軌道車輛及軌道承托系統之破壞型態及案例探討

Failure Mechanisms and Case Studies for Rail Vehicles & Track Support Systems

軌道系統擔負重要之人員運輸的角色，軌道的安全要求相對也較高。目前國內的軌道系統不論是鐵路、高速鐵路、捷運或輕軌系統，除了自然老化的狀況外，也常因國外公司設計、材料選用、組件的製造條件不盡然適用於國內高溫潮濕的場域；或是組件及系統的組裝與建置因面臨國外與國內公司聯合承攬的情況，產生工法之適用性及品質完備性的疑慮，而有組件或系統提早失效的情況。軌道系統破壞機制有製造缺陷、潛變、疲勞、磨耗、腐蝕、以及焊接不良等。本篇論文就軌道車輛及軌道承托系統常見之破壞型態進行分析，並就國內兩起實例進行探討，其中一案為列車車輪之破裂，另一案為軌道岔心鋼軌開裂的例子；此兩案主要的破壞機制均為疲勞，而加速疲勞破壞的原因分別為操作人員未均循標準作業程序，以及焊接不良所造成。案例探討的目地是希望藉由事故分析的結果，能提供軌道系統之規劃、建造、操作與維護階段的借鏡，以降低早期失效的風險。

Most of the original designs and major components of our domestic railways, high-speed railways, MRT or light rail systems are imported from foreign companies. So, the material selection, the manufacturing conditions of components, or the assembly of components and systems may face the different high-temperature and humid fields compared to the original design considerations. Furthermore, due to the situation of joint construction with foreign and domestic companies, there are doubts about the applicability of the work methods and the completeness of the quality, and there are cases where components or systems fail prematurely. The failure mechanisms of the railway systems have manufacturing defects, creep, fatigue, wear, corrosion, and poor welding, etc. This paper analyzes the common failure modes of rail vehicles and track support systems, and discusses two examples in Taiwan. One of which is the breakdown of train wheels, and the other is an example of cracking of track rails. The major failure mechanism of both cases is fatigue, and the causes of accelerated fatigue damage are caused by the failure of the operator to follow the standard operating procedures and poor welding. The case study and the results of the accident analysis are intended to provide a framework for the planning, construction, operation and maintenance phases of the railway system to reduce the risk of early failure.