acceleration-based quality assessment of railway tracks using a 2d simulation model and recorded track data

car body acceleration is an important factor affecting track safety and ride comfort, which are two primary aspects of railway systems. though track level is an important source of wagon body acceleration, no quantitative relation between them is available and the aim of this paper is to propose a method to address this issue. to do so, car body acceleration is determined using a 10 dof simulated wagon, when track level irregularity is applied to its wheels. results of numerical 2d simulation suggest an increasing trend between track level irregularity and car body acceleration. this trend is also affected by the quality of tracks, as higher acceleration levels are evident in tracks with poor quality condition. to have a more realistic point of view, a case study of iranian network is carried out in which recorded acceleration and track level data of em120 recording vehicle are used to determine the trend between them. acceleration levels obtained through this method are higher than those obtained by simple 2d model, since all affecting factors are introduced. also, results suggest that for any value of track level irregularity, acceleration is bounded to an upper and lower level, which are obtained using a linear regression. a new track quality assessment based on recorded car body acceleration level is also proposed.