Effects of Soft Spring on S/S Response

(1)

TECHNISCHE UNWERSrrErr

Scheapahydrmehin1 ca

Archief

Mekeiweg 2, 2628 cD Delft

Tel: Ol5-2786873/Fax:2781836

23rd May, 1992

ITTC OEC Comparative Study

Effects of Soft Spring on S/S Response

Mitsubishi' Heavy industries, Ltd

K. Ikeganìi 1. Model Test Arrangement i

2. Co-ordinate System 2

3. Motions of Center of Gravity 3-8

4. Motions of Point A 9--'12

5. Accelerations of Point B 13--16

6. Relative Motions of Point C 17--18

7. Relative Motions of Point D 19-20

(2)

Relative wave height probe

7 r

6 component motion measuring apparatus

Dynamo rail 3 component dynamometer Modél Test Arrangement Soft spring Accelerometer

Relative wave height probe

Wave height probe

//

Wave Soft spring 'Surge stiffness : 0.01kg/mm (33ton/m) Sway stiffness. : 0.OÏkg/mth (33ton/m) Yaw stiffness : 5.44kgrn/rad (59. 800tonm/rad)

(3)

Co-ord i nate System

Wave

Ca cos (tut+kXcosfl+kYsini3)

Response

(4)

3 2.5 1.5 .5 2.5 1.5 0

First Ordèr Resonses, C.G.

; MHI-JPN

Sur-ge Heading ; 0 deg.

Tw (seo)

D Ca i (MÒORED) + Ca i. (FREE) O ME SURED

F i rst Order Responses, C. G.

_{; MHI-JPN}

Surge Heading : 30 deg.

10

I

--

j -

i----Ç

20 . 30

Tw (seo)

D Cal (MOORED)

+

. Ca i (FREE) O MEISUREI)

.30

-- I I

(5)

First Ordr Responses., C.G. ; MHI-JÇPPN

Swasj Heading 30 deg.

Tw (seo)

Ö Ca

i

(MOOR8)) + Ca i (FREE)

O MEÍSURED

First Order Responses, C.G.

_{; MHI-JPN}

Swai Heading : 90 deg.

T'. (sec)

(6)

2.5

2

0.5

First Order Responses, C.(31 _;

MHI-JPN

Heave Head i n : 0 deg.

1.5- ...:...

I

0 10 20

Tw (sec)

D Ca i (MOORED) + Ca I (FREE) ' MES1JRED

First Order Responses, C.G1

; MHI-JPN

Heave Heading ; 30 deg.

Tw (sec)

Ö Ca i (MOORED) + Ca i (FREE) O MES1JRED

(7)

2.5 -

21.. 5

-

10.5

-1.8 1.6 -1.4 1.2 1

0.8

-0.6 0.4 0.2 0

; MHI-JPN

Heave Head ¡ ng : 90 deg.

6

First Order Respönses:, C.G.

; MHI-JPN

Roll Head i ng : 30 .de9.

20 30

Tw (sec)

Ö Cal(MOORED) ± Cal(FREE).

OMEISURED

10 20 30

Tw (sec)

(8)

2 1.8 1.6 1.4 1. .2 i 0.8 0.6 0.4 0.2 O

_{; MHI-JPN}

Roil Heading : 90 deg.

Tw (seo)

D Ca i (MOORED) + Ca I (FREE) ° MEÇSURED

First OrderResponses, C.G.

; MHI-JPN

Pitch Heading : 0 deg.

'f

...

10

1w (seò)

D _{Ca i (MOORED)} _{+ Ca I (FREE)} _O _ME8LJRED

20 30

4... 7

(9)

2.5

.5

F i rst Ordér Responses, C. G. ; 11H I-JPN

Pitch Heading.: 3 deg.

Tw (sec)

D Ca i (MOORED) + Ca i (FREE)

Q MESURED

First Order Responses, C.G. ; MHI-JrPrN

Yaw Head i ng : 30 deg.

Tw (sec)

D _{Ca] (MOORED)} _{+ Ca 1 (FREE)}

_{O MESLJRED}

(10)

1.3 1.2 -1.1 -

1'0.9

-0.8

0.?

-0.6

0.5

0.4

0.3 -

0.2-0.1

0-'

0

Mot ¡ons, Point

; MHI-JPN

SUrge Heading : 0 deg.

10

Tw (seo)

O Ca i (MOORED) + Ca i (FREE) 'C>

MESURED

O ₂₀ ₃₀

Tw (sec)

D _C _{i (MOORED)} _{+ Ca 1 (FREE)} _'C> _MEÍSLJRED

Mot ¡ ons,. Po ¡ nt I ; MH I -JrPrN Surge Head i ng : 30 deg.

20

¡ _I

(11)

1.3

1.2

1.1 -

1-0.9

0.8

0.7 -

0.6'0.5

-0.4

0.3 -0.1

0-'

0

'1.3

1.2

1.1 -

10.9

0.8

0.7

0.6

0.5

0.3

0.2 -0.1

-

0-Mot i on, Po i rit

;

MH I -JPN

Sway

Heading: 30 deg.

io

I I

'--I-.

-10

20

30

Tw (sec)

D Cal(MOURED)

± Cai(FREE)'

O MEASURED

I I.

