Session: 07-08-03: Multibody Dynamic Systems and Applications III

Paper Number: 143387

143387 - Effects of Shaping Wheel Profiles for Vehicle Dynamics in Tramway 

The design of wheel profiles is paramount in railway vehicle dynamics, profoundly impacting wear, fatigue, noise, and vibration. Tramway wheel shaping, specifically, is intricately linked to derailment risks, particularly when navigating acute curves. Characteristics such as lightweight bogies, compact rubbered wheels, independent wheel systems, low platforms, and grooved rails further complicate tramway dynamics. While previous studies have explored various strategies to optimize wheel-rail contact parameters and profile designs for reducing wear, the focus has predominantly been on heavy railway systems and high-speed trains, with tram wheels and rails receiving comparatively less attention.

In light of the expanding tram market, driven by advantages such as low construction costs, space-sharing capabilities with other transportation modes, and improved accessibility for vulnerable passengers, there is a growing demand for tramway-oriented research. Addressing this need, the present study introduces a novel strategy to comprehensively assess the sensitivity of morphing tram wheel profiles in minimizing wear and derailment risks.

Using the multi-physics simulation tool Simpack, tram vehicles are digitally recreated to replicate real-world testbed scenarios, encompassing sharply curved lanes. The baseline performance is validated against experimental field data, considering vibrational excitations. Parameterization of six key components within the wheel profile - flange height, inner and outer flange angles, flange corner roundness, top surface roundness, and surface angle - facilitates the exploration of various profile designs. A comprehensive review determines the boundaries of variation for each variable.

An automated design algorithm generates diverse profile shapes based on selected input variables. Key quantities of interest (QoIs), including wear index and derailment coefficient, are computed to evaluate the performance of different profile designs. Preliminary variable screening, employing the Morris Factorial Method, identifies the most influential parameters, thereby streamlining the exploration process. This step designates three key properties for observation out of all six.

After a comparable review of meta-modeling techniques including RBF, Kriging, etc., the Elliptical Basis Function is demonstrated to efficiently capture multidimensional effects. The surrogating process iterates efficiently until the disparities between predicted and simulated training points are minimized toward the target threshold. A comprehensive analysis of parametric influences is conducted. Coupled with these effects, optimal profiles are finally determined for two OoIs, showcasing improved dynamic performance compared to baseline designs through extensive simulation studies.

This research significantly contributes to understanding tram wheel profiles, offering a numerical strategy to complement physical testing methodologies. Moreover, it lays the groundwork for future advancements in enhanced profile design strategies, ultimately enhancing the safety and efficiency of tram operations.

Presenting Author: Sangyup Lee Korea Railroad Research Institute

Presenting Author Biography: Dr.Lee mainly studys dynamic system and applied physics at Korea Railroad Research Institute(KRRI). He got his Ph.D. degree (Mechanical Engineering) for multiscale methodology of shockphysics from University of Texas at Asutin. He has also studied modeling and simulation fornonlinear physics as a researcher at Georgia Tech before KRRI.

Authors:

Sangyup Lee Korea Railroad Research Institute
Kyoungjoon Choi Korea Railroad Research Institute