Investigating the relations proposed for the dynamic impact factor in the railway (in terms of velocity parameter of the railway vehicle)

Document Type : Original Article


1 Department of Railway Engineering and Transportation Planning, Faculty of Civil and Transportation Engineering, Isfahan University, Isfahan, Iran

2 Department of Mechanical Engineering, Faculty of Technical and Engineering, Isfahan University, Isfahan, Iran


Railways experience dynamic vertical forces due to their transitive nature and the presence of faults and failures in both the rail infrastructure and vehicles. Precisely determining these forces, considering their dynamic effects, is a time-consuming process. For design purposes, vertical forces are often treated as quasi-static. The quasi-static force of a railway wheel, which includes dynamic impacts, is calculated by multiplying the static force (total weight of the vehicle divided by the number of wheels) by an increasing dynamic impact factor coefficient. Various relationships have been proposed by institutions and researchers in the rail transport industry to calculate this dynamic impact factor, with a focus on those considering the railway vehicle's velocity. The study reveals that Talbot's formula recommends cautious measures for dynamic impact coefficients at speeds exceeding 44 km/h, and Mir Mohammad Sadeghi's formula suggests the smallest values for speeds above 84 km/h when compared to other formulas.


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