Effects of ice and snow on nonlinear dynamic phenomena of railway overhead contact wire interconnected with electrification mast structures

Rail transit expansion, particularly in cold climates, has raised practical concerns about ice accumulation on overhead catenary systems, which can cause severe asset failure and service disruption. Recent studies have primarily modelled linear pantograph-catenary dynamics under icing conditions. This study aims to investigate the influence of geometric non-linearities and increased ice formation on the dynamic performance of a validated pantograph-catenary system. Ice formation was modelled by increasing the contact wire's density, and the catenary system was modelled using non-linear finite elements for the droppers, contact, and messenger wires. Unlike linear models, contact loss occurred at lower ice thicknesses and exhibited a stronger non-linear relationship. Although greater ice thicknesses generally increased contact wire displacement, acceleration trends showed high variation. Modal analysis of damped frequencies suggested that pantograph vibrations induced these variations rather than changes in catenary modes. These novel findings reveal a more pronounced non-linear dynamic response than previously reported and emphasise the importance of further developing ice formulation and modelling methods to mitigate failures such as those seen in Slovenia's 2014 icing event.