Specification of dynamic amplification parameters (Input Table)

Data description/conditions:

DAMPING:

Damping factor for vibration of pipeline span(s)

≥ 0.

[Default: 0.]

(The damping factor for steel structures in water is about 0.02)

SECTSUP:

Section support factor

> 0.

[Default: 15.4]

(This factor, depending on the mode of vibration of the span, is 9.87 for a 'pin-pin' span, 15.4 for a 'clamp-pin' span and 22.0 for a 'clamp-clamp' span. For free pipeline spans on the sea bed a 'clamp-pin' assumption is reasonable, for risers it is usual to assume 'pip-pin' restraints.)

ADDMASS:

Coefficient of added mass per unit length of pipe

≥ 0.

[Default: 0.7]

(The added mass is determined by multiplying this coefficient by the cross-sectional area of the pipe and by the mass density of the (sea) water.)

FREQFAC:

Factor for angular frequency of wave as forcing function

≥ 0. / Undefined

[Default: 1.]

(The angular frequency of the wave is multiplied by this factor. If UNDEFINED, no multiplication occurs. In general this factor is not applied, but it may be used to take into account, for instance, the influence of vortex shedding.)

H410171, last changed: 2007-07-30

See also: