phd-scripts/Unpublished/XFEM2/XFEM/JTruss.for

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2024-05-13 19:50:21 +00:00
subroutine uel(rhs,amatrx,svars,energy,ndofel,nrhs,nsvars,
1 props,nprops,coords,mcrd,nnode,u,du,v,a,jtype,time,
2 dtime,kstep,kinc,jelem,params,ndload,jdltyp,adlmag,
3 predef,npredf,lflags,mlvarx,ddlmag,mdload,pnewdt,
4 jprops,njprop,period)
c
include 'aba_param.inc'
parameter ( zero = 0.d0, half = 0.5d0, one = 1.d0 )
c
c This is a linear truss element for Abaqus/Standard
c general static analysis in 1D space (aligned to x-axis) only.
dimension rhs(mlvarx,*),amatrx(ndofel,ndofel),
1 svars(nsvars),energy(8),props(*),coords(mcrd,nnode),
2 u(ndofel),du(mlvarx,*),v(ndofel),a(ndofel),time(2),
3 params(3),jdltyp(mdload,*),adlmag(mdload,*),
4 ddlmag(mdload,*),predef(2,npredf,nnode),lflags(*),
5 jprops(*)
c
c assign section properties
area = props(1)
e = props(2)
anu = props(3)
rho = props(4)
c calculate stiffness and mass
alen = abs(coords(1,2)-coords(1,1))
ak = area*e/alen
am = half*area*rho*alen
c Initialize Arrays
rhs = zero
amatrx = zero
if (lflags(3).eq.1) then
C Stiffness and Force
C Get Stiffness Matrix
amatrx(1,1) = ak
amatrx(4,4) = ak
amatrx(1,4) = -ak
amatrx(4,1) = -ak
c Get Internal Contrib to Residual Force
rhs(1,1) = -ak*(u(1)-u(4))
rhs(4,1) = -ak*(u(4)-u(1))
c Get External Contrib to Residual Force
do kdload = 1, ndload
if (jdltyp(kdload,1).eq.1001) then
rhs(4,1) = rhs(4,1)+adlmag(kdload,1)
end if
end do
else if (lflags(3).eq.2) then
c Stiffness
amatrx(1,1) = ak
amatrx(4,4) = ak
amatrx(1,4) = -ak
amatrx(4,1) = -ak
else if (lflags(3).eq.4) then
c Mass
do k1 = 1, ndofel
amatrx(k1,k1) = am
end do
else if (lflags(3).eq.5) then
print *,'oops'
else if (lflags(3).eq.6) then
C Mass and Force
do k1 = 1, ndofel
amatrx(k1,k1) = am
end do
rhs(1,1) = -ak*(u(1)-u(4))
rhs(4,1) = -ak*(u(4)-u(1))
END IF
c
return
end