Prediction of fatigue life and estimation of its reliability on the parts of an air suspension system

Air suspension systems have been implemented in various commercial vehicles, such as buses and special purpose trucks, because of the comfortable ride and easy height control. An evaluation of the durability of vehicle parts has been required for service life and safety starting in the early stages of design. The cyclic load applied to the vehicle can cause fatigue failure of parts, such as the suspension frame. This paper presents a method to predict the fatigue life of the suspension frame at the design stage of the air suspension system used in a heavy-duty vehicle. To estimate the fatigue life using the SN method, the Dynamic Stress Time History (DSTH) is necessary for the part of interest. DSTH can be obtained from the results of the flexible body dynamic analysis using the Belgian road simulation and the Modal Stress Recovery (MSR) method. Furthermore, the reliability of the predicted fatigue life can be evaluated by considering the variations in material properties. The probability and distribution of the expected life cycle can be obtained using experimental design with a minimum number of simulations. The advantage of using statistical methods to evaluate the life cycle is the ability to predict replacement time and the probability of failure of mass-produced parts. This paper proposes a rapid and simple method that can be effectively applied to the design of vehicle parts.     

Modeling NOx and NO2 emissions from mobile sources: A case study for Hamilton, Ontario, Canada

This study characterizes the dispersion of emissions of oxides of nitrogen and nitrogen dioxide from traffic sources in the Hamilton census metropolitan area. The Integrated Model of Urban Landuse and Transportation for Environmental Analysis software was used to estimate emissions of oxides of nitrogen from traffic sources. The Air Pollution Model, was used to simulate dispersion of the traffic emissions over the city. The models account for the two primary wind directions in this region – the prevailing southwest and a secondary northeast direction. The results show a prominent triangle of high pollution defined by major roads and highways along the periphery of the Hamilton Harbour, at peak-hour. With southwest winds, residential areas along the northern shoreline of the Harbour are affected, while the western sections of the city are affected by northeast winds. High concentrations are persistent in some areas, for both wind directions. The resulting dispersion surfaces characterize the spatial distribution of traffic emissions and thus provide a means of assessing population exposure over the Hamilton area.     

关于散装化学品船安全运输的几点思考

本文分析了散装化学品的危险性和散装化学品船的特殊危险性,系统分析了散装化学品船安全管理中存在的主要问题,提出和总结了加强散装化学品船安全运输的几项措施。     

高箱对船舶稳性影响的定量分析

对集装箱船舶装载高箱后稳性受到的影响进行了量化分析。并求出计算方法和计算公式。通过量化计算，掌握高箱对稳性的影响程度，从而确定相应对策。防止其影响安全。     

H轮副机配气机构的改进尝试

此文通过对H轮副机机损的故障分析,阐述了由于气阀机构的磨损而发生故障的机理,并提出了改进措施。     

2500吨级半舱甲板货船中剖面设计

本文通过对2500吨级半舱甲板货船四种中剖面结构形式的总纵强度进行计算比较分析，得出较优的中剖面形式是：采用下甲板与内舷板相连接在下甲板平面，内舷板下设甲板纵桁及支柱，其中剖面截面积较其他形式减少2．7％-3．6％，重量可降低，是值得进一步研究的半舱甲板货船船型结构方式，可供设计参考。     

货物单元系固方案校核方法的运用

在船舶运输中,货物单元合理系固是确保船舶安全的重要因素。IMO关于货物单元系固所提供的经验方法和精确计算方法,在实际应用中各有优点和不足,针对这两种方法的效果进行比较研究,在确保船舶安全的前提下,找到一种既精确又更为便捷的方法,具有普遍适用性。     

独立液货舱型式沥青运输船设计特点

阐述了独立液货舱型式沥青运输船在设计方面较常规船舶的特殊之处,主要表现在总体布置、结构布置、独立舱支承装置、独立舱定位装置、防浮装置、独立液货舱绝缘、结构防火与消防以及永久性检验通道等方面。     

气压制动系统储能装置容量特性研究

建立了气压制动系统的简化模型，研究了和储能装置容量特性相关的制动器促动刚度、气室推力和容积以及制动过程中气体的热力学特性，介绍了计算储能装置容量特性的方法。最后讨论了储能装置容量的法规适应性检验、制动系统设计参数协调性、制动问隙对制动力影响和变型车制动系统设计等问题。     

液货舱自由液面修正

探讨了国际海事组织(IMO)完整稳性规则自由液面修正条款对满载液货舱的适用性,提出了液货舱自由液面修正建议。