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221.
W. H. Elmaraghy Faculty of Engineering Science 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1987,16(4):193-211
This paper describes mathematical and computer models for ride quality and dynamics of rail vehicles developed for running on personal computers. The purpose of the computer simulations is for prediction of ride quality in order to study the dynamic stability of the system and the effect of track quality and irregularities on ride quality.
In deriving the equations of motion for dynamic stability, the tangential forces acting on the contact areas between the wheels and rails are of fundamental importance in railway vehicles dynamics and are included in the analysis [1]. These forces are due to the creep phenomenon between the wheel and the rail on which it is rolling. Track irregularities are defined in terms of four components consisting of gauge, cross level, alignment and vertical surface profile [2]. Relation of allowable track irregularities versus speed is given by the FRA Track Safety Standards. Analytical representation of track irregularities should include both PSD (Power Spectral Density) for CWR (Continuous Welded Rail) as well as discrete inputs from track joints.
In this paper, the rail vehicle suspension analysis and dynamics mathematical and computer models are described. The computer models are written in Fortran 77 and designed to run on personal computer. The paper also discusses programming considerations that must be taken into account when programming for microcomputers under DOS (IBM's Disk Operating System) and MS or RM Fortran Compilers. Most of the considerations are however, valid in general with respect to engineering software development and programming for microcomputers.
Computer graphics is a powerful tool for visualization of the resulting solutions such as the display of the characteristic roots for the eigenvalues solution on a root locus plot and representation of acceleration levels versus the “Reduced Comfort Boundary” limits defined by the International Standards Organization” (ISO 2631-1985). In this paper some examples of these resulting outputs are presented and their significance discussed. 相似文献
In deriving the equations of motion for dynamic stability, the tangential forces acting on the contact areas between the wheels and rails are of fundamental importance in railway vehicles dynamics and are included in the analysis [1]. These forces are due to the creep phenomenon between the wheel and the rail on which it is rolling. Track irregularities are defined in terms of four components consisting of gauge, cross level, alignment and vertical surface profile [2]. Relation of allowable track irregularities versus speed is given by the FRA Track Safety Standards. Analytical representation of track irregularities should include both PSD (Power Spectral Density) for CWR (Continuous Welded Rail) as well as discrete inputs from track joints.
In this paper, the rail vehicle suspension analysis and dynamics mathematical and computer models are described. The computer models are written in Fortran 77 and designed to run on personal computer. The paper also discusses programming considerations that must be taken into account when programming for microcomputers under DOS (IBM's Disk Operating System) and MS or RM Fortran Compilers. Most of the considerations are however, valid in general with respect to engineering software development and programming for microcomputers.
Computer graphics is a powerful tool for visualization of the resulting solutions such as the display of the characteristic roots for the eigenvalues solution on a root locus plot and representation of acceleration levels versus the “Reduced Comfort Boundary” limits defined by the International Standards Organization” (ISO 2631-1985). In this paper some examples of these resulting outputs are presented and their significance discussed. 相似文献
222.
通过焊接和拉伸试验及微观组织分析,研究了焊接参数对高强度301L-HT板搭接非熔透激光焊接接头结构、断裂行为和力学性能的影响.结果表明:激光焊缝的硬度为HV215,δ铁素体比电阻点焊少,热影响区硬度更接近于母材;焊缝几何结构对激光参数敏感,熔深变化的规律性更明显,特定部位的熔宽与焊接参数耦合有关;板材厚度相同的焊接接头变形刚度接近,焊缝的几何结构决定最后的变形和断裂行为,焊接内板的弯曲变形角度比外板大,两板的弯曲角度差随熔深增加而减小;焊接板弯曲角度和焊接强度随焊缝尺寸同步升高;焊缝硬度低于母材和热影响区导致拉伸变形集中在很窄的区域,焊接接头的断裂位移都小于2mm. 相似文献
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226.
Generalization of Results of Computations and Natural Experiments at Steel Parts Quenching 总被引:1,自引:0,他引:1
Nikolai I.Kobasko Engineering Thermophysics Institute of National Academy of Sciences Kyiv Ukraine 《上海交通大学学报(英文版)》2000,(1)
IntroductionThepaPerpresentsthegenera1izationofresultsofnumericalcomputationsandnaturalexperimentsbasedonthesimilaritytheoryandtheoryofregularthermalconditions.Thenumericalcomputationshasbeenmadeonthebasisofsolvingequationsofnon-stationarythermalconductivityandthermoplaSticity.Thegeneralizationofresultsliesinthefactthatwefoundadimensionlessformulaforthedeterminationofthetimeofreachingthemaximumcompressionstressesonthesurfaceofp8rtstobequenched.ThepatstobequenchedaredividedintothreegrouPs:pla… 相似文献
227.
采用基于机器视觉的三角测距原理和光取断面法,开发出将廓形上的激光点进行空间坐标转换的算法,消除了已有方法中借助标定板计算所带来的误差和操作的复杂性,提高了钢轨动态测量的精度和效率.开发了非接触式钢轨检测装置.通过对60轨打磨后轨廓的测量结果与标准廓形的分析比对,验证了开发系统的精度和性能. 相似文献
228.
Winkler弹性地基上预应力锚索地梁内力的计算方法 总被引:12,自引:0,他引:12
介绍用Winkler弹性地基梁计算预应力锚索地梁的内力 ,并给出主要计算流程。结合京珠高速公路某工点工程实例 ,将Winkler弹性地基梁和连续梁方法的计算结果与工程实测进行比较 ,指出在预应力锚索地梁正常工作状态下 ,采用Winkler弹性地基梁方法所得结果与真实情况更为吻合 相似文献
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ZHANG Xiao-fei LU Huang WU You-ren The Second Engineering Company of CCCC Fourth Harbor Engineering Co. Ltd. Guangzhou CCCC Sihang Engineering Institute Co. Ltd. Guangzhou 《华南港工》2007,(4)
标准贯入试验作为岩土工程中一种原位测试方法,可以应用于砂桩桩体质量检测,并能较全面地反映砂桩的施工质量和评价复合地基加固效果。本文结合工程实例,对采用标准贯入试验方法用于砂桩桩体质量检测进行探讨分析,总结了试验过程中的注意事项,提出了桩体试验点位置的试验后处理方法,讨论了实测数据修正和成果运用问题,并归纳了砂桩施工时可能存在的问题,为相关工程技术人员提供参考。 相似文献