| Abstract: | This article demonstrates a practical application of the structural articulation method. An existing prototype railway bridge was selected to compare our new method with the industry codes of practice. The response history and dynamic increment of the bridge were investigated through a variety of methods: lump sum mass analysis (LSMA) and suspension system analysis (SSA) for a single-axle force, and SSA for multi-axle forces. We considered both a local irregularity and a global sinusoidal irregularity. The dynamic impact load induced by either form of track irregularity increases approximately linearly with the vehicle speed up to a certain point, then tends to decrease gradually. This behaviour reveals that the dynamic impact load induced by track irregularities is dominated by the resonance of the bridge. If a bridge must support multiple axles, or if an especially accurate dynamic impact factor is required for safety reasons, then multi-axle SSA is recommended because this approach is the most accurate and likely to produce a weaker response than single-axle analysis. The random irregularity is generated by the stochastic track irregularity process. It is found that the dynamic impact load induced by the random irregularity is negligible, compared with the deterministic irregularity. |
