Curved sections of track and trains with a car body tilt

Abstract

On the railway, one of the bottlenecks in increasing the speed of trains are curved sections of track. When passing such sections by the crew, a centrifugal force arises, which is proportional to the square of the speed and inversely proportional to the radius of the circular curve. This force is partially neutralized by elevation of the outer rail in the curve. There is a so-called outstanding acceleration, the magnitude of which is limited by technical conditions. On high-speed railways, when the permissible outstanding acceleration acting on the passenger is exceeded, trains with a car body tilt are operated to neutralize this acceleration. The tilt of the body can be passive due to centrifugal forces and active with the help of special tilt mechanisms. In any case, the tilt speed should be linked to the process of passing the curved section by train. It is shown that the use of the biclotoid curve design smooths the inertia of the kinetics of the car body tilt. Biclotoid design is the design of a curved section with two transition curves butt-to-butt, without a regular circular curve. Such a design reduces the forces of interaction between the wheel and the rail, increases the smoothness of the train movement, which makes it easier to adapt the process of tilting of the body to the passage of a curved section by train. It is proposed to take into account the concept of “force impulse”. This will allow, at high speeds, to use a more technically permissible outstanding acceleration equal to 0.4 m/s2.