Chain cross-section The input for this model element will generate an Axisymmetric cross-section representing the properties for a chain. Inputs are Nominal diameter Steel grade Construction type: Studless Stud link 1. Cross-section properties Mass coefficient: \(m_{coeff}=m_{air}\) Chain diameter in mm: d Weight in air (dry mass): \(m_{air}=a d^2\) [kg/m] (DNV-OS-E302) Coefficient in calculating chain mass in air a Stud link chain 0.0219 Studless chain 0.02 External cross sectional area: \[A_{ext}=\frac{1}{\rho_{sw}} m_{air} (1-r_{air}^{sub})\\ \rho_{sw}= 1025 kg/m^3\\ r^{sub}_{air}=\frac{m_{sub}}{m_{air}}=0.87\\\] where \(r^{sub}_{air}\) is the ratio between submerged weight to weight in air (dry mass). Reference: Vicinay Offshore Mooring Chain website 2. Stiffness properties The axial stiffness is given as \(EA=c_{EA} \pi d^2\) [kN] (DNV-OS-E302) where cEA Grade R3 Grade R4 Grade R5 Stud link chain 30.7 Studless chain 27 - 0.02d 27.25 - 0.0125d 30 - 0.0165d 3. Capacity properties Tension capacity: \(MBL=c_{MBL} d^2(44 - 0.08d)\) [kN] (DNV-OS-E302) where Grade R3 R3S R4 R4S R5 cMBL 0.0223 0.0249 0.0274 0.0304 0.0320 4. Hydrodynamic force coefficients Load formulation is Morison Input code: Non-dimensional coefficients Quadratic drag coefficient with respect to d \(C_{Qx}\) \(C_{Qy}\) Stud link chain 1.4 2.6 Studless chain 1.15 2.4 Added mass in tangential direction \(C_{Ax}=0.5\) (Bureau Veritas NR 493) Added mass in normal direction \(C_{Ay}=1.0\) (Bureau Veritas NR 493) Linear drag coefficient in tangential direction \(C_{Lx}=0.0\) Linear drag coefficient in normal direction \(C_{Ly}=0.0\) Note that drag coefficients are according to DNV-OS-E301 and \(C_{dt}^{chain}\) quadratic drag coefficient in tangential direction is divided by \(\pi\) when filling CQx field in RIFLEX Axisymmetric cross section (CQx = 1.15/pi = 0.3661) due to RIFLEX’s convention. See also Input Reference The added mass coefficients given in NR493 are based on effective diameter (\(1.8*D_{nominal}\)) and they are updated in RIFLEX Axisymmetric cross section to be used together with the nominal diameter in the calculations. General Cross Section Fibre Rope Cross Section