High Sensitive Methods for Health Monitoring of Compressor Blades and Fatigue Detection

Table 4

Blade with 11 mm length damage (starting from TE) placed 20 mm from lock [23, 25].

Blade	Frequency change (Hz)
	1st mode	2nd mode	3rd mode
Cracked	−12	+7	−27
Notched (no friction)	−13	−5	−80
Difference (%)	−0.28	−0.86	−2.73