MICROFATIGUE DAMAGE INDUCED BY MAGNETIC FIELD IN PARTICLE FILLED POLYPROPYLENE

O. A. LAMBRI; D. GARGICEVICH; F. G. BONIFACICH; W. RIEHEMANN; M. ANHALT; B. WEIDENFELLER

Foz de Iguazú

Congreso; XV ERIAC - Décimo Quinto Encuentro Regional Ibero-americano del CIGRÉ; 2013

CIGRÉ - ITAUIPU Binacional

The behaviour of damping and dynamic shear modulus has been studied in polypropylene charged with either different volume fraction or size of magnetite particles, as a function of the applied magnetic field at 318 K. It has been found that, an increase of the alternating (AC) magnetic field oscillating with 50 Hz, leads to an increase of the damping. In addition, during the subsequently decreasing alternating magnetic field, the damping decreases, but a hysteretic behaviour appeared. Subsequent magnetic treatment cycles, lead to successively decreasing damping. In contrast, during the increase of a direct (DC) magnetic field, the damping decreases and the elastic modulus increases. The physical mechanisms sontrolling the behaviour of damping and elastic modulus are discussed.