Optimal Evaluation of the Rheological Parameters for STF Dampers in Semi-Rigid Joints of Steel Structures Using Response Surface Method

Table 4

ANOVA for damping constant.

Source	Sum of squares	df	Mean square	F value	value
Model	7.091E + 05	20	35454.06	0.5880	0.8899	Significant
A (load frequency)	4618.08	1	4618.08	0.0766	0.7839
B (% of STF with oil)	748.21	1	748.21	0.0124	0.9121
C (initial viscosity)	64429.08	1	64429.08	1.07	0.3098
D (stiffener thickness)	205.11	1	205.11	0.0034	0.9539
E (applied force)	89489.97	1	89489.97	1.48	0.2329
AB	1.242E + 05	1	1.242E + 05	2.06	0.1619
AC	98257.44	1	98257.44	1.63	0.2119
AD	5671.13	1	5671.13	0.0941	0.7613
AE	16128.08	1	16128.08	0.2675	0.6089
BC	4787.31	1	4787.31	0.0794	0.7801
BD	44357.31	1	44357.31	0.7357	0.3981
BE	75991.51	1	75991.51	1.26	0.2708
CD	273.78	1	273.78	0.0045	0.9467
CE	32947.45	1	32947.45	0.5465	0.4657
DE	52164.50	1	52164.50	0.8652	0.3600
A^2	3851.28	1	3851.28	0.0639	0.8023
B^2	19106.44	1	19106.44	0.3169	0.5778
C^2	9405.06	1	9405.06	0.1560	0.6958
D^2	5071.89	1	5071.89	0.0841	0.7739
E^2	81879.64	1	81879.64	1.36	0.2534
Residual	1.748E + 06	29	60291.95
Lack of fit	1.318E + 06	22	59898.97	0.9735	0.5596	Not significant
Pure error	4.307E + 05	7	61527.00
Cor total	2.458E + 06	49