted time-averaged velocity and weighted decibel velocity. It is shown that local irregularities cause a significant increase in vibration in comparison to a smooth track, and that the vibrations can propagate to greater distances from the line. Furthermore, the results show that step-down joints generate the highest levels of vibration, whereas wheel flats generate much lower levels. It is also found that defect size influences vibration levels, and larger defects cause greater vibration. Lastly, it is shown that for different defect types, train speed effects are complex, and may cause either an increase or decrease in vibration levels.     

A dynamic wheel–rail impact analysis of railway track under wheel flat by finite element analysis

Wheel–rail interaction is one of the most important research topics in railway engineering. It involves track impact response, track vibration and track safety. Track structure failures caused by wheel–rail impact forces can lead to significant economic loss for track owners through damage to rails and to the sleepers beneath. Wheel–rail impact forces occur because of imperfections in the wheels or rails such as wheel flats, irregular wheel profiles, rail corrugations and differences in the heights of rails connected at a welded joint. A wheel flat can cause a large dynamic impact force as well as a forced vibration with a high frequency, which can cause damage to the track structure. In the present work, a three-dimensional finite element (FE) model for the impact analysis induced by the wheel flat is developed by the use of the FE analysis (FEA) software package ANSYS and validated by another validated simulation. The effect of wheel flats on impact forces is thoroughly investigated. It is found that the presence of a wheel flat will significantly increase the dynamic impact force on both rail and sleeper. The impact force will monotonically increase with the size of wheel flats. The relationships between the impact force and the wheel flat size are explored from this FEA and they are important for track engineers to improve their understanding of the design and maintenance of the track system.     

预弯梁的设计与施工研究

本文结合对哈尔滨市先锋路、红旗路立交桥大跨径预弯梁的设计、施工监测及试验数据监控分析 ,就预弯梁在国内外的发展状况、结构的尺寸特点、优势、适用范围及其实用效果、工程设计体验、施工方式、计算手段等进行探讨和交流。     

袋装砂井处理河滩相软土固结沉降研究

以河滩相软土为研究对象,利用沉降板、测斜管、孔隙水压计等测试仪器,选取有代表性的观测断面,进行了一年多的沉降与稳定观测。通过对观测数据进行整理与分析,推算出符合工程实际的最终沉降量、固结沉降量及地基平均固结度,进而从三个方面对袋装砂井加速河滩相软土固结效果进行了评价。同时提出了固结度参数β的参考值,对在河南省河滩相软土地基上修筑高等级公路具有重要的参考价值。     

汽车电线电缆的发展动向

结合我国汽车电线电缆发展实际,阐述了当前汽车电线电缆产品的状况、要求和特点;对国内外汽车电线电缆的标准化状况和趋势进行了阐述;对国际上汽车电线电缆的相关发展动向进行了介绍和分析。     

城市桥梁预制装配化绿色建造技术应用与发展

城市桥梁建设中,为避免传统施工方法产生的弊端,采用标准化设计、工厂化生产、装配化施工的桥梁施工技术能有效缩短施工工期,提高施工质量,减少对城市环境污染.预制装配化施工技术基于"创新、协调、绿色、开放、共享"的发展理念,具有"一优二减三节四降"的优势.装配化绿色施工的基础是设计标准化,预制装配式桥梁上部结构需合理设置接缝...     

车轮扁疤冲击分析

扁疤车轮给轨道以极大的冲击作用,致使钢轨及混凝土轨枕受到料想不 到的伤损。本文按动量原理导出了车轮扁疤对轨道的冲击算式,分析了 扁疤车抢甘轨道的影响,提出了防止对策。