Kriging Metamodeling in Rotordynamics: Application for Predicting Critical Speeds and Vibrations of a Flexible Rotor

Table 6

% of the relative errors on the variance of the critical speeds for different regression orders and correlation functions. Nonsymmetric case with 600 samples.

	Gaussian	Linear	Exponential	Cubic
Zero-order regression
	(151.85; 1.18)	(76.12; 1.66)	(58.14; 0.92)	(166.04; 2.84)
	(48.74; 0.78)	(21.74; 0.67)	(12.19; 0.39)	(77.41; 0.72)
	(10.58; 0.19)	(11.05; 0.33)	(11.89; 0.22)	(7.44; 0.17)
	(12.40; 0.23)	(7.52; 0.41)	(8.02; 0.27)	(6.32; 0.21)
	(0.00; 0.00)	(0.67; 0.02)	(0.29; 0.01)	(1.29; 0.04)
	(0.00; 0.00)	(2.29; 0.07)	(0.78; 0.02)	(5.00; 0.14)
	(0.00; 0.00)	(1.01; 0.03)	(0.69; 0.01)	(2.27; 0.05)
	(0.00; 0.00)	(0.49; 0.01)	(0.16; 0.00)	(1.11; 0.03)
First-order regression
	(72.82; 0.72)	(46.36; 0.86)	(46.19; 0.55)	(61.98; 1.10)
	(39.81; 5.32)	(13.20; 0.52)	(18.12; 0.41)	(12.17; 0.30)
	(8.74; 0.20)	(11.41; 0.33)	(12.06; 0.23)	(7.91; 0.17)
	(10.79; 0.18)	(9.42; 0.40)	(9.06; 0.26)	(9.33; 0.17)
	(0.00; 0.00)	(0.72; 0.01)	(0.60; 0.01)	(1.23; 0.02)
	(0.00; 0.00)	(0.78; 0.01)	(0.68; 0.01)	(1.31; 0.01)
	(0.00; 0.00)	(0.34; 0.01)	(0.25; 0.00)	(0.60; 0.01)
	(0.00; 0.00)	(0.02; 0.00)	(0.01; 0.00)	(0.03; 0.00)
Second-order regression
	(15.47; 0.29)	(35.98; 0.50)	(39.75; 0.38)	(27.97; 0.33)
	(148.91; 4.25)	(12.84; 0.42)	(16.13; 0.37)	(16.10; 0.25)
	(6.95; 0.15)	(11.16; 0.32)	(11.05; 0.21)	(8.06; 0.13)
	(7.37; 0.15)	(7.06; 0.31)	(7.70; 0.23)	(6.55; 0.13)
	(0.00; 0.00)	(0.19; 0.01)	(0.16; 0.00)	(0.33; 0.01)
	(0.00; 0.00)	(0.08; 0.00)	(0.06; 0.00)	(0.13; 0.00)
	(0.00; 0.00)	(0.03; 0.00)	(0.03; 0.00)	(0.05; 0.00)
	(0.00; 0.00)	(0.00; 0.00)	(0.00; 0.00)	(0.01; 0.00)