09. Perhitungan Konstruksi Dasar.pptx

8/14/2019 09. Perhitungan Konstruksi Dasar.pptx

1/32

Agustus 2013

Jurusan Teknik Sistem Perkapalan

Fakultas Teknologi Kelautan ITS SurabayaTahun 2013-2014


2/32

Contents :

A. Single Bottom

1. Floor Plates

1.2.1. Floor Plates in the cargo hold area

1.2.3. Floor Plates in the peaks 2. Longitudinal girders 2.2.1. Centre girder

2.2.2. Side girder


3/32

B. Double Bottom

1. General 2. Centre girder 3. Side girder 4. Inner bottom 5. Double bottom tanks 6. Double bottom, transverse framing system

6.1. Plate floors 6.3. Watertight floors 6.4. Bracket floors 6.5. Brackets 6.6. Struts


4/32

7. Double Bottom, Longitudinal Framing System 7.2. Bottom and inner bottom longitudinals 7.3. Plate floors

7.4. Brackets 7.5. Longitudinal girder system

C. Bottom Structure in Machinery Spaces in way ofthe Main Propulsion Plant

1. Single bottom 2. Double bottom 3. Engine seating


5/32

1.2.1 Floor plates in the cargo hold area Floor plates fitted between after peak bulkhead and collision

bulkhead, the section modulus is not to be less than:

5


6/32

The depth of the floor plates is not less than:h = 55 B 45 [mm]hmin = 180 mm

In ship having rise of floor. At 0,1 l from the ends of thelength l where possible, the depth of the floor plate websshall not be less than half the required depth.

Ships having a considerable rise of floor, the depth of the

floor plate webs at the beginning of the turn of bilge isnot less than the depth of frame.

Web thickness is not be less than:

t = h/100 + 3 [mm]

6


7/32

.1 The thickness of the floor plates in the peaks is not to beless than:

The thickness, however, need not be greater than required

by B.6.2.1.critical plate thickness see next slide

7

1.2.3 Floor plates in the peaks


8/32

The thickness, however, need not be greater thenrequired by B.6.2.1 ( the thickness of plate floors) :

tpf = ( tm - 2,0 ) . k [mm] tpf 16,0 mm

tm = thickness of the centre girder according B2.2.2 (the thickness of the centre girder) B2.2.2. The thickness of the centre girder is not to be less then: within 0,7 L amidship:

tm = h/ha [h/100 + 1,0].k [mm], for h 1200 mm tm = h/ha [h/120 + 3,0].k [mm], for h > 1200 mm ha = depth of the centre girder as build [mm] tm =shall not to be less then t according to 7.5 :

t = (5,0 + 0,03L)k [mm], tmin = 6,0 k [mm]


9/32

.2The floor plate

height in the fore

peak above top of

the keel or stemshoe is not to beless then :

h = 0,06 H + 0,7

[m]


10/3210

The stern tube is to be serroundedby the floor plates or, when the

ships shape is too narrow to bestiffened by internal rings. Whereno sole piece is fitted the internalrings may be dispenced with.

.3 The floor plates in theafter peak are to extendover the stern tube (see

also sec.13.C.1.4):


11/32

2. General 2.1.1 All single bottom ships are to have a centre girder. Side girders shall not be installed where the breadth measured on

top of floors does not exceed 6 m.

One side girder when the breadth measured on top of floors doesnot exceed 9 m.

Two side girders when the breadth measured on top of floorsexceed 9 m.

2.1.2 For the spacing of side girders from each other and from thecentre girder in way of bottom strengthening forward seeSection 6, E.1. see next slide

2.1.3 The continuous (centre) and intercostal side girders are to extendas far forward and aft as practicable and stiffened at their upper edge.

11


12/32

1. Arrangement of floors and girders

1.1 For the purpose of arranging floors and girders the

following areas are defined: -forward of x/L = o,7 for L 100 m -forward of x/L = 0,6 + 0,001 L for 100m < L 150 m -forward of x/L = 0,75 for L > 150 m

1.3 In case of tranverse framing, the spacing of side girders isnot to exceed L/250 + 0,9 [m] , up to a maximum of 1,4 m

12


13/32

2.2.1 Centre girder The web thickness tw and the sectional area of the face plate Af within 0,7 L

amidships is not to be less than:

Towards the ends the thickness of the web plate as well as the sectional areaof the top plate may be reduced by 10 %. Lightening holes are to be avoided.

2.2.2 Side girders: The web thickness tw and the sectional area of the face plate Af within 0,7 L

amidships is not to be less than:

Towards the ends, the thickness of the web plate and the sectional area ofthe face plate may be reduced by 10%.

13


14/32

Lightening holes may be fitted in the platefloors. The length of lightening holes may not exceed 0,75 of

the depth of center girder. The depth of holes may not more than 0,5 of the

depth of floor.min 300 mm

The total length of lightening holes may not more

than 0,5 of the length of plate floor from centergirders to the margin plate.

The web of plate floor close to center girder may notless than 0,4 the depth of center girder.

