Prof. Francesco Ripamonti

This paper introduces a measurement technique aimed at reducing or possibly eliminating the spatial aliasing problem in the beamforming technique. Beamforming main disadvantages are a poor spatial resolution, at low frequency, and the spatial aliasing problem, at higher frequency, leading to the identification of false sources. The idea is to move the microphone array during the measurement operation. In this paper, the proposed approach is theoretically and numerically investigated by means of simple sound propagation models, proving its efficiency in reducing the spatial aliasing. A number of different array configurations are numerically investigated together with the most important parameters governing this measurement technique. A set of numerical results concerning the case of a planar rotating array is shown, together with a first experimental validation of the method.

23 April 2019 in Journal of Vibration and Control

Journal Article

A smart solution for improving ride comfort in high-speed railway vehicles

Francesco Ripamonti

A. Chiarabaglio

The secondary suspensions of high-speed trains are designed to guarantee high comfort levels to passengers by reducing the perceived vibrations. Recent studies have shown that, besides the vertical and rigid pitch motions, the first deformable modes of the car-body are very important when dealing with comfort. Therefore, the suspension damper has to offer high performances at low frequencies, but at the same time, has to transmit low force at high frequencies. To achieve this target, in this work, a traditional passive oil damper was modified. A proper servo-valve was installed between the two chambers of the damper, and three different control logics were studied. A hardware-in-the-loop test bench was created and the proposed solutions were compared in terms of comfort improvement.

About Me

Francesco Ripamonti is associate professor of applied mechanics at the Department of Mechanical Engineering of Politecnico di Milano. In December 2002, he graduated with a degree in mechanical engineering at Politecnico di Milano, and in March 2006, he completed his PhD studies in mechanical systems engineering. Since June 2006, he has been employed at the Politecnico di Milano (Department of Mechanical Engineering), where he is currently teaching applied mechanics and vibration analysis and vibroacoustics. His main research activities deal with the dynamics and control of mechanical systems, vibroacoustics, smart materials and structures, rail and road vehicle NVH, and cable dynamics. He is coordinator of the Cable Dynamics laboratory of the Mechanical Engineering Department, aimed at the numerical and experimental study of the dynamics of overhead lines (conductors and related fittings). He participated in five research projects funded by the EU or national/regional grants. He is the author of over 80 scientific publications and 13 patents.

Prof. Francesco Ripamonti

Prof. Francesco Ripamonti

Research Focus & Metrics

Academic Career Length

Publication Type Breakdown

Representative Publications

About Me