چكيده به لاتين
Abstract
The development of high-speed trains and consequently the increase in the use of slab-tracks as reliable and long lasting tracks in rail transport infrastructure has led the to the study of the impact of various forces including vertical and lateral and axial forces(Longitudinal) that affect these lines become necessary. Longitudinal forces are caused by changes in temperature due to contraction and expansion of the rail (thermal forces), acceleration and braking forces in wagons and locomotives, and many other factors. Failure to control these forces may reduce the stability of the track and lead to the Derailment of the track, resulting in significant damage to passengers and trains. Due to the dynamic essence of the track and train interaction problem, the researchers are forced to dynamically analyze the effects of different forces on the railway. The dynamic analysis of train and track interactions, especially in recent years, has attracted the interest of many researchers, especially railway engineers.
In the present study, after referring to the technical literature of the subject, the method for modeling the slab-track with finite element method and solving dynamic motion of train on slab-track with Newmark-Beta numerical method to has been discussed. In the following, the effects of different values of longitudinal axial forces on the dynamic response of the slab-track along with changing various parameters of the line such as rail irrigulrity, stiffness of the pad and fastening system and the speed of the train, are presented in charts.
in this research, the axial force was applied in both tensile and compressive. Applying the compressive force increased the displacement, acceleration of the rails and the contact force of the wheels and rails. Also Applying the tensile force reduced rail displacement, rail acceleration and wheel and rail contact force. The results of this study showed that the changes of the rail acceleration is greater than rail displacement and wheel rail contact force. The results also showed that increasing the stifness of the fasteners and the pad under the rails reduce the effects of axial force on the slab, which can be used as a tool to control these effects at tropical regions.
Keywords: Slab Track and Train Dynamic Interaction, Axial Force Effects on Railway track , Longitudinal Force, Railway Dynamic Analysis
