Section 3 Analysis of Overall Strength

301. Loading conditions

Analysis of overall strength is to be performed for the static loading and combined loading speci- fied in the following (1) and (2) in the respective modes of operation specified in Ch 1, 107.

(1) The static loading is a condition in which the unit is afloat or resting on the sea bed in calm sea and is loaded with static loads only such as loads taken in operating condition, dead load

of the unit, etc. which affect the overall strength.

(2) The combined loading is a condition in which the unit is loaded with combined loads of the static loads specified in (1), and dynamic loads such as wind loads, wave loads, etc. which af- fect the overall strength and loads induced by the accelerative motion of the unit due to these loads and heeling.

302. Allowable stresses

Allowable stresses for static loading and combined loading specified in values in Table 4.4 according to the kind of stress.

301. are not to exceed the

Ch 4 Design Condition Ch 4

Table 4.4 Allowable Stresses for Static Loading and Combined Loading

303. Combined compressive stress

In addition to 302., when structural members are subjected to axial compression or combined axial compression and bending, the extreme fibre stresses shall comply with the following requirement:

ᾚᾍ ᾚᾎ

Ñ Ü

Ü

≤ ÌǾL

Âᾍ ᾎ

ᾚᾍ :

ᾚᾎ :

Âᾎ :

Âᾍ :

Calculated compressive stress due to axial force(NÕmm Ī). Calculated compressive stress due to bending (NÕmm Ī).

Allowable compressive stress due to bending prescribed in Table 4.4 (NÕmm Ī).

Allowable axial compressive stress obtained from the following formula, but is not to exceed

ᾎ

 (NÕmm Ī)

Âᾍ Ņ g× ſſᾏᾮØᾝ ×NÌŇLǾÌĮ×₤Õ₤LŃ ...................... ₤ P ₤L Ņ g× ſſᾏᾮØᾙ × LǾKK ....................................... ₤≥ ₤L

₤ Ņ ᾟᾨÕᾮ

←

₤L Ņ Ρ̓ÜĪſk Ī¢Õſſ

Ī

ſſ← : As specified in 302. (NÕmm ).

ſſᾏᾮØᾝ

: Inelastic column critical buckling stress (NÕmm Ī).

ſſᾏᾮØᾙ : Elastic column critical buckling stress (NÕmm Ī).

g = 0.6 for static loading

= 0.8 for combined loading

ᾟᾨ = effective unsupported length

ᾮ = governing radius of gyration associated with ᾟᾨ

¢ = modulus of elasticity of the material

Ch 4 Design Condition Ch 4