Simulation tests of dynamics of vibroisolated railway lines with vibroisolating system based on elastomer elements

Badania symulacyjne dynamiki wibroizolowanych linii kolejowych z układem wibroizolacyjnym na bazie elementów elastomerowych

Abstract

The problem of propagation of vibration waves caused by the movement of rail vehicles in the ground is extremely important from the point of view of environmental protection against negative effects of dynamic impacts caused by rail transport. Therefore, there is a need to develop new methods for analyzing dynamic phenomena related to rail vehicle traffic. One of the methods that can be used to evaluate dynamic interactions is modeling using finite elements. The article presents a dynamic analysis of the track structure model and the impact of the application of its vibroisolation system on the level of ground vibration amplitude associated with the propagation of vibration waves from the track. The application of the finite element method allows for the analysis of the behavior of engineering structures in variable operating conditions dependent primarily on the speed of movement of vehicles on the track. Such analysis includes the use of a number of physical values ​​that can be used to assess the impact of vibration on any engineering object. These values ​​include, above all, acceleration at any measuring point on the measurement cross-section from the track to the engineering construction, e.g. a residential or industrial building as well as displacement or stress, which are dependent on the speed of the rail vehicle. Comparison of these values ​​with generally available criteria and standards allows at the stage of designing the engineering structure for appropriate modifications to the substructure construction to limit the amplitude of the vibrations transmitted to the environment. These modifications consist mainly of the use of an appropriate vibroisolation system in the form of, for example, slabs or mats laid in the rail layer or pads underneath. Correct execution of the simulation requires careful preparation of the numerical model as well as a series of input data. The input data relate mainly to accurate material data concerning both engineering structures (bridges, viaducts, tunnels), rolling stock and soil parameters. Such data allow to prepare a spectrum of forces loading the modelled section of the track. This approach to the design process is particularly important due to the inability to modify the track after built it.