*heading
*node
 1, -1., -1., 0.
 2,  1., -1., 0.
 3,  1.,  1., 0.
 4, -1.,  1., 0.
 5, -1., -1., 0.1
 6,  1., -1., 0.1
 7,  1.,  1., 0.1
 8, -1.,  1., 0.1
 9,  0.,  0., 0.11
 11, -1., -1., -1.
 12,  1., -1., -1.
 13,  1.,  1., -1.
 14, -1.,  1., -1.
 21, -1., -1., -2.
 22,  1., -1., -2.
 23,  1.,  1., -2.
 24, -1.,  1., -2.
 25,  0.,  0.,  0.
 26,  0.,  0.,  0.1
*nset, nset=shella
 1,2,3,4
*nset, nset=shellb
 5,6,7,8
*element,type=s4,elset=shella
 1, 1,2,3,4
*element,type=s4,elset=shellb
 2, 5,6,7,8
*element, type=c3d8,elset=cubea
 3, 11,12,13,14,1,2,3,4
*element, type=c3d8,elset=cubeb
 4, 21,22,23,24,11,12,13,14
*element, type=dcoup3d, elset=dcoupa
 5, 25
*element, type=dcoup3d, elset=dcoupb
 6, 26
*element, type=b31, elset=connect
 7, 25, 26
*surface, name=scube
 3, s2
*shell section, elset=shella, material=mat2
 0.1, 5
*shell section, elset=shellb, material=mat1
 0.1, 5
*solid section, elset=cube, material=mat2
*distributing coupling, elset=dcoupa
 shella, 1.
*distributing coupling, elset=dcoupb
 shellb, 1.
*orientation, name=ori
 1.,0.,0., 0.,1.,0.
*beam section, elset=connect, section=circ, material=mat3
 0.1
 1.,0.,0.
*elset, elset=shell
 shella,shellb
*elset,elset=cube
 cubea,cubeb
*nset,nset=bot
 21,22,23,24
*nset,nset=shell,generate
 1, 8
*material, name=mat1
*elastic
 30.e6, 0.3
*density
 1.e2
*damping,alpha=.5e1
*material, name=mat2
*elastic
 30.e3, 0.3
*density
 1.e1
*damping,alpha=.5e1
*material, name=mat3
*elastic
 30.e9, 0.3
*density
 1.e-2
*boundary
 bot,1,3
 shell,4,6
*psd-definition, name=white, type=force
 1.0,0.1,0.0
 1.0,0.1,60.0
*spectrum, name=spec,type=acceleration
 0., 0., 0.
 1.e5, 10., 0.
 1.e5, 100., 0.
**
** --------------------------------------------------
**
*step, perturbation, name=step-1
 static 
*static
*node print, nset=bot, totals=yes
 rf3,
*el print, elset=connect
 sf,
*output,field,freq=0
*output,history,freq=0
*load case, name=load1
*cload
 5,3,1.
 6,3,1.
 7,3,1.
 8,3,1.
*end load case
*load case, name=load2
*cload
 5,3,2.
 6,3,2.
 7,3,2.
 8,3,2.
*end load case
*load case, name=load3
*cload
 5,3,3.
 6,3,3.
 7,3,3.
 8,3,3.
*end load case
*end step
**
** --------------------------------------------------
**
*step, name=step-2
 frequency analysis
*frequency 
 30,
*end step
**
** --------------------------------------------------
**
*step, name=step-3
 SSD mode-based
*steady state dynamics, interval=eigenfrequency
 15.,18.,7,3.
*cload
 5,3,1.
 6,3,1.
 7,3,1.
 8,3,1.
*global damping, alpha=.5e1
** Or you may use *modal damping  instead
**Modal Damping, rayleigh
** 1, 30, .5e1 
*node print, nset=bot, totals=yes
 rf3,
*el print, elset=connect
 sf,
*output,field,freq=0
*output,history
*node output, nset=bot
 rf3,
*element output, elset=connect
 sf1,
*end step
**
** --------------------------------------------------
**
*step, name=step-4
 modal dynamic
*modal dynamic
 0.1,1.
*cload
 5,3,1.
 6,3,1.
 7,3,1.
 8,3,1.
*global damping, alpha=.5e1
** Or you may use *modal damping  instead
**modal damping, rayleigh
** 1, 30, .5e1
*node print, nset=bot, totals=yes
 rf3,
*el print, elset=connect
 sf,
*output,field,freq=0
*output,history
*node output, nset=bot
 rf3,
*element output, elset=connect
 sf1,
*end step
**
** --------------------------------------------------
**
*step, name=step-5
 SSD direct
*steady state dynamics, direct, interval=eigenfrequency
 15.,18.,7,3.
*cload
 5,3,1.
 6,3,1.
 7,3,1.
 8,3,1.
*node print, nset=bot, totals=yes
 rf3,
*el print, elset=connect
 sf,
*output,field,freq=0
*output,history
*node output, nset=bot
 rf3,
*element output, elset=connect
 sf1,
*end step
**
** --------------------------------------------------
**
*step, name=step-6
 SSD subspace
*steady state dynamics, subspace projection, interval=eigenfrequency
 15.,18.,7,3.
*cload
 5,3,1.
 6,3,1.
 7,3,1.
 8,3,1.
*node print, nset=bot, totals=yes
 rf3,
*el print, elset=connect
 sf,
*output,field,freq=0
*output,history
*node output, nset=bot
 rf3,
*element output, elset=connect
 sf1,
*end step
**
** --------------------------------------------------
**
*step, name=step-7
 random response
*random response
 15.,18.,7,3.
*modal damping, rayleigh
 1, 5, .5e1 
*select eigenmodes, generate
 1,5
*cload, load case=1
 5,3,1.
 6,3,1.
 7,3,1.
 8,3,1.
*cload, load case=2
 5,3,1.
 6,3,1.
 7,3,1.
 8,3,1.
*correlation, psd=white, type=uncorrelated, complex=no
 1,1
 2,1
*node print, nset=bot, totals=yes
 rf3,
*el print, elset=connect
 sf,
*output,field,freq=0
*output,history
*node output, nset=bot
 rf3,
*element output, elset=connect
 sf1,
*end step
**
** --------------------------------------------------
**
*step, name=step-8
 response spectrum
*response spectrum, sum=abs, comp=alg
 spec,0.,0.,1.,1.
*modal damping, rayleigh
 1, 30, .5e1
*node print, nset=bot, totals=yes
 rf3,
*el print
 sf,
*output,field,freq=0
*output,history
*node output, nset=bot
 rf3,
*element output, elset=connect
 sf1,
*end step