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Digital archive of theses discussed at the University of Pisa


Thesis etd-03262014-180407

Thesis type
Tesi di dottorato di ricerca
Thesis title
Smart materials and vehicle efficiency. Design and experimentation of new devices.
Academic discipline
Course of study
relatore Prof. Forte, Paola
tutor Prof. Frendo, Francesco
  • Design
  • Experimentation
  • Magnetorheological fluids
  • MR
  • Shape memory alloys
  • SMA
  • Vehicle effciciency
Graduation session start date
In this dissertation the activities carried out during the PhD are comprehensively
described. The research mainly focused on the development
of novel smart devices aimed at disengaging auxiliaries in internal combustion
engine vehicles. In particular, the activities dealt with modeling,
design, manufacturing and testing different fail-safe magnetorheological
clutch prototypes, in the framework of a project funded by Regione
Toscana, which involved two departments of the University of Pisa and
Pierburg Pump Technology - Stabilimento di Livorno.
After an extended literature review, several concepts of the clutch
were proposed, which led to the design of the first magnetorheological
prototype. An intensive experimental campaign was conducted, which
involved several prototypes. A particular attention was focused on the
measurement and analysis of the torque transmitted by the clutch in
different operating conditions and new indices were proposed to objectively
analyze the performances of magnetorheological clutches in general. On
the basis of the results of the first experimental phase, the limits of the
first design were analyzed and a novel prototype was developed, which
succeeded in fulfilling all the design specifications.
Further analyses were carried out in order to develop a clutch model
starting from the experimental results. The effect of clutch heating was
considered and a complete model of the clutch based on neural networks
was proposed. The model was capable of taking into account the effect
of the main parameters influencing the torque characteristic and may be
used in a vehicle simulator or in a hardware-in-the-loop bench.
Finally, an additional component to be connected to the clutch, which
made use of shape memory alloys, was developed and tested during the
visiting period at the University of Toledo (OH), USA.