70 lines
2.1 KiB
Text
70 lines
2.1 KiB
Text
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subroutine uel(rhs,amatrx,svars,energy,ndofel,nrhs,nsvars,
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1 props,nprops,coords,mcrd,nnode,u,du,v,a,jtype,time,
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2 dtime,kstep,kinc,jelem,params,ndload,jdltyp,adlmag,
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3 predef,npredf,lflags,mlvarx,ddlmag,mdload,pnewdt,
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4 jprops,njprop,period)
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c
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include 'aba_param.inc'
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parameter ( zero = 0.d0, half = 0.5d0, one = 1.d0 )
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c
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c This is a linear truss element for Abaqus/Standard
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c general static analysis in 1D space (aligned to x-axis) only.
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dimension rhs(mlvarx,*),amatrx(ndofel,ndofel),
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1 svars(nsvars),energy(8),props(*),coords(mcrd,nnode),
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2 u(ndofel),du(mlvarx,*),v(ndofel),a(ndofel),time(2),
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3 params(3),jdltyp(mdload,*),adlmag(mdload,*),
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4 ddlmag(mdload,*),predef(2,npredf,nnode),lflags(*),
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5 jprops(*)
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c
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c assign section properties
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area = props(1)
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e = props(2)
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anu = props(3)
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rho = props(4)
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c calculate stiffness and mass
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alen = abs(coords(1,2)-coords(1,1))
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ak = area*e/alen
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am = half*area*rho*alen
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c Initialize Arrays
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rhs = zero
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amatrx = zero
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if (lflags(3).eq.1) then
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C Stiffness and Force
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C Get Stiffness Matrix
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amatrx(1,1) = ak
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amatrx(4,4) = ak
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amatrx(1,4) = -ak
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amatrx(4,1) = -ak
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c Get Internal Contrib to Residual Force
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rhs(1,1) = -ak*(u(1)-u(4))
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rhs(4,1) = -ak*(u(4)-u(1))
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c Get External Contrib to Residual Force
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do kdload = 1, ndload
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if (jdltyp(kdload,1).eq.1001) then
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rhs(4,1) = rhs(4,1)+adlmag(kdload,1)
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end if
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end do
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else if (lflags(3).eq.2) then
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c Stiffness
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amatrx(1,1) = ak
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amatrx(4,4) = ak
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amatrx(1,4) = -ak
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amatrx(4,1) = -ak
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else if (lflags(3).eq.4) then
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c Mass
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do k1 = 1, ndofel
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amatrx(k1,k1) = am
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end do
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else if (lflags(3).eq.5) then
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print *,'oops'
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else if (lflags(3).eq.6) then
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C Mass and Force
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do k1 = 1, ndofel
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amatrx(k1,k1) = am
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end do
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rhs(1,1) = -ak*(u(1)-u(4))
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rhs(4,1) = -ak*(u(4)-u(1))
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END IF
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c
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return
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end
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