Laboratory of Structures and Smart Materials

Scientific Director: Professor Francesco dell’Isola

Activity

 

The Laboratory of Structures and Smart Materials is a research and development hub of the University of Rome “La Sapienza”, located inGiuliano di Roma. This laboratory is actively engaged in the study and prototyping of smart structures in collaboration with the Dipartimento di Ingegneria Strutturale e Geotecnica, Ingegneria Elettronica, Ingegneria Meccanica e Areospaziale and Ingegneria per le Scienze di Base e Applicate and the International Research Center for the Mathematics and Mechanics of Complex Systems of University of L’Aquila.

Since 1997 the research group has addressed the issue of vibration damping of mechanical structures using coupled piezoelectric transducers with electronic systems. In this context, research is oriented to the linear and nonlinear control of structural dynamics.

Lightweight structures such as panels and beams are coupled with a system of piezoelectric transducers interconnected via electronic circuits. Piezoelectric transducers allow bidirectional conversion between mechanical and electrical energy, thus fulfilling the dual and simultaneous role of sensors and actuators. The electronic circuitry permits the regulation and manages the transfer of energy. In order to perform this task it acquires signals from the sensors, processes them and provides power for control actions.

For example a typical application is in the design of soundproofing systems for the passenger compartment of an aircraft or a helicopter. In this case, it is necessary to filter the frequencies of the acoustic band transmitted by the panels, which are subjected to both the pressure associated with the aerodynamic flow and the vibrations due to the engine or to the rotor of the device.

Furthermore, the flutter on panels of the wing or the blades of a rotor is characterized by the instability conditions that occur when the flow speed reaches a critical value. This value can be increased by changing the stiffness of the structure, e.g. by varying the applied voltage to piezoelectric elements bonded on these structural elements.

Another issue of practical interest is the identification of structural damage and the design of smart systems able to self-monitor the evolution of its constitutive parameters.

During 2009 LSMI set as its objective the study of control systems applied to structures characterized by uncertain parameters.

It was used as an opportunity to approach the study of new problems even where the investigation of the structural uncertainties was ignored by the literature and on which it was possible to work in order to study traditional methods and possibly suggest new ones.

Issues that are addressed to this end were as follows:

  1. Uncertainty modeling in inhomogeneous structures with unknown inhomogeneity and stimulated by piezoelectric actuators;
  2. Analysis of metals subjected to the action of external loads and induced structural changes, such as anisotropy and strength of the material.

TThe first step was an important opportunity for interaction with other universities on fundamental founding principles of the Laboratory, providing the opportunity to:

  1. acquire experience with the use of non-deterministic modeling techniques;
  2. develop innovative topics and issues of interest where modeling uncertainty have received little attention.

The second step is the natural extension and evolution of six years work that this Laboratory has carried out with international recognition.

Equipment
  • PSV-400-H4 Scanning Vibrometer, Polytec with velocity range 0 -10 m/s and frequency range 0-80 kHz;
  • Air-cooled LDS low force shaker, with sine force peak 98 N, velocity sine peak 1.78 m/s and frequency range 5 – 9000 Hz;
  • Miniature Impact HammerBrüel&Kjaer, with sensitivity 22.7 mV/N;
  • Force transducer IEPE Brüel&Kjaer;
  • Accelerometers Brüel&Kjaer, with internal electronics CCLD, ICP-compatible;
  • Microphones and preamplifiers Brüel&Kjaer;
  • Vibration Isolation Table used to isolate vibration from sensitive lab equipment.
  • 2 iMAC 21,5”, 3,06 Ghz Intel Core 2Duo.
  • 1 PC desktop ASUS CG8580-IT0020 Tytan (Core i7 3770k Processor, 4,6 GHz, RAM 16GB DDR3, 1600MHz).
  • 13 PC with Operative System Window.

