The existence of a crack in a structure produces changes in modal parameters of it such as natural frequencies, damping, displacement and strain mode shapes. This paper is focused on characterization of crack detection methods using strain mode shapes. To characterize crack detection methods, we changed sensing grids from corner grid to cross grid and geometry of the specimens from rectangular to triangular plate. Rest of conditions was fixed. For crack detection criteria, COMAC, ECOMAC, ADSM and new method have been used and the results are compared with each other. The COMAC, ECOMAC and ADSM showed limited capacity of crack detection on plates but the new method gave good results in 90% of all cases.