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16 Computer Programs in Vibration Analysis
Table 16.3 (continued)
tra(3,1) = (cx*cy*sina-cz*cosa)/cxz
tra(3,2) =-cxz*sina
tra(3,3) = cy*cz*sina+cx*cosa/cxz
endif
do iro=1,3
do jro=1,3
do jco=1,3
ir=iro*3+jro
ic=iro*3+jco
tra(ir,ic) = tra(jro,jco)
enddo
enddo
enddo
return
end
*
Subroutine to calculate the global stiffness matrix of the element
subroutine ttkt(iel,estif,tra,estg)
dimension estif(12,12),estg(12,12),tra(12,12),est(12,12)
do iro=1,12
do ico=1,12
est(iro,ico) = 0.0
do jro=1,12
est(iro,ico)=est(iro,ico)+tra(jro,iro)*estif(jro,ico)
enddo
enddo
enddo
do iro=1,12
do ico=1,12
estg(iro,ico) = 0.0
do jro=1,12
estg(iro,ico)=estg(iro,ico)+est(iro,jro)*tra(jro,ico)
enddo
enddo
enddo
return
end
*
Subroutine to calculate the global mass matrix of the element
subroutine elmas(iel,dens,len,emas)
parameter (ielt=50,inod=50,ntdf=inod*6,inb=50)
common /c/ area(ielt),ixx(ielt),iyy(ielt),izz(ielt)
dimension emas(12,12)
real len,ixx,iyy,izz,mass
mass = dens*area(iel)*len/2.
do iro=1,12
do ico=1,12
emas(iro,ico) = 0.0
(continued)