MECHANICAL BEHAVIOUR OF MAGNETIC SILLY PUTTY: VISCOELASTIC AND MAGNETORHEOLOGICAL PROPERTIES

摘要

In this work the mechanical and viscoelastic properties of the magnetic Silly Putty are investigated. Silly Putty is a non-Newtonian material whose response depends on the rate at which it is deformed. For a rapid deformation it behaves as an elastic solid while over a relatively long time scale stress, the polymer molecules can be untangled and it flows as a fluid. The purpose of this paper is to study the behaviour of this material firstly under a quasi-static compression and shear and secondly under a dynamic shear loading. The Silly Putty under study presents a volume fraction of ferromagnetic particles. Hence, both quasi-static and dynamic stress are coupled with several values of magnetic field in order to assess the influence on the mechanical and viscoelastic properties of magnetic Silly Putty. The approach adopted in this work was based on a Design of Experiment technique so that evaluating the influence of the variables involved and their interactions is possible. The results highlight a strong dependence on the deformation rate while the influence of the magnetic field is weak especially under dynamic shear tests in which the highest deformation are predominant.