14


15/32

2. Centre girder 2.2.1. The depth of the centre girder is not to be less then h = 350 + 45. B [mm] hmin = 600 mm 2.2.2. The thickness of the centre girder is not to be less then: within 0,7 L amidship: tm = h/ha [h/100 + 1,0].k [mm], for h 1200 mm tm = h/ha [h/120 + 3,0].k [mm], for h > 1200 mm ha = depth of the centre girder as build [mm] tm =shall not to be less then t according to 7.5 t = (5,0 + 0,03L)k [mm], tmin = 6,0 k [mm]

within0,15 L at the ends: te = 0,9 tm,


16/32

3. Side girders

3.2. The thickness of the side girder is not to be less then: t = h / (120.ha ). k [mm] h = depth of the centre girder [mm]

ha = depth of the side girder as build [mm]

ha = need not to be taken less then h to calculate t t = shall not be less then t according 7.5


17/32

4. Inner bottom

4.1. The thickness of the inner bottom plating is not to be less then: t = 1,1. a. p. k + tK [mm]

p = design pressure [kN/m] p is the greater of the following values: p1 = 10 ( T hDB ) p2 = 10. h, where the inner bottom forms a tank boundary p3 = Pi according to Section 4.C.2 (see next slide) h = distance from top of the overflow pipe to inner bottom [m] hDB = double bottom height [m] tK = corrosion additions according to section 3.K

(see next slide)


18/32

Sec.4.C.2. Load on inner bottom

pi = 9,81 G/V. h (1 + av ) [kN/m] G = mass of cargo in the hold [t] V = volume of the hold [m] h = height of the highest point of the cargo

above the inner bottom [m], assuming holdto be completely filled.

av = acceleration factor = F.m, see 4.C.1.1


19/32


20/32

(Penumpu tengah ,menerus)

Plate floor/Solid floor

(wrang pelat)

(Lunas pelat datar)

(Penumpu samping ,terputus)

(Wrang pelat)

Innerbottom frame /reverse frame(Gading alas dalam /gading balik)

Bottom frame(Gading alas )

/Open floor(Wrang terbuka)Keel plate

(Pelat lunas)

Innerbottom plating(pelat alas dalam)

Bottom plating(pelat alas)


21/32

6.2.1 The thickness of the plate floor is not to be less then Tpf = ( tm - 2). k [mm] tm = thickness of centre girder according to 2.2.2. The thickness is not exeed 16,0 mm

The web sectional area is not to be less then Aw = . T. l. e ( 1 2y/l ). k e = spacing of the plate floors [m] l = span between longitudinal bulkheads,if any [m] l = B, if longitudinal bulkheads are not fitted. y = distance between supporting points of the plate

floors,(ship sides, longitudinal bulkheads) and the sectionconsidered [m], not to be greater then 0,4 l.

= 0,5 for spaces which may be empty at full draught,e.g.machinery spaces, store rooms etc.

= 0,3 , elsewhere


22/32

The section modulus of the bottom and innerbottom frame is not to be less then

W = n. c. a. l. p. k [cm]

p = design load, as follows for inner bottom frames

p = pi according to Section 4.C.2

= p1 or p2 according to Section 4.D.1

= 10 ( ThDB) hDB = double bottom height [m]

The greater

value is tobe used


23/32

n = 0,44, if p = p2 = 0,55, if p = pi or p1 = 0,70, if p = pB

c = 0,6 where strut according to 6.6 are providedat l/2, otherwise c = 1,0. l = unsupported span [m] disregarding struts, if any

The bracket, in general, to be of the same thickness as theplate floors. Their breadth is to be 0,75 of the depth of thecentre girder as per 2.2. The bracket are to be flange attheir free edge, where the unsupported span of bottomframes exceed 1,0 m or where the depth of floors exceed

750 mm


24/32

At the side girders,bottom frame and inner bottom

frames are supported by flat bars having the same depthas the inner bottom.

The cross sectional area of the struts as Section 10.C.2 (Pillar scantlings)

The design force is to be taken

P = 0,5. p. a. l [kN] p = load according to 6.4.3

l = unsupported span according to 6.4.3.


25/3225

Plate floor(wrang pelat)

(Pembujur alasdalam)

(Pembujur alas)

Innerbottom plating(pelat alas dalam)

(Pelat lunas)

Plate floor(wrang pelat)

(Penumpu tengah,

menerus)

(Penumpu samping,terputus)

(Bracket)


26/32

7.2 Bottom and inner bottom longitudinals

The section moduli according to section 9.B.3 .1(Framing system)

Sec.9.B.3.1 :

The section modulus Wland shear area Alof

longitudinals is not to be less then:


27/32

See Sec.9 B.2. Definations


28/32


29/32

29Fig. 9.4 End attachment


30/32

Inner bottom longitudinal

Bottom plating

Plate floor,watertightfloor

Bottom longitudinal

Tank top / inner bottom plating

Brackets


31/32


32/32

7.3.4 The scantling of plate floors are to bedetermined according to 6.2 (Plate floors

scantlings in transverse framing system)see slide no.18 etc.

Documents

09. Perhitungan Konstruksi Dasar.pptx