FB-SIM. An open-source virtual-SIMulator of Faulted Bearings in real operational conditions

Significance 

Mechanical elements, gears and rolling bearings susceptible to wear and failures. This is because of the relative motion between the machine elements. As such various techniques like temperature monitoring and chemical content analysis have been developed to analyze and monitor the condition of machine bearings. However, vibration analysis is the main method used despite the noise and disturbances. Therefore, researchers have developed numerous algorithms with the aim of achieving clear signals, by eliminating the vibration disturbances, to monitor the health conditions of bearings. They provide both real-time measurements and simulated results. Unfortunately, unlike the simulated results which are readily available as open source for post-processing, real measurements results and not that common.

Previously epicyclic gear-like model was proposed to determine the faulted bearing simulation signals. It enabled the evaluation of the fault frequency characteristics resulting from damaged bearings. Owing to the limitations of the method like the slippery effect occurring at the contacts of the bearings and other components, various improvements have been initiated to improve their efficiency. For instance, the vibration signal model have been modeled as a cyclostationary signal with a periodic autocorrection function. It provides a better description of the slippery effects which was the main drawback of the initial models. Consequently, recently developed models have also taken into consideration the load and speed variations in the machine conditions thus improving their efficiency and reliability. Unfortunately, due to the complex nature of the models, the algorithms have become more complex hence difficult to implement.

Dr. Gianluca D’Elia and Professor Emiliano Mucchi at the University of Ferrara in collaboration with Dr. Marco Cocconcelli at University of Modena and Reggio Emilia developed a novel algorithm to simulate the vibration signals of a faulted bearing. The model was an improvement of the model proposed by Prof. Jerome Antoni (University of Lyon), including extending the constant speed operation to variable speed and developing new mathematical formulation. The simulation is an open source high-level language similar to Matlab. The authors’ main aim was to develop a universal model acceptable to the researchers’ community for conditions monitoring. Their work is published in the journal, Meccanica.

The authors observed that the developed model could be used by various readers and researchers to simulate various bearing faults and operating conditions because it is based on an open-source algorithm. Consequently, a similar resonance frequency was recorded for both the stimulation signal and the experimental data. All the expected feature and additional improvements were effectively analyzed and proved.

The developed novel model has successfully addressed the challenges of the initial models. For example, it allows the user to set various features including selection of the fault location, selection of the fault stage, signal cyclostationarity, deterministic contributions, random contributions, the machine working condition either as stationary or non-stationary and the effect of the resonances. Therefore, the study is a foundation for the realization of universally accepted tools for condition monitoring and diagnosis techniques in machines.

About the author

Marco Cocconcelli was born in Italy on 1977. He received the M.S. degree in mechanical engineering and the Ph.D. degree in applied mechanics from the University of Bologna, Bologna, Italy, in 2003 and 2007, respectively. In 2007, he joined the University of Modena and Reggio Emilia, Reggio Emilia, Italy, where he is currently a Researcher in Applied Mechanics at the Department of Sciences and Methods of Engineering. His research interests include bearing and gear diagnostics, condition monitoring in stationary and non-stationary conditions. He holds one international patent on predictive rolling bearing maintenance.

About the author

Emiliano Mucchi was born in Italia on 1979. He received the M.S. degree in Material Engineering and the Ph.D. degree in Applied Mechanics from the University of Ferrara, Italy, in 2003 and 2007, respectively. In 2007, he joined the University of Ferrara where he is currently Associate Professor in Applied Mechanics at the Engineering Department. His scientific activity is mainly in the field of Noise and Vibrations of Machines, with particular reference to elastodynamic models, condition monitoring, diagnostics and experimental vibration measurements. In 2005 and 2007 he was guest at the Katholieke Universiteit Leuven (Belgium) addressing researches on novel approaches for simplified FE model and vibro-acoustic experimental analyses in helicopters. Prof. Mucchi is a member of ASME and Member of several Editorial Boards of International Journals.

About the author

Gianluca D’Elia was born in Italy on 1980. He received the M.S. degree in Material Engineering and the Ph.D. degree in Applied Mechanics from the University of Bologna, Italy, in 2004 and 2008, respectively. In 2008, he joined the University of Ferrara where he is currently a Researcher in Applied Mechanics at the Engineering Department. He was guest at the Institute of Sound and Vibration Research – University of Southampton – with a Marie Curie Hosing Fellowships, and assistant research engineer at the Universitè de Technologie de Compiègne under the supervision of Prof J. Antoni. His scientific activity is mainly in the field of signal processing for the diagnostics of rotating machines, with particular reference to time-frequency analysis and Cyclostationary analysis.

Reference

D’Elia, G., Cocconcelli, M., & Mucchi, E. (2017). An algorithm for the simulation of faulted bearings in non-stationary conditionsMeccanica53(4-5), 1147-1166.

Go To Meccanica

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