Publications
  • Shen, J. Qiu, H. Ji, K. Zhu, M. Balsi, I. Giorgio and F. dell’Isola, “A low-power circuit for piezoelectric vibration control by synchronized switching on voltage source”, Sensors and Actuators A: Physical, vol. 161 (1-2), 2010, pp. 245-255. Download Pdf
  • Rosi, J. Pouget and F. dell’Isola, “Control of sound radiation and transmission by a piezoelectric plate with an optimized resistive electrode”, European Journal of Mechanics, A/Solids, vol. 29 (5), 2010, pp. 859-870. Download Pdf
  • Giorgio, A. Culla, D. Del Vescovo, “Multimode vibration control using several piezoelectric transducers shunted with a multi-terminal network”, Archive of Applied Mechanics, 2009, vol. 79, pp. 859–879.
  • Del Vescovo, A. Fregolent, “Theoretical and experimental dynamic analysis aimed at the improvement of an acoustic method for fresco detachment diagnosis”, Mechanical Systems and Signal Processing, vol. 23 (7), 2009, pp. 2312-2319.
  • Maurini, J. Pouget and F. dell’Isola “Poutres composites piézoélectriques: modélisation des effets 3D, validations numériques et expérimentales”, 8e Colloque National en Calculus des Structures21-25 Mai 2007, Giens (Var). Download Pdf
  • Maurini, J. Pouget, and F. dell’Isola, “Extension of the Euler Bernoulli model of piezoelectric laminates to include 3D effects via a mixed approach”, Computers and Structures, vol. 84 (22-23), 2006, pp. 1438-1458. Download Pdf
  • Maurini, J. Pouget and F. dell’Isola, “Corrections to the constitutive equations of piezoelectric laminated beams through a mixed variational approach”, II ECCOMAS Thematic Conference on Smart Structures and Material, Lisbon, Portugal, July 18 – 21, 2005Download Pdf
  • dell’Isola, F. Vestroni, and S. Vidoli, “Structural-damage detection by distributed piezoelectric transducers and tuned electric circuits”, Research in Nondestructive Evaluation, vol. 16, 2005, pp. 101-118. Download Pdf
  • Porfiri, F. dell’Isola, and E. Santini, “Modeling and design of passive electric networks interconnecting piezoelectric transducers for distributed vibration control”, International Journal of Applied Electromagnetics and Mechanics, vol. 21 (2), 2005, pp. 69-87. Download Pdf
  • Batra, F. dell’Isola, S. Vidoli, and D. Vigilante, “Multimode vibration suppression with passive two-terminal distributed network incorporating piezoceramic transducers”, International Journal of Solids and Structures, vol. 42 (11-12), 2005, pp. 3115-3132. Download Pdf
  • Alessandroni, U. Andreaus, F. dell’Isola, and M. Porfiri, “A passive electric controller for multimodal vibrations of thin plates”, Computers and Structures, vol. 83 (15-16), 2005, p. 1236–1250.Download Pdf
  • Del Vescovo, A. Fregolent, “Assessment of fresco detachments through a non invasive acoustic method”, Journal of Sound Vibration, 2005, vol. 284 (3-5), 1015-1031.
  • Maurini, J. Pouget, F. dell’Isola, “On a model of piezoelectric beam including interaction between different layers”,  XXI International Congress of Theoretical and Applied Mechanics, 15-21 August 2004, Warsaw Poland
  • Maurini, J. Pouget, F. dell’Isola, “Beam models of piezoelectric laminates”, 7th International Conference on Computational Structures Technology, Lisbon, Portugal 7-9 September 2004
  • Porfiri, C. Maurini, F. dell’Isola, J. Pouget, “Different network topologies for distributed electric damping of beam vibrations”, Proceeding of the XXI International Congress of Theoretical and Applied Mechanics, 15-21 August 2004, Warsaw Poland
  • Maurini, F. dell’Isola, and D. Del Vescovo, “Comparison of piezoelectronic networks acting as distributed vibration absorbers”, Mechanical Systems and Signal Processing, vol. 18 (5), 2004, p. 1243–1271. Download Pdf
  • Maurini, J. Pouget, and F. dell’Isola, “On a model of layered piezoelectric beams including transverse stress effect”,  International journal of solids and structures, vol. 41 (16-17), 2004, p. 4473–4502. Download Pdf
  • Maurini, F. dell’Isola and J. Pouget, “On models of layered piezoelectric beams for passive vibration control”, Journal de Physique IV (Proceedings), vol. 115, 2004, p. 307–316. Download Pdf
  • dell’Isola, C. Maurini, and M. Porfiri, “Passive damping of beam vibrations through distributed electric networks and piezoelectric transducers: Prototype design and experimental validation”, Smart Materials and Structures, vol. 13 (2), 2004, pp. 299-308. Download Pdf
  • Porfiri, F. dell’Isola, and F. M. Frattale Mascioli, “Circuit analog of a beam and its application to multimodal vibration damping, using piezoelectric transducers”, International Journal of Circuit Theory and Applications, vol. 32 (4), 2004, pp. 167-198. Download Pdf
  • Alessandroni, U. Andreaus, F. dell’Isola, and M. Porfiri, “Piezo-ElectroMechanical (PEM) Kirchhoff–Love plates”, European Journal of Mechanics/A Solids, vol. 23 (4), 2004, p. 689–702.Download Pdf
