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首页> 外文学位 >VIBRATIONS OF RAILROAD TRACKS SUBJECT TO OSCILLATING AND MOVING LOADS (NATURAL FREQUENCIES, CRITICAL VELOCITY, ELASTIC LAYER, HALFSPACE).
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VIBRATIONS OF RAILROAD TRACKS SUBJECT TO OSCILLATING AND MOVING LOADS (NATURAL FREQUENCIES, CRITICAL VELOCITY, ELASTIC LAYER, HALFSPACE).

机译：轨道振动随载荷和运动载荷（自然频率，临界速度，弹性层，半空间）的变化而变化。

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摘要

The resonant frequency of the railroad track was first determined by Timoshenko 6 , by modeling the track as a beam on a massless Winkler foundation. The mass of the foundation and of the vibrating load was not included in the formulation. He provided a simple expression for the resonant frequency (omega)(,R) = SQRT.(k/m, where k is the Winkler constant and m is the mass per unit length of the beam. He also stated, "The track moves like a rigid body at resonance".; First the effect of the unsprung mass of the vibrating load on the dynamic response of a railroad track, is determined. To simplify the analysis the track is modeled as a beam on the Winkler foundation. A dynamic analysis, without assuming a priori, a steady state solution, is carried out in order to establish the effect of this assumption. This procedure demonstrates the significant effect, of even a small amount of load mass, on the dynamic response of the beam resting on the Winkler foundation. The question, regarding Timoshenko's statement that the track moves like a rigid body at resonance, is also clarified.; As a prelude to the study of the effect of the mass of the foundation on the natural frequencies of the railroad track, the simpler plane strain problem of a beam resting on a 2-dimensional inertial elastic layer is solved first. Then, the natural frequencies of the railroad track are determined. The track is modeled as a beam resting on a 3-dimensional inertial elastic layer. The frequency equation is found, in order to determine the natural frequencies. It is shown that the mass of the foundation has a significant effect on the natural frequencies of the railroad track.; Since the response of the track on a 3-D layer subjected to an oscillating load with mass is difficult to evaluate in closed form, a simple 3-dimensional inertial foundation model, which consists of a 3-D shear layer resting on closely spaced inertial rods, is introduced. It is shown that the frequency equation for determining the natural frequencies of the beam resting on this foundation is the same as derived earlier for the beam resting on a 3-D inertial layer.; Lastly, the response of the concrete slab track to moving loads is analyzed. The track model used consists of rails on a long slab resting on a 3-dimensional inertial elastic half-space. Using Filippov's approach this moving load problem is then analyzed for the dynamic response.
机译：铁轨的共振频率首先由Timoshenko 6确定，方法是将轨道建模为无质量Winkler基础上的光束。配方中不包括基础质量和振动载荷。他提供了谐振频率（ω）（，R）= SQRT。（k / m的简单表达式，其中k是Winkler常数，m是光束每单位长度的质量。他还说，“轨道移动就像刚体在共振时一样。”；首先确定振动载荷未悬挂的质量对铁轨动力响应的影响。为了简化分析，将轨道建模为Winkler基础上的梁。为了确定该假设的效果，在没有先验先验的情况下进行了稳态分析，该程序证明了即使是很小的负载质量，也对固定梁的动态响应产生了显着影响。温克勒基金会。关于提莫申科关于轨道在共振时像刚体一样运动的陈述也得到了澄清；作为研究基础质量对铁轨固有频率影响的序言，平面应变首先解决束在二维惯性弹性层上的障碍。然后，确定铁轨的固有频率。轨道被建模为位于3维惯性弹性层上的梁。找到频率方程，以便确定固有频率。结果表明，地基的质量对铁轨的固有频率有重大影响。由于在封闭形式下难以评估承受质量振动载荷的3D层上轨道的响应，因此需要一个简单的3维惯性基础模型，该模型由一个3D剪力层紧靠间隔的惯性组成棒，介绍。结果表明，用于确定置于该基础上的梁的固有频率的频率方程与先前针对置于3-D惯性层上的梁的频率方程相同。最后，分析了混凝土平板轨道对移动荷载的响应。所使用的轨道模型由位于3维惯性弹性半空间上的长平板上的轨道组成。然后，使用Filippov的方法分析此移动负载问题的动态响应。

著录项

  • 作者

    PATIL, SHIRISH PADMAKAR.;

  • 作者单位

    University of Delaware.;

  • 授予单位 University of Delaware.;
  • 学科 Applied Mechanics.
  • 学位 Ph.D.
  • 年度 1984
  • 页码 173 p.
  • 总页数 173
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 应用力学;
  • 关键词

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