Rail Contact Stress Analysis And Optimization Of Rail Profile Shape

Rail operations will cause uneven abrasion on the surface of the rail and then affect train operation, deteriorate traffic conditions. Rail grinding is an effective way to improve state of wheel/rail contact and optimize driving conditions. In this paper, it is first to analyze and summarize the principle and method of rail grinding, and then calculate the advantages and disadvantages of Hertz algorithm and compared with the finite element algorithm from the perspective of contact stress. Finally, draw the conclusion that Hertz algorithm has the high computational time and can get the wheel/rail contact stress quickly and it is also convenient for modular design. but it does have some disadvantages, such as too many assumptions, poor adaptability, and it exists the more calculation error for the irregular rail surfaces after the abration;Finite element algorithm has a good simulation of the rail profile type after abrasion and has a good adaptability and a relatively small calculation error, but it also has some disadvantages, such as large computational effort, serious cost machine-hour and so on.Based on the research of rail grinding at the present stage, through summarizing the research achievements of rail profile optimization at home and abroad, it brought forward a new method of Rail profile optimization aim at increasing the wheel/rail contact area and reducing the first derivative differential value of wheel/rail outline to optimize the abrasion rail surface and reduce the wheel/rail contact stress. Then program the relevant procedure using matlab language, according to the idea of the sequence quadratic programming method, by calling the internal fmincon function, then get the optimal profile rail type by iteration. Through comparing before and after optimization of rail profile type, analysis and comparison before and after the optimization of the rail face in wheel/rail contact stress distribution by using Hertz algorithm and finite element algorithm respectively. It obtains that it can greatly improve the wheel/rail contact stress by "Minimum slope difference method" in this paper, if we optimize the shape of the abrasion rail by using the proposed theory, the optimal profile type of rail is reasonable.