pushover analysis

[dengjdong]

ERROR: Permanent Loading
-----------------------------------------

LF= 0.00000, LF_incr= (Iter: 1 => fbd_Inv)
LF= 0.00000, LF_incr= (Iter: 1 => fbd_Inv)
LF= 0.00000, LF_incr= (Iter: 1 => fbd_Inv)
LF= 0.00000, LF_incr= (Iter: 1 => fbd_Inv)
-----------------------------------------
Unable to apply the entire permanent load. Analysis terminated
Total Analysis Time: 0h:0min:0sec


why?

[huffte]

You might find it helpful to do a searh on 'fbd_inv' in the SeismoStruct Help system and on this forum as well. You will get several hits and some suggestions on possible causes of this error.

Best of luck.

[dengjdong]

Thanks. But I can not find the reason. The model is quite easy,




/&SeismoStruct file&/
/&Vrs 47&/
5.2.2 10
3
/&Start of list&/
C16/20 con_ma 30000. 0. 0.002 1.2 24.
S400 stl_mp 2.1000E+008 450000. 0.0005 20. 18.5 0.15 0. 1. 0.1 78.
/&End of list&/
/&Start of list&/
normal rcrhs S400 C16/20 C16/20 0.32 0.18 0.44 0.26 ext_corners(4@8mm) ext_sides(12@8mm) int_corners(4@8mm) int_sides(4@8mm) 0.
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
normal normal 8 400 -1e20 1e20
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
1 0. 0. 0. structural
2 4200. 0. 0. structural
3 0. 0. 1. non-structural
/&End of list&/
/&Start of list&/
nor normal 1 2 3
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
1 x+y+z+rx+ry+rz
2
/&End of list&/
/&Start of list&/
line User-Defined - 1. 1.
/&End of list&/
/&Start of list&/
Incremental Load 2 y force 1000
/&End of list&/
/&Start of list&/
Response Control 50 2 y 0.0000000003
/&End of list&/
/&Start of list&/
0.0 1 10 0.1
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
/&End of list&/
/&Start of list&/
0 1 100 1
1 0.04 1 0 0 0 0 0 -1 0 0.85
0 1 2 4 5000 0.02 0

2 2




/&End of list&/
/&Start of list&/
1 1000. 1000000.
1 2
1 2
x y z rx ry rz
0 0 1 true
0 0
2 true 1 true
nor true
nor true
/&End of list&/
/&Start of list&/
0 true false
0.1 1.0 0.3 1.0 2.0 3.0 0.5
2 1
2 1
-1 -1
/&End of list&/
/&Start of list&/
1 0
m kN tonne m/sec2 kPa kN/m3
0.025 1.0000000E-005 300 1 true 1.0000000E-005 300 1 true
2 -0.1 0.3025 0.6
40 35 2.0 1.5 1.0 0.5 0.25 0.125 32 1e20 0.001 1
0 1.0000000E-005 1e-5 0.0001 0.0001
1 4 4 4 10 50
0 0.02 0.02 0.7 0.3 4 6 0
0 10 7
0 -3
9.81 -z 1 1 1 1 1 1 1 1 1 0 1
/&End of list&/

[huffte]

I think you may have a problem with units. It appears from your material properties that units are set to:
meters for length
kN for force
kPa for stress

However, in your nodes, it appears that you were thinking in millimeters - you have input a geometry such that the length of the cantilever is 4200 meters. Perhaps if you change the coordinates of node 2 from 4200,0,0 to 4.2,0,0. (If, in fact, your length units are set to meters)

Additionally, you have specified a target displacement of 50 meters. Perhaps this number should be changed to 0.050? Again, if my suspicion that your units of length are meters.

Conversely if your length units are in fact millimeters, then you need to adjust your material properties - I am fairly certain the values you have there are for meter length units.

[dengjdong]

Thank you¡£[:)]