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The assessment of the location and the extension of cracks in roads is important for determining the potential level of deterioration in the road overall and in the infrastructure buried beneath it. Damage in a pavement structure is usually initiated in the tarmac layers, making Rayleigh waves ideally suited for the detection of shallow surface defects. Assessment of crack in roads is usually performed assuming constant velocity and non-dispersive behaviour of the material tested, limiting this approach to the very shallow layer of the road. In this work, differences between the spectral images obtained with the Multichannel Analysis of Surface Waves (MASW) and the Multiple Impact of Surface Waves (MISW) are exploited for the first time to detect, locate and evaluate

Assessment of the location and extension of cracking in road surfaces is important for determining the potential level of deterioration in the road and in the infrastructure buried beneath it. Damage in a pavement structure is usually initiated in the asphalt layers, making the Rayleigh wave ideally suited to the detection of shallow surface defects. However, the practical application of crack detection methods in asphalt is hampered by the dispersive behaviour of the road pavement. In fact, assessment of crack in road is usually performed assuming constant phase velocity, and its dispersive behaviour is neglected. Moreover, current methodologies for crack evaluation in asphalt do not support in-situ applications. A new digital signal processing technique for the measurement of the amplitude and phase of the direct and reflected Rayleigh waves, scattered from the boundaries of a vertical crack in asphalt, is presented in this paper for the first time. It decomposes the signal into its in-situ crack evaluation of roads, for which the road is holistically treated as a dispersive medium.

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In this paper, the design of a vibration-based energy harvester mounted on the railway pantograph is discussed. The system aims to feed the diagnostic system of the pantograph-catenary interaction by recovering energy from the vibrations of the pantograph head itself. The design of the system is developed through a multiphysics finite element model, parametrized by means of experimental tests. The performance of the optimized solution, in terms of generated power, highlights the affability of the proposed solution.