Alessandro Zanarini

Alessandro Zanarini
University of Bologna | UNIBO · Department of Industrial Engineering DIN

PhD. MSc.

About

54
Publications
28,037
Reads
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285
Citations
Additional affiliations
January 2013 - July 2015
TU Wien
Position
  • Experienced Researcher
Description
  • Marie Curie FP7-PEOPLE-IEF-2011 Project TEFFMA Towards Experimental Full Field Modal Analysis (http://cordis.europa.eu/project/rcn/103580_it.html) https://www.colorazeta.it/EngResearch/Zanarini_ricerca_EN.htm
October 2009 - December 2009
TU Wien
Position
  • Senior Lecturer / Visiting Professor
Description
  • 325.030 Advanced techniques in applied modal analysis and vibro-acoustic modelling https://www.colorazeta.it/EngResearch/Zanarini_didattica_EN.htm
April 2009 - June 2009
TU Wien
Position
  • Senior Lecturer / Visiting Professor
Description
  • 325.026 Complementary approaches in structural dynamics and experimental modelling http://www.diem.ing.unibo.it/personale/zanarini/Zanarini_didattica_EN.htm

Publications

Publications (54)
Article
The progress of optical systems gives nowadays at disposal on lightweight structures complex dynamic measurements and modal tests, each with its own advantages, drawbacks and preferred usage domains. It is thus more easy than before to obtain highly spatially defined vibration patterns for many applications in vibration engineering, testing and gen...
Article
We might doubt if optical measurements and spatially dense datasets are really effective, when dealing with advanced model updating of lightweight structures with complex structural dynamics. Laser Doppler Velocimetry, with its scanning variances, is generally accepted as the reference technology in measuring vibration patterns with high spatial de...
Article
Thanks to the progress of optical measurement systems, known to use non-contact transducers (with their own peculiarities, application domains and drawbacks), nowadays addressing complex testing problems, especially direct dynamic measurements and modal analyses on lightweight structural components, is becoming even more common than in the recent p...
Conference Paper
Full-text available
Vision systems are continuously expanding the sensing capabilities of modern vibration testing, while approaching the NVH measurements from quite different technological perspectives and physics. There is astrong need in many design procedures of reliability, precision and physical soundness in the obtainable data from the experiment-based quantiti...
Article
Thanks to the recent advances in digital vision systems, a question might arise about where the full-field optical and contactless methods can bring modern design procedures. An answer lies on the methodologically detailed comparison of the results, processed from different full-field optical techniques, in exploring consistent and high-resolution...
Article
The complete elimination of flaws in complex parts raises the overall costs, especially under stringent safety or service targets, while advanced knowledge might grade the risk of running defected parts with savings. Introducing the novel concept of defect tolerance, this work proposes to exploit experiment-based full-field measurements from optica...
Article
Full-text available
The structural dynamics of a manufactured part or system is often used as a key player in the discrimination of a sound behaviour or of a defected component, which must not go into service. Many NDT approaches exploit different loading systems to enhance the recognition of defects in components. Among the NDT techniques, Shearography, with its opto...
Article
Full-text available
In real life production of dynamically loaded components, we might accept the risk of defects only if we can assess their position by NDT techniques, their effect by proper cumulative damage theory, the dynamic signature of the excitation and the structural dynamics of our structures in service. This work addresses the latter topic by means of expe...
Presentation
Full-text available
The structural dynamics of a manufactured part or system is often used as a key player in the discrimination of a sound behaviour or of a defected component, which must not go into service. Many NDT approaches exploit different loading systems to enhance the recognition of defects in components. Among the NDT techniques, Shearography, with its opto...
Presentation
Full-text available
In real life production of dynamically loaded components, we might accept the risk of defects only if we can assess their position by NDT techniques, their effect by proper cumulative damage theory, the dynamic signature of the excitation and the structural dynamics of our structures in service. This work addresses the latter topic by means of expe...
Article
This paper presents a simulation and experimental study on the measurement with multiple, i.e. more than 2, synchronous cameras of the flexural deflection shape of a beam excited by a transverse force at the fundamental resonance frequency, which gives a good estimate of the first flexural natural mode shape. The first part of the paper presents th...
Conference Paper
