Papers by Keyword: Wheel/Rail Contact

Abstract: The aim of the article is to present the necessity of completion of the test stand of brake components of railway vehicles with the equivalent railway operation load simulator for the research of the wheel wear on it. The other aim of presented research needs is to perform the analysis of the equivalent conicity as a parameter for the rail vehicles in operation ride properties prediction. The sub aims are the change of frame, wheel, braking forces load via SIMRAIL simulator program load collection performance.

Abstract: The articles deals with the way of calculation of tangential stresses over non-elliptical contact patch, where is possible to utilize with advantage the Kalkers simplified method FASTSIM. This method named FASTSTRIP is adapted for non-elliptical contact area calculated by means of the Strip method. This method is almost quick as FASTSIM and the results are similar to the CONTACT results. This method may be useful for rail vehicles in track dynamics computation.

Abstract: An important parameter influencing the power effect of a wheel on the rail is the size and shape of the contact area as well as the normal stress distribution which has the impact on it. Nowadays various methods are used to find out the size of contact areas and stresses [. It is necessary to mention the Hertz method as one of the oldest up to date used methods. It provides acceptable results for a large area in spite of many simplifications. Another computational procedure is the Kalker variation method [ or the strip method [ which is, thanks to its results, close to reality and is used in the following calculations. Nowadays, another group of calculation program systems (ANSYS, ADINA) is used in certain situations. The systems work on the base of finite elements method theory.

Abstract: Reduction of noise due to rolling contact of wheel and rail for fright cars is one of the principal tasks of the European railways to be solved. Experts of railways, industries and universities were engaged during the last about ten years to search for technical solutions. An important noise reduction of fright cars can be achieved by replacing the cast iron brake shoes by composite brake shoes. Doing that, two directions have been taken into consideration. This is due to the fact, that at that time most composite brake shoes were based on friction coefficients were far away from that ones of the cast iron brake shoes. Applying such friction materials on existing vehicles would have as a consequence the change of braking forces acting on the wheels. These types of brake shoes (K-block) show a friction coefficient which is higher than that one of cast iron. As a consequence the application of the silent composite brake blocks of type K affords the adaptation of the braking system of the vehicle, what is cost intensive. For these reason, the application of K-brake block was proposed for new built vehicles. For existing vehicles solutions having the same friction coefficient as the cast iron brake shoes were requested (LL-Brake doing in this way, the modification of the braking equipment of existing fright cars could be avoided.

Abstract: Wheels of the railway vehicle play the important role for driving train through wheel-rail interaction. Especially wheel profile is one of the most important design factors to rule the running stability and safety of train. Accordingly, the control of rolling contact fatigue-related defects is an ongoing concern for both safety and cost reasons. This process is referred to as ratcheting. Wear of wheel and rail surfaces occur due to a mixture of adhesive, abrasive and corrosive processes. In wheel/rail systems with little wear, such failure is manifested by the appearance of closely spaced micro-cracks. In the present paper, a evaluation of surface defects of wheel and rail for Korean high-speed railway. The main research application is the wheel-rail maintenance of Korea high-speed train.