16.5 Computer Program for the Free Vibration Analysis of Ships …
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all eigenvalues are calculated. As the size of the matrices is rather small for this
problem, no attempt has been made to make arrangements for the economic storage
of matrices.
Input data are presented for the oil tanker given in Example 11.1. Table 16.7. Data
included all the particulars of 20 solutions at which the ship is divided. Output given
in Table 16.8 contains only the natural frequencies and mode shapes for first four
modes.
Table 16.6 Computer program for free vibration analysis of ships by the flexibility matrix method
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DETERMINATION OF NATURAL FREQUENCIES AND MODE SHAPES OF SHIPS
DIMENSION A(50,50),AM(30),AA(50),BB(50),X(50),T(50,50)
DIMENSION AI(50),XX(50),AS(50)
DIMENSION Y(50),YN(50),YON(50),YNN(50),A1(50),B1(50)
DIMENSION XON(50),ADDM(50),YS(50),YT(50),YZ(12),CRLC(50)
DIMENSION ADDC(50)
DIMENSION AMM(50),DIF(50,50),ASEC(50),AC(50,50)
COMMON A,T
OPEN(10,FILE='sin.dat')
OPEN(12,FILE='sout')
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MATRIX ANALYSIS OF FREE VIBRATION OF SHIPS
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ALL UNITS ARE IN METERS AND TONNES
E=2.076*(10.0**7.0)
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MOD IS THE NUMBER OF MODES FOR WHICH FREQUENCIES ARE TO BE
STUDIED
READ(10,*)MOD,N,D
G=9.81
READ(10,*)(YZ(I),I=1,MOD)
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D=DISTANCE BETWEEN THE STATIONS
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N=TOTAL NUMBER OF STATIONS
MODE=1
L=N-1
READ(10,*)(AI(I),I=1,N)
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AI IS THE MOMENT OF INERTIA AT N STATIONS
DO 305 I=1,N
AI(I)=AI(I)*E
BX=I-1
XX(I)=D*BX
305 CONTINUE
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READ(10,*)(XX(I),I=1,N)
DO 2 I=2,N
CALL INCOF(AI,XX,N,I,D,AS)
LL=I-1
DO 2 J=1,L
AC(J,LL)=AS(J)
2 CONTINUE
READ(10,*)(AMM(I),I=1,N)
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AMM=WEIGHT AT N STATIONS
READ(10,*)(ADDM(I),I=1,N)
READ(10,*)(ASEC(I),I=1,N)
DK=0.0
I=1
902 J=I+1
DIF(I,I)=DK+(2.6*D)/(E*ASEC(J))
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DIF(I,I)=DK+(2.6*D)/(ASEC(J))
(continued)