Table 2.

Statistical details derived from mean crack length and substrate density plots of Fig. 6, at frequencies 1, 10 and 50 Hz. A and D are the constants from the curve fits. R², the squared correlation coefficient indicates the extent of the data and regression line fit. A P-value less than 0.05 confirms statistically significant data, as displayed at 10 Hz of loading frequency

Frequency (Hz)	Total crack length linear fit details
	A	D	R2	P
1	(−)2.652	3.454	0.485	0.304
10	(+)13.077	2.124	0.909	0.047
50	(−)2.999	5.612	0.524	0.276