Cristoforo Demartino

Assessment of the Peak Response of a 5MW HAWT Under Combined Wind and Seismic Induced Loads

The rapid growth of the wind energy industry has brought the construction of large-scale wind turbines with the aim of increasing their performance and profits to areas characterized by high seismic hazard. Previous research demonstrated the seismic vulnerability of large-scale wind turbines when seismic and wind actions are considered simultaneously in the demand model. In this study, the response of the supporting structure of a land-based horizontal axis wind turbine under the combined effects induced by wind and earthquake is presented.

Deterministic and Probabilistic Serviceability Assessment of Footbridge Vibrations due to a Single Walker Crossing

This paper presents a numerical study on the deterministic and probabilistic serviceability assessment of footbridge vibrations due to a single walker crossing. The dynamic response of the footbridge is analyzed by means of modal analysis, considering only the first lateral and vertical modes. Single span footbridges with uniform mass distribution are considered, with different values of the span length, natural frequencies, mass, and structural damping and with different support conditions. The load induced by a single walker crossing the footbridge is modeled as a moving sinusoidal force either in the lateral or in the vertical direction. The variability of the characteristics of the load induced by walkers is modeled using probability distributions taken from the literature defining a Standard Population of walkers. Deterministic and probabilistic approaches were adopted to assess the peak response. Based on the results of the simulations, deterministic and probabilistic vibration serviceability assessment methods are proposed, not requiring numerical analyses. Finally, an example of the application of the proposed method to a truss steel footbridge is presented. The results highlight the advantages of the probabilistic procedure in terms of reliability quantification.