Optimization Design of a Riser-Drill String Coupling System Based on CAE Techniques

Table 2

Effect correlations between the input and output variables.

Output	Input
	Riser diameter	Riser thickness	Top drift	Hanging load	Top tension	Stiffness of lower joint	Stiffness of upper joint
Maximal Mises stress	0.06	−0.12	0.05	0.95	−0.14	0.03	0.04
Maximal deflection	−0.18	−0.09	0.79	−0.26	−0.41	0.01	−0.05
Maximal angle of upper joint	−0.65	0.01	−0.17	−0.34	−0.52	−0.01	−0.17
Maximal angle of lower joint	0.04	0.02	−0.62	0.41	0.55	0.24	0.06