The objective of the PyDAMP project is to develop a hybrid mechanical suspension to reduce the vibrations transmission on a wide frequency band. The undesired vibrations are generated by small electric motors (few kilograms). The concept of suspension is inspired by a Class IV flextensionnel transducer [1-3]. Flextensional transducers are a class of mechanical amplifiers composed of an active part, usually piezoelectric (bars, discs, rings), or magnetostrictive, and a shell that radiates in the surrounding fluid [4–6]. The suspension with piezoelectric pillar is developped by PYTHEAS Technology. A finite element study has been achieved to ensure the validity of the concept in terms of maximum admissible Von Mises stress, maximum displacement and modes shapes. An electromechanical model of the piezoelectrical suspension has been developed. Mechanical elements are converted in electrical components and an equivalent electrical circuit can be found. The electromechanical coupling of the transducer allows the introduction of mechanical damping and electric damping with different shunts based on resistor and negative capacitance [7, 8]. The simulation and the shunt optimisation are facilitated with only one physic, taking into account the whole dynamic behaviour of the piezoeletrical suspension.The piezoelectrical suspension is compared to a conventional viscoelastic suspension in terms of performances in the audible frequency range and validated using experimental tests.

1 : J. Butler and C. Sherman, Transducers and arrays for underwater sound, Springer, 2016.

2 : D. Jones and N. Abboud, “Performance analysis of a low-frequency barrel-stave flextensional projector,” in Proceeding of ONR Transducer Materials and Transducers Workshop, pp. 1–4, 1996.

3 : N. Hagood, J. Aldrich, and A. V. Flotow, Design of passive piezoelectric damping for space structures, National Aeronautics and Space Administration, Langley Research Center, 1994.

4 : B. Damiri, Mod`ele analytique pour l'analyse du transducteur flextensionnel de classe IV dans l'air. PhD thesis, Lille 1, 1996.

5 : G. Brigham and L. Royster, “Present status in the design of flextensional underwater acoustic transducers,” The Journal of the Acoustical Society of America 46(1A), pp. 92–92, 1969.

6 : L. Royster, “Predicting the effective dynamic coupling coefficient of the flextensional transducer (preliminary design considerations),” The Journal of the Acoustical Society of America 38(5), pp. 879–880, 1965.

7 : A. Larky, “Negative-impedance converters,” IRE Transactions on Circuit Theory 4(3), pp. 124–131, 1957.

8 : B. De Marneffe and A. Preumont, “Vibration damping with negative capacitance shunts : theory and experiment,”Smart Materials and Structures 17(3), p. 035015, 2008.