INFLUENCES OF SKIDDING PATTERN UPON THE OCCURRENCES OF SKID DAMAGE TORAILWAY WHEELS

Wheel skidding happens easily on braking when moisture and contaminant s remain on the railhead. Then wheel-flat damage is liable to occur. T his study was carried out to search for an appropriate skidding patter n by which the wheel flat would be reproduced experimentally. A two-ro ller type of testing machine, which suitably incorporates a skidding d evice, was designed and manufactured for the test. The device can give rise to wheel skidding either by the lubricant feeding to the contact zone of wheel and rail or by the application of the brake to the whee l specimen axle. Various patterns of wheel skidding are generated depe nding upon the lubricant, contact stress, skidding time and the brake operation. It is necessary for the wheel-flat reproduction to arrange a skidding condition in which severe wear is suppressed and the temper ature of the skidding surfaces rises gradually. Stoppage of the wheel specimen is a useful technique to reproduce various degrees of flat da mage.