Numerical and Experimental Dynamic Analysis of IC Engine Test Beds Equipped with Highly Flexible Couplings

Driveline components connected to internal combustion engines can be critically loaded by dynamic forces due to motion irregularity. In particular, flexible couplings used in engine test rig are usually subjected to high levels of torsional oscillations and time-varying torque. This could lead to premature failure of the test rig. In this work an effective methodology for the estimation of the dynamic behavior of highly flexible couplings in real operational conditions is presented in order to prevent unwanted halts. The methodology addresses a combination of numerical models and experimental measurements. In particular, two mathematical models of the engine test rig were developed: a torsional lumped-parameter model for the estimation of the torsional dynamic behavior in operative conditions and a finite element model for the estimation of the natural frequencies of the coupling. The experimental campaign addressed torsional vibration measurements in order to characterize the driveline dynamic behavior as well as validate the models. The measurements were achieved by a coder-based technique using optical sensors and zebra tapes. Eventually, the validated models were used to evaluate the effect of design modifications of the coupling elements in terms of natural frequencies (torsional and bending), torsional vibration amplitude, and power loss in the couplings

2nd Conference on Condition Monitoring of Machinery in Non Stationary Operations (CMMNO’2012)

Member of the Scientific Committee of the 2nd Conference on Condition Monitoring of Machinery in Non Stationary Operations (CMMNO’2012), Tunisia, 201

7th International Conference Surveillance

Member of the Scientific Committee of the 7th International Conference Surveillance, Chartres (France), 2013

3rd International Conference on Condition Monitoring of Machinery in Non-Stationary Operations (CMMNO 2013)

General Chairman di 3rd International Conference on Condition Monitoring of Machinery in Non-Stationary Operations (CMMNO 2013), May 8-10, 2013, Ferrara, Ital

VERSO IL MOTORE VIRTUALE – SVILUPPO DI METODOLOGIE NVH SPECIFICHE PER I MOTORI DIESEL, LORO IMPLEMENTAZIONE IN PROCEDURE APPLICATIVE ALL’INTERNO DELLA VM MOTORI E TRASFERIMENTO DEL KNOW-HOW AL PROPRIO PERSONALE ADDETTO.

none1TRATTASI DI UN CONTRATTO DI RICERCA STIPULATO TRA IL DIP. DI INGEGNERIA E LA VM MOTORI PER LO SVILUPPO DI METODOLOGIE NVH SPECIFICHE PER I MOTORI DIESEL, LA LORO IMPLEMENTAZIONE IN PROCEDURE APPLICATIVE ALL’INTERNO DELLA VM MOTORI ED IL TRASFERIMENTO DEL KNOW-HOW AL PROPRIO PERSONALE ADDETTO.noneG. DALPIAZDalpiaz, Giorgi

6th International Conference on Acoustical and Vibratory Surveillance Methods and Diagnostic Techniques

Member of the Scientific Committee of the 6th International Conference on Acoustical and Vibratory Surveillance Methods and Diagnostic Techniques, Compiègne (France), 201

Dynamic simulations of the GenC pump behaviour for different oil bulk moduli, relief grooves dimensions and radial plays

Contratto stipulato tramite il Consorzio Ferrara Ricerche con la TRW Automotive GmbH - Dusseldorf (D) - per effettuare simulazioni del comportamento dinamico di pompe GenC al variare dei parametri

Caratterizzazione vibro-acustica sperimentale di invertitori marini

Contratto stipulato tramite il Consorzio Ferrara Ricerche con la Twin Disc Technodrive Srl per la caratterizzazione vibro-acustica sperimentale di invertitori marini

Vibration-based bearing fault detection and diagnosis via image recognition technique under constant and variable speed conditions

This paper addresses the application of an image recognition technique for the detection and diagnosis of ball bearing faults in rotating electrical machines (REMs). The conventional bearing fault detection and diagnosis (BFDD) methods rely on extracting different features from either waveforms or spectra of vibration signals to detect and diagnose bearing faults. In this paper, a novel vibration-based BFDD via a probability plot (ProbPlot) image recognition technique under constant and variable speed conditions is proposed. The proposed technique is based on the absolute value principal component analysis (AVPCA), namely, ProbPlot via image recognition using the AVPCA (ProbPlot via IR-AVPCA) technique. A comparison of the features (images) obtained: (1) directly in the time domain from the original raw data of the vibration signals; (2) by capturing the Fast Fourier Transformation (FFT) of the vibration signals; or (3) by generating the probability plot (ProbPlot) of the vibration signals as proposed in this paper, is considered. A set of realistic bearing faults (i.e., outer-race fault, inner-race fault, and balls fault) are experimentally considered to evaluate the performance and effectiveness of the proposed ProbPlot via the IR-AVPCA method

Incoming stall identification in axial compressors by vibration analysis

This work addresses on a complete vibro-acoustic characterization of an axial compressor with the aim to foresee the rotor instability. The tests were performed on a turboshaft Allison 250-C18. The compressor is composed of six axial stages and one centrifugal stage. Four vibration signals were simultaneously measured by means of accelerometers, while the acoustic signals were measured by means of two microphones. Two different kinds of tests have been carried out on the compressor that operates at constant speed: in the course of the first test the six signals were acquired at different positions of the throttle opening, whereas during the second test, the signals were acquired while the throttle was gradually opened. The test results show a sensitive increase of the sub-synchronous activity in the accelerometers spectrum map, moreover, closing the throttle, the amplitude of the spectrum components increases. These phenomena can be related to the rotating stall behavio