16.4 Computer Program for Free Vibration Analysis of Framed Structures
577
Table 16.3 (continued)
DO 20 I=1,N
DO 20 J=LOCK,M
20
U(I,J)=W(I,J)
IF(LET-1)15,10,15
15
CONTINUE
IF(NOI-INT)11,16,16
16
CONTINUE
INT=INT+1
GO TO 50
10
IER=0
GO TO 120
11
IER=1
120
CALL R8UBAC(ND,U,W,NK,N,M,1)
DO 121 J=1,M
EL=0.0
IF(BD(J) .LE. 0.0) GO TO 140
IF(J .LE. NRQD) BD(J)=1./SQRT(BD(J))
140
CONTINUE
DO 122 I=1,N
IF(ABS(W(I,J))-EL)130,130,125
125
CONTINUE
EL=ABS(W(I,J))
130
CONTINUE
122
CONTINUE
IF (EL .EQ. 0.) GO TO 150
EL=1./EL
DO 123 I=1,N
123
W(I,J)=W(I,J)*EL
121
CONTINUE
150
CONTINUE
PI=ATAN(1.)*4.
DO 135 I=1,NRQD
BD(I) = ABS(BD(I)*BD(I)-ALPHA)
BD(I) = SQRT(BD(I))
HZ(I) = BD(I)/2./PI
HZ(I) = SQRT(BD(I))
135
CONTINUE
WRITE(2,216)
216
FORMAT(/12X,'***** FREE VIBRATION RESULTS *****')
WRITE(2,211)INT,IER
211
FORMAT(/'ITEARATION = ',I5,4X,'ERROR CODE = ',I5)
WRITE(2,212)(I,BD(I),HZ(I),I=1,NRQD)
PRINT 212,(I,BD(I),HZ(I),I=1,NRQD)
212
FORMAT(/'EIGENVALUES ARE'/'Mode
in rad/sec
> in Hz'/(I3,5x,F15.8,3x,F15.8))
WRITE(2,213)
213
FORMAT(/'MODE SHAPES')
DO 210 I=1,NRQD
210
WRITE(2,214)I,BD(I),(LL1,(W((LL1-1)*6+J,I),J=1,6),LL1=1,NNF/6)
214
FORMAT(/'MODE SHAPE = ',I3,10X,'NATURAL FREQUENCY = ',F12.6,
>/(I3,6G12.4))
*
WRITE(2,215)(I,ERR(I),I=1,NRQD)
215
FORMAT(/'ERROR :',/(I3,5X,G15.6))
RETURN
END
**************************SUBROUTINE R8URED******************************
SUBROUTINE R8URED(NK,N,IER)
**
DECOMPOSES A SYMMETRIC MATRIX INTO CHOLESKY FACTORS
**
COMMON/A/NNF,NBH,L(7500),G(7500),GL(300),LD(300),GD(300)
INTEGER Q,GD
REAL L
(continued)