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La Dra. Ekaterina Pavlovskaia de la Universidad de Aberdeen, Escocia,

impartirá un seminario el martes 19 de octubre de 2010,  a las  17,00 horas en el Seminario del Dpto. de Electrónica y Electromagnetismo, (planta 3ª de la Facultad de Física) sobre el tema

“Dinámica nolineal de un oscilador pseudoelástico discontinuo”


En esta charla se presentará la investigación tanto teórica como experimental del movimiento de un oscilador de impacto, hecho de aleación con memoría de forma, con restricción cinemática del movimiento de uno de sus lados.

La charla será en inglés.

In this talk nonlinear dynamics of impact oscillator with one sided motion constraint made from a shape memory alloy (SMA) will be discussed [1]. The thermo-mechanical description of the SMA element follows the formulation proposed by Bernardini et. al. [2,3]. The thermo-mechanical coupling terms included in the energy balance equation allow to undertake the non-isothermal analysis. The performed numerical investigations suggest that the system can exhibit complex
dynamic responses, which if appropriately controlled can be used for vibration reduction. A comparison with an equivalent elastic oscillator is made and it is found out that the low amplitude regimes are not affected by the SMA element. On contrary, for the large amplitude responses, a significant vibration reduction is achieved due to the phase transformation hysteresis loop. Various bifurcation scenarios are constructed and the influence of the SMA element is
discussed. The results of the experimental study will be also shown and comparison between them and numerical predictions will be demonstrated.

[1] Sitnikova, E., Pavlovskaia, E.E. and Wiercigroch, M. Dynamics of an impact oscillator with SMA constraint, European Physical Journal – Special Topics, 165(1), 229 – 238, 2008.
[2] Bernardini, D., Pence, T. Models for one-variant shape memory materials based on dissipation functions, International Journal of Non-Linear Mechanics, 37, 1299 – 1317, 2002.
[3] Bernardini, D., Rega, G. Thermomechanical modelling, nonlinear dynamics and chaos in shape memory oscillators, Mathematical and Computer Modelling of Dynamical Systems, 11(3), 291 – 314, 2005.

Fuente: Decanato de la Facultad de Física (USE)