This paper presents a simulation and experimental study on the measurement with multiple cameras of the flexural deflection shape of a beam excited by a transverse force at the fundamental resonance frequency, which gives a good estimate of the first flexural natural mode shape. The first part of the study presents the simplified optical model empl...
Article
It is a common practice in industry to model the elasticity in flexible multibody dynamics, when the deformations are small, by means of a linear finite element approach and of a model condensation strategy. Taking into account the flexibility in multibody modelling may require computationally expensive numerical models to be managed. Proper shape...
Conference Paper
Full-text available
Not only the well known and spread horizontal axis machines are present in the wind turbine scenario, but other architectures have found their niche. Among them, the Darrieus solution is known for its relatively compact design and small size, but, even more, for its vertical axis, as well as for the vertical blades distributed on the side of a rota...
Conference Paper
Full-text available
Flexible multibody dynamics is often approached in case of small flexible deformations by means of the finite-element modelling method in component mode synthesis techniques to reduce the size of the computations. In this work, by means of proper shape functions bases, the elastic behaviour of slender beams is approximated in its local axial and tr...
Conference Paper
Full-text available
Gear mesh flexibility is a varying and periodic quantity, which depends on several geometric, motion and material parameters; in NVH and structural analyses of systems with transmission problems this stiffness variability can play an important role on the design targets, such as sound quality and fatigue life estimation. Many times the tooth mesh f...
Poster
Full-text available
Presentation and poster session on the main results of the TEFFMA project (in Italian)
Conference Paper
Full-text available
Towards Experimental Full Field Modal Analysis Risultati del progetto europeo FP7 TEFFMA @ TU-WIEN, Austria Esempio di forme modali ad alta risoluzione spaziale estratte da SLDV, Hi-Speed DIC, Dynamic ESPI I miglioramenti nell'elettronica delle moderne telecamere hanno aumentato l'attenzione sulle tecnologie di misura basate sulle immagini, in part...
Conference Paper
Full-text available
The improvements in the electronics of modern cameras have raised the attention on image based technologies also for the measurement of complex vibration patterns for dynamic analyses in a broad extent beyond Holography. The advent of digital cameras has brought ESPI techniques to a recent success. Besides, the production of hi-speed digital camera...
Conference Paper
Full-text available
Flexible multibody dynamics is often approached in case of small flexible defor- mations by means of the finite-element modelling method or with a component modal base in component mode synthesis techniques. In these approaches the size of the motion equations can be high or general description can be poor. In this paper, instead, a linearly indepe...
Research
Full-text available
Experimental Full Field Modal Analysis from optical measurements in a broad frequency band, results behind the paper: A. Zanarini, "Model updating from full field optical experimental datasets", Proceedings of IFToMM - ICoEV2015 International Conference on Engineering Vibration, 7-10 settembre 2015, Ljubljana (Slovenia), pp.773-782, ID196, EBook -...
Research
Full-text available
Some animated shapes for model updating in the comparison at the base of the paper: A. Zanarini, "Model updating from full field optical experimental datasets", Proceedings of IFToMM - ICoEV2015 International Conference on Engineering Vibration, 7-10 settembre 2015, Ljubljana (Slovenia), pp.773-782, ID196, EBook - Ljubljana: Faculty for Mechanical...
Research
Full-text available
In the framework of the EU-sponsored TEFFMA project (Towards Experimental Full Field Modal Analysis, FP7-PEOPLE-2011-IEF-298543), a comparison was made by means of challenging optical technologies (SLDV, Hi-Speed DIC, Dynamic ESPI) on the same broad band vibration measurement problem of a lightweight plate, with different spatial resolution and qua...
Conference Paper
Full-text available
Advanced optical measurement systems are nowadays at disposal for complex dynamic and modal tests on lightweight structures, each with its own advantages, drawbacks and preferred usage domains, in order to obtain highly spatially defined vibration patterns for many applications in vibration engineering and product development. This work aims at co...
Conference Paper
Full-text available
Full field measurement technologies can not estimate only spatially detailed displacement fields, but can exploit the consistency of the results by means of differentiation operators to obtain rotational degrees of freedom and superficial strain distributions. Both extracted results can be used as advanced benchmarks for numerical models, advanced...
Conference Paper
Full-text available
Experimental techniques based on optical dynamic measurements with high spatial definition proved to be able to model dynamic strain maps on the surface of components by means of corresponding strain frequency response functions. By means of a constitutive model, dynamic stress FRFs can be modelled directly from receptance estimations, avoiding the...
