A study regarding the safety against crosswinds of a high-speed train running over a railway bridge belonging to the future high-speed railway network in Russia is presented. The dynamic analyses are performed using a software named VSI - Vehicle-Structure Interaction Analysis developed by the first authors. The wind load is applied to the bridge and train using a practical methodology based on a discrete gust model, thus avoiding the generation of complex stochastic wind models. The dynamic response of both the bridge and train is assessed and the running safety criteria evaluated. Two different bridge structural solutions have been proposed by the designer. Therefore, the results obtained on these two structural solutions are compared and the limit values for the train speed for each analyzed wind speed are defined based on the running safety criteria allowances defined in the codes.

Purpose: The purpose of this paper is to evaluate the fatigue process through the dynamic analysis of the global structural model and local static sub-modelling in a critical detail using the hot-spot stress approach. The detail was studied in three different positions at the “Alcácer do Sal” access viaduct, and the methodologies from the IIW and Eurocode EN 1993-1-9 were compared. Design/methodology/approach: In this study, the fatigue life process based on the hot-spot stress approach was evaluated using a global dynamic analysis and a local sub-modelling based on a static analysis of welded connections in the “Alcácer do Sal” railway structure, Portugal, taking into consideration the recommendations from IIW and Eurocode EN 1993-1-9. The hot-spot stresses were calculated through the static analysis of the sub-model of the welded connection for each vibration mode with the aim to obtain the temporal stresses using the modal coordinates and modal stresses of the extrapolation points. The Ansys® and Matlab® softwares were used for the numerical analysis and the hot-spot stress calculations, respectively. Findings: The proposed methodology/approach to obtain fatigue assessment is based on the modal analysis of the global structural model and local static sub-modelling. The modal analysis was used to extract the boundary conditions to be used in the local model to determine the temporal stresses of the extrapolation points. Based on the modal superposition method, the stresses as function of time were obtained for fatigue life evaluation of a critical detail by the hot-spot stress approach. The detail was studied in three different positions. Originality/value: In the present study, a global-local fatigue methodology based on dynamic analysis of the global structural model and local static sub-modelling of the critical detail using the hot-spot stress approach is proposed. Herein, the modal analysis of the global structural model supported by the modal superposition method was used to obtain the matrix of modal coordinates. The static analysis of the local sub-model for each mode from the modal analysis of global structural model was done to estimate the hot-spot stresses. The fatigue damage calculation was based on S-N curve of the critical detail and rainflow method. The IIW recommendation proved to be more conservative compared to the proposed rules in the Eurocode EN 1993-1-9. The global-local modelling based on dynamic analysis is an important and effective tool for fatigue evaluation in welded joints.

Bridges constitute an important part of the infrastructure and are subjected to damage and deterioration of materials and support conditions, as well as exposure to adverse environmental conditions. Continuous or repeated monitoring of structural responses may add important information for decision-making regarding their maintenance, repair and reinforcement. The use of these data, in conjunction with techniques of structural reliability for the treatment of the uncertainties, allows a better understanding of the structural behaviour and integrity. Modern Information and Communication Technologies can greatly contribute to the improvement of the maintenance capacity and, consequently, to the reliability of the assets and to their operational availability. New wireless communication technologies, such as 5 G networks, are considered as the enabling technologies of the digital transformation, integrated with the concept of the Internet of Things. High connectivity capacity and intensive automation enable, for example, changes in inspection paradigms and asset maintenance, by transferring the product focus to service platforms, bringing gains to productivity, comfort, operational safety and costs. New predictive maintenance approaches, which make use of a large amount of data available, can improve the efficiency of maintenance processes, producing more accurate and reliable anticipated diagnostics. The Digital Twins incorporate all these tools and allow a real-time view of the evolution of the asset behaviour. This concept applied to a railway bridge is presented and discussed in detail in this paper.