Using opensees recently built a 3 span simply supported single girder bridge,Regardless of the collision,Each beam placed 4 bearings,node 2 is beam's node,node 102 and node 103 are the bearing's upper point,and i use "element elasticBeamColumn"command to connect the node 2 and node 102,node 2 and 103,the element elasticBeamColumn's E is 100 times concrete's E.Node 90 and node 91 are the bearing's bottom nodes,node 140 is the pier top node, i use "rigidlink" to connect them.Node 90 and node 102 are the same node,node 91 and node 103 are the same node.The two bearings are the movable supports,by using "equalDOF"to control, one is only x dire can move,one is x and y dire can move. When i perform modal analysis,the mode shape is wrong,where is wrong?
node 1 0.000 0.000 0.000
node 2 0.750 0.000 0.000
node 3 1.500 0.000 0.000
node 4 2.000 0.000 0.000
node 5 2.359 0.000 0.000
node 6 2.989 0.000 0.000
node 7 3.300 0.000 0.000
node 8 5.300 0.000 0.000
node 9 7.300 0.000 0.000
node 10 9.300 0.000 0.000
node 11 11.300 0.000 0.000
node 12 13.300 0.000 0.000
node 13 15.300 0.000 0.000
node 14 17.300 0.000 0.000
node 15 19.300 0.000 0.000
node 16 21.300 0.000 0.000
node 17 23.300 0.000 0.000
node 18 25.300 0.000 0.000
node 19 27.300 0.000 0.000
node 20 29.300 0.000 0.000
node 21 29.611 0.000 0.000
node 22 30.241 0.000 0.000
node 23 30.600 0.000 0.000
node 24 31.100 0.000 0.000
node 25 31.850 0.000 0.000
node 26 32.600 0.000 0.000
node 90 0.750 0.000 -2.350
node 91 0.750 0.000 2.350
node 102 0.750 0.000 -2.350
node 103 0.750 0.000 2.350
node 140 -0.250 0.000 0.000
rigidLink beam 140 90
rigidLink beam 140 91
set E [expr 3.55e10*$Pa]
set G [expr 1.42e10*$Pa]
set Eb [expr 3.55e12*$Pa]
set Gb [expr 1.42e12*$Pa]
set Ab 13.7980
set Jb 34.3266
set Ib 1e12
geomTransf Linear 5 0 1 0
element elasticBeamColumn 300 102 2 $Ab $Eb $Gb $Jb $Ib $Ib 5
element elasticBeamColumn 301 2 103 $Ab $Eb $Gb $Jb $Ib $Ib 5
equalDOF 90 102 2 5
equalDOF 91 103 2 3 5
the problem of modal analysis
Moderators: silvia, selimgunay, Moderators
the problem of modal analysis
Last edited by isolator on Tue Apr 09, 2013 6:56 pm, edited 1 time in total.
Re: the problem of modal analysis
node 25 31.850 0.000 0.000
node 92 31.850 0.000 -2.350
node 104 31.850 0.000 -2.350
node 105 31.850 0.000 2.350
node 93 31.850 0.000 2.350
element elasticBeamColumn 302 104 25 $Ab $Eb $Gb $Jb $Ib $Ib 5
element elasticBeamColumn 303 25 105 $Ab $Eb $Gb $Jb $Ib $Ib 5
equalDOF 92 104 1 2 5
equalDOF 93 105 1 2 3 5
set k1 [expr 1e12*$K]
set k2 [expr 3.8182e7*$K]
set k3 [expr 1e2*$Kzeta]
uniaxialMaterial Elastic 1 $k1
uniaxialMaterial ElasticPP 2 $k2 0.00451
uniaxialMaterial Elastic 3 $k3
element zeroLength 230 90 102 -mat 1 2 2 1 3 3 -dir 1 2 3 4 5 6 -orient 0 1 0 0 0 1
element zeroLength 231 91 103 -mat 1 2 2 1 3 3 -dir 1 2 3 4 5 6 -orient 0 1 0 0 0 1
element zeroLength 232 92 104 -mat 1 2 2 1 3 3 -dir 1 2 3 4 5 6 -orient 0 1 0 0 0 1
element zeroLength 233 93 105 -mat 1 2 2 1 3 3 -dir 1 2 3 4 5 6 -orient 0 1 0 0 0 1
node 92 31.850 0.000 -2.350
node 104 31.850 0.000 -2.350
node 105 31.850 0.000 2.350
node 93 31.850 0.000 2.350
element elasticBeamColumn 302 104 25 $Ab $Eb $Gb $Jb $Ib $Ib 5
element elasticBeamColumn 303 25 105 $Ab $Eb $Gb $Jb $Ib $Ib 5
equalDOF 92 104 1 2 5
equalDOF 93 105 1 2 3 5
set k1 [expr 1e12*$K]
set k2 [expr 3.8182e7*$K]
set k3 [expr 1e2*$Kzeta]
uniaxialMaterial Elastic 1 $k1
uniaxialMaterial ElasticPP 2 $k2 0.00451
uniaxialMaterial Elastic 3 $k3
element zeroLength 230 90 102 -mat 1 2 2 1 3 3 -dir 1 2 3 4 5 6 -orient 0 1 0 0 0 1
element zeroLength 231 91 103 -mat 1 2 2 1 3 3 -dir 1 2 3 4 5 6 -orient 0 1 0 0 0 1
element zeroLength 232 92 104 -mat 1 2 2 1 3 3 -dir 1 2 3 4 5 6 -orient 0 1 0 0 0 1
element zeroLength 233 93 105 -mat 1 2 2 1 3 3 -dir 1 2 3 4 5 6 -orient 0 1 0 0 0 1