  • Andreaus, F. dell’Isola, and M. Porfiri, “Piezoelectric Passive Distributed Controllers for Beam Flexural Vibrations”, Journal of Vibration and Control, vol. 10 (5), 2004, p. 625. Download Pdf
  • Porfiri and F. dell’Isola, “Multimodal beam vibration damping exploiting PZT transducers and passive distributed circuits”, Journal de Physique IV France, vol. 115 (1), 2004, p. 323–330.Download Pdf
  • Vestroni, F. dell’Isola, S. Vidoli, M.N. Cerri, “Structural health monitoring based on dynamic measurements: A standard and a novel approach”, System-Based Vision for Strategic and Creative Design, Vol. 1-3, 2003, pp. 2023-2028
  • Del Vescovo, A. Fregolent, “Sviluppo di un metodo acustico-strutturale per la diagnosi dei distacchi degli affreschi basato sulla dinamica strutturale”, XVI Congresso Nazionale AIMETA, Ferrara, Italia, 2003.
  • dell’Isola and D. Del Vescovo, C. Maurini, M. Porfiri, “Passive electric damping of structural vibrations through distributed piezoelectric coupling: critical analysis”, International Symposium on Applied Electromagnetics and Mechanics, Versailles, France: 2003. Download Pdf
  • dell’Isola, D. Del Vescovo, and C. Maurini, “Distributed electric absorbers of beam vibrations”, SPIE proceedings series, W.K. Agnes G.S., San Diego, CA: SPIE, 2003, p. 230–241. Download Pdf
  • dell’Isola, E.G. Henneke, and M. Porfiri, “Piezoelectromechanical structures: A survey of basic concepts and methodologies”, Proceedings of SPIE – The International Society for Optical Engineering, San Diego, CA: 2003, pp. 574-582. Download Pdf
  • dell’Isola, E.G. Henneke, and M. Porfiri, “Piezoelectromechanical structures: New trends towards the multimodal passive vibration control”, Proceedings of SPIE – The International Society for Optical Engineering, W.K. Agnes G.S., San Diego, CA: 2003, pp. 392-402. Download Pdf
  • dell’Isola, E. Santini, and D. Vigilante, “Purely electrical damping of vibrations in arbitrary PEM plates: A mixed non-conforming FEM-Runge-Kutta time evolution analysis”, Archive of Applied Mechanics, vol. 73 (1-2), 2003, pp. 26-48. Download Pdf
  • dell’Isola, M. Porfiri, and S. Vidoli, “Piezo-electromechanical (PEM) structures: Passive vibration control using distributed piezoelectric transducers”, Comptes Rendus – Mecanique, vol. 331 (1), 2003, pp. 69-76.Download Pdf
  • [U. Andreaus, F. dell’Isola, and M. Porfiri, “Multimodal vibration control by using piezoelectric transducers and passive circuits”, Symposium on Electro-Magneto-Mechanics, 2003, pp. 307-317.Download Pdf
  • Alessandroni, U. Andreaus, and F. dell’Isola, “A novel passive electric network analog to Kirchhoff-Love plate designed to efficiently damp forced vibrations by distributed piezoelectric transducers”, Proceedings of SPIE – The International Society for Optical Engineering, W.K. Agnes G.S., San Diego, CA: 2003, pp. 380-391.
  • Andreaus, F. dell’Isola, and M. Porfiri, “Piezoelectric passive distributed controllers for beam  flexural vibrations”, 14th U.S. National Congress of Applied Mechanics, Blacksburg, VA: 2002.Download Pdf
  • Alessandroni, F. dell’Isola, and M. Porfiri, “A revival of electric analogs for vibrating mechanical systems aimed to their efficient control by PZT actuators”, International Journal of Solids and Structures, vol. 39 (20), 2002, pp. 5295-5324. Download Pdf
  • dell’Isola, E.G. Henneke, and M. Porfiri, “Synthesis of electrical networks interconnecting PZT actuators to damp mechanical vibrations “, International Journal of Applied Electromagnetics and Mechanics, vol. 14 (1-4), 2002, pp. 417-424. Download Pdf
  • Alessandroni, F. dell’Isola, and F. Frezza, “Optimal piezo-electro-mechanical coupling to control plate vibrations “, International Journal of Applied Electromagnetics and Mechanics, vol. 13 (1-4), 2002, pp. 113-120. Download Pdf
  • Vidoli and F. dell’Isola, “Continously distributed control of plates by electric networks with PZT actuators”, Conference in honour of K. Hutter in occasion of his 60th birthday, 2001, pp. 92-110. Download Pdf
  • Vidoli and F. dell’Isola, “Vibration control in plates by uniformly distributed PZT actuators interconnected via electric networks “, European Journal of Mechanics, A/Solids, vol. 20, 2001, pp. 435-456. Download Pdf
  • dell’Isola, E.G. Henneke, and M. Porfiri, “Synthesis of electrical networks interconnecting PZT actuators to damp mechanical vibrations “, International Symposium on Applied Electromagnetics and Mechanics in honor of Professor K.Miya, Tokyo: 2000. Download Pdf
  • Vidoli and F. dell’Isola, “Modal coupling in one-dimensional electromechanical structured continua “, Acta Mechanica, vol. 141 (1-2), 2000, pp. 37-50. Download Pdf