ON SURFACE FRACTURE OF RAIL HEADS

The Effect of Temperature on the Fracture Surface Morphology and Ductility of La55Al25Ni5Cu10Co5 BMG

In this research, the effect of temperature on the mean size of fracture surface features, as well as the relation between fracture surface morphologies and ductility of a La-based BMG as a relatively brittle alloy, was systematically investigated. After producing the alloy, three-point bending experiments, over a wide range of temperatures, were conducted on the samples; then the fracture surf...

Predicting Crack Initiation Due to Ratchetting in Rail Heads Using Critical Element Analysis

This paper presents a strategy to predict the lifetime of rails subjected to large rolling contact loads that induce ratchetting strains in the rail head. A critical element concept is used to calculate the number of loading cycles needed for crack initiation to occur in the rail head surface. In this technique the finite element method (FEM) is used to determine the maximum equivalent ratchett...

Discrimination and Enhancement of Fracture Signals on Surface Seismic Data

Controlling Rail Potential on Dc Supplied Rail Traction Systems

Most of the modern DC electrified mass transit systems use a totally floating earth as their grounding strategy. A well known problem related with totally floating systems is that the touch potentials can be dangerously high. In order to reduce the voltages on rails, several devices exist. Most of these devices allow a direct connection to earth when a certain voltage threshold is exceeded. In ...

Morphology Evolution on the Fracture Surface and Fracture Mechanisms of Multiphase Nanostructured ZrCu-Base Alloys

A multiphase nanostructured ZrCu-base bulk alloy which showed a unique microstructure consisting of sub-micrometer scale Zr₂Cu solid solution, nano-sized twinned plate-like ZrCu martensite (ZrCu (M)), and retained ZrCu (B2) austenite was fabricated by copper mold casting. The observation of periodic morphology evolution on the fracture surface of the multiphase nanostructured ZrCu-base alloys h...