Conference Paper
Full-text available
Are optical measurements and high spatial dense datasets effective in advanced model updating of lightweight structures with complex structural dynamics? The generally accepted reference in measuring vibration patterns with high spatial definition might be the Laser Doppler Velocimetry, with it’s scanning variances, but also with the noise shown in...
Data
Full-text available
Kineto-static analysis of planar mechanisms by means of graphical approaches (in Italian). Theoretical aspects, exhaustive & guided applications on planar mechanisms with friction forces.
Conference Paper
Full-text available
With the evolution of the electronics in hi-speed cameras for digital image correlation, another full field approach is emerging in the vibration engineering community. As for other full field measurement technolo- gies (like SLDV or dynamic ESPI), the displacement patterns that can be extracted have much higher spatial resolution than ordinary mea...
Conference Paper
Full-text available
Different optical techniques are nowadays at disposal for advanced tests on lightweight structures, each with its own advantages, drawbacks and preferred usage domains, in order to obtain highly spatially defined vi- bration patterns for many applications in vibration engineering and product development. This work aims at benchmarking the potential...
Conference Paper
Full-text available
The development of full field measurement technologies can lead nowadays, thanks to the accuracy and consistency of the data fields, to a reliable estimation of dynamic surface strains. Beside the relevant role of advanced benchmarks for the optimisation of numerical models, advanced finite element formulation and fatigue analysis, the experimental...
Conference Paper
Full-text available
Full field measurements, with their high accuracy in spatial definition of displace- ment patterns, are gaining increasing interest within the engineering community. Whereas in general the full field measurements can be more aimed at laboratory testing like traditional Experimental Modal Analysis (EMA), due to their complex equipment and the relati...
Conference Paper
Full-text available
A motorbike running on off-road terrains, braking and transmitting traction forces to uneven road profiles is certainly a time-varying non-linear mechanical system with broad motion and under heavy external conditions, due to the non-linearity in damping, stiffness and inertial properties. A frequency analysis can highlight the variability of the d...
Book
Full-text available
Graphical kineto-static analysis of planar mechanisms: this book is focused on the modelling and solution of problems with increasing level of complexity. It includes the dedicated theory and fully solved exercises. https://bookshop.editrice-esculapio.com/products/zanarini-analisi-cinetostatica-grafica-di-meccanismi-piani
Conference Paper
Full-text available
Frequency analysis is of uttermost importance when dealing with controllability of a dynamic system in changing working domains. This becomes relevant due to the non-linearity in damping, stiffness and inertia properties of mechanisms with broad motion and under heavy external conditions, such as a motorbike running on off-road terrains, braking an...
Conference Paper
Full-text available
Starting from fruitful past experiences on rolling bearing diagnostics, the research activity here presented has aimed since the beginning to investigate the physical phenomena that are at the base of experimental rotor dynamics, when fluid bearings are involved. An appropriate test bench was designed and a prototype assembled. The peculiarities of...
Conference Paper
Full-text available
Frequency Response Functions allow the description of the input/output relationship between physical quantities in a broad frequency domain; they can be obtained from an experimental set-up or from a numerical model. Dynamic modelling of mechanical parts and structures have relied on transfer functions since the early ’60s, having a strong benefit...
Conference Paper
Full-text available
A growing activity of the first author on full-field vibration measurements and promising analyses on dynamic characterisation of components, on dynamic strain & stresses and on cumulative damage maps has drawn the attention of a foreign institution such as Vienna University of Technology up to offer full access to its Schwingungs- und Strukturanal...
Conference Paper
Full-text available
Durability of mechanical components is usually evaluated by means of virtual modelling, supported by accurate tests for validation. Besides, many structural parts easily exhibit high modal density with complex displacement patterns and strain fields, that might be difficult to estimate through tests on real samples. Electronic Speckle Pattern Inter...
Conference Paper
Full-text available
Electronic Speckle Pattern Interferometry (ESPI) technology gives nowadays the opportunity to measure high spatially defined 3D displacements in a wide frequency range by means of optical laser techniques. An experiment-based procedure for fatigue behaviour assessment of mechanical components is proposed in this paper. ESPI technology is described...
Conference Paper
Full-text available
