Abstract

This report presents the results of an investigation into two methods of using the natural gas pipeline as a communication medium. The work addressed the need to develop secure system monitoring and control techniques between the field and control centers and to robotic devices in the pipeline. In the first method, the pipeline was treated as a microwave waveguide. In the second method, the pipe was treated as a leaky feeder or a multi-ground neutral and the signal was directly injected onto the metal pipe. These methods were tested on existing pipeline loops at UMR and Batelle. The results reported in this report indicate the feasibility of both methods. In addition, a few suitable communication link protocols for this network were analyzed. Document type: Report

Abstract

International audience; Based on the finite element method, the wave finite element method (WFE) permits to analyze the dynamics of a periodic structure by using a wave decomposition of one period. This method reduces the number of DOF and it has advantages in calculation time. However, it cannot be applied easily to a railway track because this structure is subjected by moving loads which are not considered in a classical WFE. In this article, we present a technique to deal with moving loads applying in a railway track where the track components are modeled by 3D continuous media. By using the classical WFE for one track period in frequency domain, we can rewrite the vector of DOF and loads in a wave base. Then, we can calculate the wave amplitudes of the moving loads from their representation in this base. Thereafter, we apply the wave analyze of WFE to the hold structure. The result shows that the moving loads lead to a sum of wave amplitudes. Finally, we apply this method for a railway track subjected to constant moving loads with numerical application. The new technique permits to analyze the dynamic of railway tracks by considering only one track period.