...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the institution of mechanical engineers >Further investigation of wheel climb initiation: Three-point contact
【24h】

Further investigation of wheel climb initiation: Three-point contact

机译：车轮爬升启动的进一步研究：三点接触

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In previous research, a set of nonlinear algebraic kinematic constraint equations were developed that describe the configuration of a wheelset in contact with a track at two distinct points. In such a case of two points of contact, a simplified wheelset model that has the lateral displacement and angle of attack as the independent variables can be developed. In the current investigation, this approach is extended to the new case of a wheelset in contact with a tangent track at three distinct points. The solution of this three-point contact problem requires specifying the wheelset angle of attack only. This wheelset configuration is significant in derailment investigations because it is a possible configuration at the initiation of a wheel climb derailment. In order to study this wheel climb initiation configuration, a set of nonlinear kinematic constraint equations is developed as a function of the wheelset angle of attack and solved for the unknown system coordinates and contact surface parameters using an iterative Newton-Raphson algorithm. The wheelset angle of attack during wheel climb derailments can be determined forensically at the derailment site, making this approach of practical significance. It is shown in this investigation that the system configuration can be fully defined for wheel climb derailment initiation, which allows for the investigation of various derailment parameters such as the wheel-rail contact angle. It is then reinforced in this study that the wheelset flange angle, which is the angle between the tangent to the wheel surface at the contact point and the wheelset axle, is not representative of the wheel-rail contact angle, which is the angle between the tangent to the contact surfaces and the lateral common tangent to the two railheads; this distinction can only be demonstrated through full definition of the system configuration that accounts for the wheelset roll angle. This investigation therefore calls into question the Nadal L/V derailment limit as well as any investigation that chooses to neglect the wheelset orientation or the effect of such orientation on the wheel/rail contact geometry. This new formulation is validated and supported using a three-dimensional fully nonlinear unconstrained multibody system wheel climb derailment model recently proposed in a previous study. Using this model, new results demonstrate that initiation of the wheel climb motion is correctly predicted using proper geometry definitions in the derailment criteria, whereas previous results demonstrated such motion was not correctly predicted using the geometry definitions used by Nadal. This investigation is not intended as a derailment criteria proposal, but rather as support and rationalization for the use of correct contact geometry in derailment investigations. This investigation reiterates the important result that the Nadal L/V derailment limit is not conservative, and demonstrates that, with proper formulation, more accurate and justifiable derailment criteria can be developed.
机译：在先前的研究中，开发了一组非线性代数运动学约束方程，该方程描述了轮对在两个不同点处与轨道接触的配置。在两个接触点的情况下，可以开发简化的轮对模型，该模型具有侧向位移和攻角作为自变量。在当前的研究中，此方法扩展到轮对在三个不同点与切线轨迹接触的新情况。要解决这个三点接触问题，只需指定轮对的迎角即可。该轮对配置在脱轨研究中很重要，因为它是车轮爬坡脱轨启动时的一种可能配置。为了研究这种车轮爬升的初始配置，根据车轮对的迎角开发了一组非线性运动约束方程，并使用迭代牛顿-拉夫森算法求解了未知的系统坐标和接触面参数。车轮爬升脱轨期间的轮对迎角可以在脱轨现场进行法医确定，这使这种方法具有实际意义。在此调查中表明，可以完全定义用于车轮爬坡脱轨的系统配置，这允许调查各种脱轨参数，例如轮轨接触角。然后在这项研究中得到了加强，即轮对法兰角（即接触点处的车轮表面切线与轮对轴之间的角度）不能代表轮轨接触角，即轮轨接触角。与接触面相切，两个轨头的横向公共切线；这种区别只能通过完全解释轮对侧倾角的系统配置来证明。因此，这项研究对纳达尔的L / V脱轨极限以及任何选择忽略轮对方向或这种方向对轮/轨接触几何形状的影响的研究提出了疑问。最近在先前研究中提出的三维完全非线性无约束多体系统车轮爬升脱轨模型对此新公式进行了验证和支持。使用该模型，新结果表明，在出轨标准中使用正确的几何定义可以正确预测车轮爬坡运动的开始，而先前的结果表明，使用纳达尔使用的几何定义不能正确预测这种运动。该调查并非旨在作为出轨标准建议，而是作为对出轨调查中使用正确接触几何形状的支持和合理化。这项调查重申了重要的结果，即纳达尔L / V脱轨极限不是保守的，并证明了通过适当的表述，可以制定出更准确和合理的脱轨标准。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号