Fatigue life assessment, independently of the modelling approach adopted, requires ever increasing precise measurements. Any estimation procedure has to choose the sensor location, a non-trivial task in presence of dynamic events, which may excite complex superposition of dynamic behaviours, not determinable without dedicated tests. Dynamic ESPI te...
Conference Paper
Full-text available
The intrinsic variability of dynamic properties in spatial systems is faced in this paper by means of a kinematics-based modal approach. An effective analytical-numerical procedure is here presented to mathematically define a local linear model of a spatial mechanism, composed of rigid bodies connected by standard kinematic and lumped elastic const...
Conference Paper
Full-text available
In this paper Electronic Speckle Pattern Interferometry (ESPI) technique is presented for the structural dynamics of mechanical components. Starting from a brief description of its principles, ESPI is shown with its potentials for the inquiry in complex-shaped displacement fields, due to heterogeneous structure or complex vibration patters, in a wi...
Conference Paper
Full-text available
Electronic Speckle Pattern Interferometry (ESPI) technology gives the opportunity nowadays to measure high spatially defined displacement maps in a wide frequency range by means of optical non-contact techniques. Light structures easily exhibit high modal density with complex patterns, where the shapes might be resolved with a fine grid of experime...
Conference Paper
Full-text available
Experimental measurement of the cutting forces in milling processes can be a useful tool to validate standard and non-conventional milling models to be adopted in most industrial applications. As an example, such models can be used to design the machine tool components and fixtures, to choose the technological process parameters and to define proce...
Conference Paper
Full-text available
The assessment of structural damage location in composite honeycomb sandwich panels is here pursued by means of a complete experimental non-destructive approach on a pre-damaged sample. In the experiments proposed full field displacement maps were acquired by means of optical non-contact Electronic Speckle Pattern Interferometry (ESPI) technology [...
Conference Paper
Full-text available
This paper describes vibro-acoustic direct and indirect measurements for road noise NVH predictions from a complete car. Attention is devoted to the dynamic response of the structure and interior pressure field toward tire patch displacement inputs. The direct measurements exploited the Team Corporation CUBE™ high frequency 6 degree-of-freedom (DOF...
Conference Paper
Full-text available
A complete experimental approach is here carried out to obtain the dynamic characterization of an automotive brake disc fixed on its grounded knuckle. The operative deflection shapes (ODS) were measured under harmonic excitation in the 1–23 kHz frequency range. Electronic Speckle Pattern Interferometry (ESPI) [1, 2] technology was exploited to meas...
Conference Paper
Full-text available
Spatial mechanism dynamical characteristics generally depend on the actual kinematical configuration assumed in the working space. Whole system performance assessment can be obtained by the evaluation of the operating workspace from a purely kinematical standpoint, and by evaluating the flexibility properties of such systems in some reference kinem...
Conference Paper
Full-text available
An analytical-experimental approach is followed to obtain the dynamic model of a car vehicle, taking into account the full dynamic contribution due to tires. Linearized and condensed vehicle equations of motion are first introduced. The experimental modal model of a car tire, consisting of limited sets of eigenfrequencies and eigenshapes is then ex...
Thesis
Full-text available
Added note: Part of the Doctorate was spent abroad for the the title of European Doctorate on Sound and Vibration Studies, obtained from the European Commission-EDSVS Network for the research project "Hybrid modeling for road noise prediction" carried out at Katholieke Universiteit Leuven (Belgium) during the post-graduate research Marie Curie Host...
Article
Full-text available
In this paper a hybrid modelling approach is proposed to predict the road noise in a car in the mid frequency range [0-500Hz] using the FRF based substructuring technology. An experimental model of a tire is combined with a FE model of the suspension and a test model of the car body. Different techniques are used to obtain the accurate models requi...
Article
Full-text available
In this paper, a procedure to update finite element models of the connections between parts of an assembled structure is discussed. Starting from an insight of manual updating actions, based on the comparison between frequencies, modal assurance criterion matrices and frequency response functions, an algorithm is proposed in order to extract data f...
Article
Full-text available
A study on the dynamic behaviour of a rotary table transfer machine is discussed in this paper. Part modelling is performed through the application of finite element techniques. Experimental modal analysis is exploited for substructure updating. The assembled model is obtained using constraint equations and boundary conditions. Design modifications...

