Three-point bending fatigue of cracked giant magnetostrictive materials under magnetic fields

This paper investigates the cyclic fatigue behavior in giant magnetostrictive materials with a crack under magnetic fields. Fatigue tests were performed in three-point bending with single-edge precracked-beam specimens, and the number of cycles to failure under sinusoidal mechanical loads and magnetic fields was obtained. A finite element analysis was also carried out, and the energy release rate was calculated. The effect of magnetic fields on the maximum energy release rate versus number of cycles to failure curve was then discussed. In addition, fracture surfaces were examined by scanning electron microscopy and laser microscopy to correlate with fatigue characteristics.