VIV Fracture Investigation into 3D Marine Riser with a Circumferential Outside Surface Crack

Table 2

Properties and size parameters of X65 material for pipeline steel.

Parameter	Value	Parameter	Value
Outside diameter (m)	0.5588	Flow stress (MPa)	526
Thickness (m)	0.00127	Crack semiangle	0.785
Outside flow velocity (m/s)	0.5, 1.0, 1.5, 2.0	Inside fluid density (kg/m^3)	1200
Structural damping ratio (%)	0.3	Pipe material density (kg/m^3)	7900
Yield strength of base metal (MPa)	478	Yield strength of welding seam (MPa)	486
Tensile strength of base metal (MPa)	572	Tensile strength of welding seam (MPa)	587
Sea water density (kg/m^3)	1025	Additional mass coefficient	1.0
Inside flow velocity (m/s)	0,10,20,40	Crack depth (mm)	0.002
Poisson ratio	0.3	Crack length (mm)	0.01
Young’s modulus (GPa)	207	Strain index	4.33
Riser length (m)	300, 400, 500, 600	Strain constant	4.06
Coefficient of top tension	1.2, 1.3, 1.4, 1.5	Internal pressure (MPa)	10