A Study on Depth Sizing for Surface Cracks in KTX Brake Disc Using Rayleigh Wave

Table 4

Inspection results for V-double type crack (mm).

Actual depth	Actual crack gap	Estimated depth (error factor)	Estimated crack gap (error factor)
7 mm crack
2.0	1.0	2.25 (12.5%)	1.1 (10%)
	2.0	2.24 (12%)	2.0 (0%)
	3.0	2.22 (11%)	3.2 (6.67%)
10 mm crack (mm)
4.0	1.0	3.8 (5%)	0.9 (10%)
	2.0	3.77 (5.7%)	1.89 (11%)
	3.0	3.98 (0.5%)	3.1 (10%)