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

Table 13

% of the relative errors on the variance of the critical speeds for different regression orders and correlation functions. Symmetric case with 350 samples.

	Gaussian	Linear	Exponential	Cubic
Zero-order regression
	(138.39; 1.80)	(68.37; 1.98)	(45.39; 1.42)	(122.98; 2.64)
	(14.34; 1.63)	(15.14; 1.87)	(8.59; 1.69)	(16.47; 2.03)
	(17.39; 1.41)	(5.85; 1.37)	(6.37; 1.34)	(6.62; 1.40)
	(20.06; 1.36)	(6.84; 1.37)	(7.01; 1.33)	(12.02; 1.42)
	(0.84; 0.14)	(1.28; 0.16)	(1.13; 0.15)	(2.20; 0.19)
	(0.07; 0.02)	(1.73; 0.09)	(0.65; 0.04)	(4.16; 0.16)
	(0.04; 0.01)	(0.89; 0.04)	(0.64; 0.02)	(2.04; 0.07)
	(0.00; 0.00)	(0.33; 0.02)	(0.11; 0.01)	(0.80; 0.03)
First-order regression
	(49.51; 1.21)	(22.60; 1.19)	(16.09; 1.09)	(33.28; 1.15)
	(14.46; 1.61)	(5.84; 1.63)	(5.39; 1.60)	(6.06; 1.60)
	(11.65; 1.41)	(5.38; 1.39)	(5.89; 1.35)	(9.30; 1.40)
	(10.18; 1.32)	(5.66; 1.30)	(6.25; 1.30)	(5.80; 1.28)
	(0.84; 0.14)	(0.88; 0.15)	(0.87; 0.15)	(1.06; 0.16)
	(0.07; 0.02)	(0.72; 0.03)	(0.60; 0.02)	(0.99; 0.03)
	(0.04; 0.01)	(0.34; 0.01)	(0.27; 0.01)	(0.47; 0.01)
	(0.00; 0.00)	(0.01; 0.00)	(0.01; 0.00)	(0.02; 0.00)
Second-order regression
	(29.53; 3.99)	(5.87; 1.03)	(4.78; 1.02)	(9.83; 1.01)
	(19.95; 1.99)	(4.82; 1.56)	(4.80; 1.57)	(5.13; 1.55)
	(6.99; 1.38)	(5.29; 1.35)	(5.34; 1.33)	(4.79; 1.34)
	(6.30; 1.67)	(5.79; 1.29)	(6.05; 1.29)	(5.98; 1.26)
	(0.84; 0.14)	(0.82; 0.15)	(0.82; 0.15)	(0.81; 0.15)
	(0.07; 0.02)	(0.15; 0.02)	(0.13; 0.02)	(0.26; 0.02)
	(0.04; 0.01)	(0.04; 0.01)	(0.04; 0.01)	(0.04; 0.01)
	(0.00; 0.00)	(0.01; 0.00)	(0.00; 0.00)	(0.01; 0.00)