Questions

Questions (2)

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Projects

Projects (4)
Archived project
The main aim of the project is to create a hybrid model able to predict the road noise transfer inside the car. Different techniques will be used in order to obtain the models required: experimental for the tires, finite elements for the suspensions, experimental for the car body. These three kinds of models will be coupled in CAE environment. Validation of the assembled model will follow, using the transfer functions of a speaker on the pavement and a microphone inside the car. Related research concerns the investigation of the problem of Ride Comfort (low frequency vibration comfort), in order to quest the limits or complementarity of the Multibody method versus the F.E. approach.
Project
In the broad field of mechanics, optical interferometry is a very powerful measurement tool. For years, holography and shearography have provided information on vibration, for strain and stress analysis and for non-destructive testing (e.g. debonded, delaminated and corroded areas). The recent success is due to the signifance advances made in automatic fringe analysis by computer, which made the method more user-friendly. These global techniques are responsive to micro-deformations of surface structures. They allow analysis of large surfaces (square meter and more) at once and without any physical contact, providing useful data for the design of structural components as well as for testing of their integrity during the whole life of the structures. Modal analysis is a very important tool in automotive and aeronautic industries. The study of vibration on dynamically loaded components helps to understand the mechanical behaviour of these components and can be used to reduce acoustic noise and to minimize fatigue loading. The methods usually encountered in vibration analysis are based on the data from local sensors mechanically bonded to the components under study or on vibrometry. Both methods have their specific drawbacks that could be overcome by speckle interferometry, as it provides global information without mechanical contact. Up to now, a system for modal analyis based on speckle interferometry is not available. Based on the success of the project “Pulsed Digital Holography and Shearography”, where a system for the measurement of a dynamic deformation was developed, it is now feasible to realise an integrated and automated system for modal analysis in an industrial environment. The research of the fellow will focus on the the measurement data requirements expected for running an effective experimental vibration analysis (such as Experimental Modal Analysis, Running Modes Analysis, Principal Components Analysis, Transfer Path Analysis, Frequency Response Function Based Substructuring) as it is actually done with traditional transducers. Starting from the training on the Dantec Ettemeyer systems and background theory on Electronic Speckle Pattern Interferometry, the fellow will perform an analysis of proper data type and their signal to noise ratio for displacements, velocities and accelerations; the study will have a parallel contribution from geometry calculation (contouring measurements) to enhance the precision in 3D field, since the spatial distribution of the measurements is basic in the successive modeshape identification procedures. For a different range of experimental and hybrid techniques, as mentioned before, the spectral content of the acquired information is of uttermost importance, so that the research will focus also on the spectra of the measurements to provide the final user the frequency information expected. To fulfill this requirement, that is typical for devices acquiring in the time domain whereas the speckle interferometry works in the spatial domain, high frequency pulsed laser and high acquisition rate CCD cameras will be employed. Spatial Fourier Transforms will also be studied in order to identify the eigenmodes and static modeshapes directly from the displacement measurements and investigate the experimental dualism between frequency and spatial domain measurements, such as pointed out numerically in the Componet Mode Synthesis theory. The developments of this research will have a wide applicability in the mechanical field measurements, varying from automotive to aerospace, to civil engineering, to material behavior analysis, etc. Industrial applica- tions will be investigated to validate the outcomes. Activity held from April 2004 to July 2005
Project
In the last years, the need for high power density and efficiency has become a central concern in all industrial sectors. For this reason, the arrival on the market of new power devices based on wide bandgap (SiC and GaN) semiconductors, with extremely short switching times, has raised a relevant interest. Aerospace industry is one of the main areas which can take advantage from these devices. According to the MEA concept, replacing the aircraft’s hydraulic/mechanical actuators with electrical drives yields an improvement in efficiency and power density, which means a reduction in weight, fuel consumption and noise/pollutants emission. However, some reliability issues may arise in this type of electric drives, as devices with higher voltage gradients have a negative impact on the performace of high voltage insulation systems. As such, there is a need to assess if state-of-the-art insulation materials of machines and power electronic components are suitable for future applications using higher supply voltages and higher switching gradients. The proposed project comprehends the analysis and the experimental assessment of state-of-the-art insulation materials and systems used in aircraft applications.