Dynamic Visualization of Crack Tip Stress Field and Propagation Using the Mechano-Luminescence in SrAl2O4: (Eu,Dy,Nd)
The present investigation aimed at visualizing the propagating crack in a mechano-luminescence (ML) material, which enabled us to measure instantaneous R-curves and observe directly the bridging (shielding) stress in the fast-propagating crack system. The well-known ML compound, SrAl2O4:Eu,Dy,Nd, was adopted as a testing material. The crack initiation and growth from the mechanically machined sharp notch tip in the disc shaped compact tension (CT) specimen at a relatively fast loading rate were found to be associated with the extent of light emission around the crack. The in-situ measurement of crack length and applied load for 0.3 sec yielded an instantaneous R-curve at the conventional crack propagation speed.
Z.Y. Zhong, H. Saka, T.H. Kim, E.A. Holm, Y.F. Han and X.S. Xie
J. S. Kim et al., "Dynamic Visualization of Crack Tip Stress Field and Propagation Using the Mechano-Luminescence in SrAl2O4: (Eu,Dy,Nd)", Materials Science Forum, Vols. 475-479, pp. 1121-1124, 2005