چكيده به لاتين
Transport infrastructures such as railways is always exposed to vertical, lateral and axial loads (longitudinal) that are different for different types of railways. The temperature changes due to the contraction and expansion of the rail (thermal forces), the acceleration and braking forces in the wagons and locomotives, and many other factors cause the formation of high axial forces in the rail, which the lack of control of these forces may reduce the stability of the track and ultimately result in damage to passengers and train. Due to the dynamic nature of the interaction issue, researchers have been forced to dynamically analyze the effects of different types of forces on the railway. Dynamic analysis of train- track interaction has attracted many researchers, especially railway engineers, in recent years.
In the present study, the effects of non-application of longitudinal axial force, the application of longitudinal axial tensile force and the application of longitudinal compressive force on parameters such as displacement, speed and acceleration of the rail , velocity and acceleration of the sleeper ,velocity and acceleration of the ballast are investigated simultaneously with applying one dynamic vertical load and four dynamic vertical load and then analyzed by Sensitivity is obtained for various values of longitudinal force and for different velocities such as 10, 20, 50 and 100 m/s. Effect of these factors on the displacement, speed and acceleration of rails, sleepers and ballasts is presented in the form of diagrams. In general, the results of the studies showed that the increase of values Longitudinal axial force as well increase the speed of the train with applying one dynamic vertical load and also applying four dynamic vertical load actions to increase displacement, speed and acceleration of the rail , ballast and sleeper.
