Effect of the Loading Rate on the Brittle Fracture of Terfenol-D Specimens in Magnetic Field: Strain Energy Density Approach

The aim of the present study is to characterize the fracture behavior of the giant magnetostrictive Terfenol-D alloy, both experimentally and numerically. Three-point bending tests have been carried out on single-edge precracked specimens, and fracture loads have been measured at different loading rates, in the presence or absence of a magnetic field. In recent years, it has been shown that the strain energy density (SED), averaged in a finite control volume, can successfully predict brittle failures of cracked, U- and V-notched specimens made of several materials. By performing coupled-field finite element analyses, the effects of the magnetic field and he loading rate on Terfenol-D failures have been analyzed, and the capability of SED criterion to capture these effects has been discussed. A relationship between the SED control volume size and the loading rate has been proposed, and failures have been quite accurately predicted in terms of the averaged SED.