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

Table 3

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

Actual depth	Actual crack gap	Estimated depth (error factor)	Estimated crack gap (error factor)
7 mm crack (mm)
2.0	1.0	2.23 (11.5%)	0.92 (8%)
	2.0	2.23 (11.5%)	2.21 (10.5%)
	3.0	2.0 (0%)	2.86 (4.6%)
	4.0	1.92 (4%)	3.88 (3%)
10 mm crack (mm)
4.0	1.0	4.02 (0.5%)	1.11 (11%)
	2.0	3.96 (1%)	2.24 (12%)
	3.0	3.85 (3.75%)	2.86 (4.6%)
	4.0	3.79 (5.25%)	3.96 (1%)