10

20

30

Tw (sec)

D Ca i (MOORED)

± Ca i (FR)

' MESURED

Mot i ons, Po i nt

;

MH I -JPN

(12)

Mot ions, Po ¡ nt

_{; MHI-JPN}

Heave

Heading :

deg.

11

Tw (sec)

D Ca i (MOORED)

_{+ Ca]}

(FREE) ° MEASURED

Motions, Point

_{; MHI-JPN}

Heave Head i ng :

3 deg.

Tw (sec)

(13)

Moti QflS, Po, nt

; MHI-JPN

Heave Head ¡ ng : 90 deg.

Tw(sec)

Ö Ca i (MOORED) + Ca i (FREE)

O MESURED

(14)

2.2

-

21.8 1.6 -1.4 1.2

-

10.8

0.6

0.4

-@. 2 O

22 -

2-1.8 -1.6 -; 1.4 -1 2 1 0.8 0.6 0.4 -O

cce1erat ions, Point B

_{; MHI-JPN}

Tu (ec)

D Ca] (MOORED) + Cal (FREE)

O MSUR.

ccelerat ions, Point B ; MHI-JPN Surge Head I ng : 30 deg..

Tw(sec)

D _{Cal (MOORED)} _{± Cal (FREE)} O

_1ESUR

13 .---.. CI 'A 3 t 10 20 30

(15)

cce1 erat ¡ ans, Pö i nt B ; MHI-JPN

Swa.i Heading : 30 deg.

Tw(sec)

D Cal (MOORED) ± Cal (FREE)

<).MESURED

cce1erat ¡cris, Point B ; MHI-JPN Swap _Heading : 90 deg. 2.5

Tw (sec)

D Ca i (MOORED) + Ca I (FRE) o MEASURED

14

(16)

4

a

icce1erat ions, Point B ; MHI-JPN Heave Heading : 0 deg.

Tw (sec)

D Cal (MOORE])) + Cal (FREE) <) MEÇSURED

ooelerat ions, Point B ; MHI-JPFN Heave Heading : 30 dea.

10 20

Tw (sec)

D Cal(MOORED) _{+ Cal(FREE)} O _MEIS1JRED

(17)

I

cce1erat ions, Point B ; MHI-JPrN

Heave

Head i ng

:

90 deg.

16

'V -.

O 1: _..

-0

I".

Tw (sec)

(18)

Rel at i ve Mot ¡ ons, Po i nt C, D ; MH I -JPN

Po i nt C Head i ng @ deg

1w (sec)

D Ca i (MOORED) ± Ca] (FREE) O MEASURED

Relative Motions, Point CID ;MHI-JAPAN

Poi nt C Head i ng : 3 deg.

Tw (sec)

D Cai (MOORED) + Ca i (FREE) O _MEASURED

(19)

4

2 I

Rel at i ve Mot i ans, Po i nt C, D ;

MH I -JP1PPN

Pöint C

Heading

:

93 deg.

Tw (sec)

D Cal (MOORs)

+ cal (FREE)

O MEASURED

18

(20)

3

O

Rel at i ve Mot i ons, Po i nt C,

;

MH I JiiPN

Po i nt D

Head i ng :

0 deg.

I i I

r

10 ₂₀ 30

Tw (seà)

D Ca I (MOORED)

+ Ca (FREE)

<> MES1JRD

Rel at i ve Mot i ans, Po i nt C, D

;

MH I JPN

Po ¡ nt D

Head ¡ ng :

30 deg.

Tw (sec)

D Ca (MOORED) -i- _{Ca i (FREE)} _{<) MESURED}

(21)

Rel at i ve Mot i ans, Po i nt C, D ; MH I -JPN

Po ¡ nt D

Head i ng :

90 deg.

Tw (sec)

D Ca 1 (MOORED) .+ Ca 1 (FREE) <) MEISURED

20

(22)

0.1 .0

ai

--0.2 0.3 0.4 0.5 --0.6 -0.7 -0.8 0.9 -.. -..-..-..-..- s. -.

.... r:

tV2flS

-Mea n Wave Dr i ft Forces ; MH I -JÇPÇN

Tw (sec)

D Ca i (MOORED) . + Ca] (FREE) G MEISURED

Mea n Wave Dr i ft Forces

_{; MHI-JPN}

Surge Reading : 30 deg.

Tw (sec) Û Ca i (MOORED) - + Ca I (FREE) O tIEciSLJRED 21 L

L

i 10 . 20 30 0.1 0 -0.1 -0.2 -0.3 -0.4 -0.5 -0.6 -0.8 -0.9 -1

(23)

-1.2

-1.4 O

Mean Wave Drift Forces .; MHI-JPN Swa Head i ng : 30 deg.

0.6

--0.8

I I ¡

10 20 30

Tw (sec)

D _{Ca i (MOORs)} _{± Ca i (FREE)}

_{O MESUR}

Mea n Wave Dr i ft Forces ; MH I -JPN

Swa ' Head i ng : 90 deg.

22

0.2

0

-0.2

(24)

0.03 0.02 0. 01 O -0.01 -0.02 -0. 03 -0. 04 -0.05

Mean Wave Dr i ft Forces

_{; MHI-JPN}

Head i ng : 30 deg.

I j i

20 30

1w (sec)

D Cal (MOORED) ± Ca i (FREE) < MEASURED

23