Hi
Three questions regarding the response spectrum analysis.
Q1:
I am not quite sure why I got zero on the Y and Z directions? Please advise.
LOAD 4 LOADTYPE
Seismic TITLE RESP. SPECTRUM LOADS X
MEMBER LOAD
15 TO 20 35 TO 40 UNI
GX 10
15 TO 20 35 TO 40 UNI
GY 10
15 TO 20 35 TO 40 UNI
GX 200
15 TO 20 35 TO 40 UNI
GY 200
5 6 25 26 UNI GX 150
5 6 25 26 UNI GY 150
SPECTRUM SRSS IBC 2006
X 1 ACC DAMP 0.05
ZIP 2908 SITE CLASS D
FA 1.600 FV 2.400 TL 6.000
SELFWEIGHT X 1 LIST 5 6
15 TO 20 25 26 35 TO 40
SELFWEIGHT Y 1 LIST 1
TO 4 7 TO 14 21 TO 24 27 TO 34
SELFWEIGHT Z 1 LIST 41
TO 52
*
PERFORM ANALYSIS
CHANGE
*
LOAD 5 LOADTYPE
Seismic TITLE RESP. SPECTRUM LOADS Y
MEMBER LOAD
15 TO 20 35 TO 40 UNI
GX 10
15 TO 20 35 TO 40 UNI
GY 10
15 TO 20 35 TO 40 UNI
GX 200
15 TO 20 35 TO 40 UNI
GY 200
5 6 25 26 UNI GX 150
5 6 25 26 UNI GY 150
SPECTRUM SRSS IBC 2006
Y 1 ACC DAMP 0.05
ZIP 2908 SITE CLASS D
FA 1.600 FV 2.400 TL 6.000
SELFWEIGHT X 1 LIST 5 6
15 TO 20 25 26 35 TO 40
SELFWEIGHT Y 1 LIST 1
TO 4 7 TO 14 21 TO 24 27 TO 34
SELFWEIGHT Z 1 LIST 41
TO 52
*
PERFORM ANALYSIS
CHANGE
*
LOAD 6 LOADTYPE
Seismic TITLE RESP. SPECTRUM LOADS Z
MEMBER LOAD
15 TO 20 35 TO 40 UNI
GX 10
15 TO 20 35 TO 40 UNI
GY 10
15 TO 20 35 TO 40 UNI
GX 200
15 TO 20 35 TO 40 UNI
GY 200
5 6 25 26 UNI GX 150
5 6 25 26 UNI GY 150
SPECTRUM SRSS IBC 2006
Z 1 ACC DAMP 0.05
ZIP 2908 SITE CLASS D
FA 1.600 FV 2.400 TL 6.000
SELFWEIGHT X 1 LIST 5 6
15 TO 20 25 26 35 TO 40
SELFWEIGHT Y 1 LIST 1
TO 4 7 TO 14 21 TO 24 27 TO 34
SELFWEIGHT Z 1 LIST 41 TO
52
*
PERFORM ANALYSIS
CHANGE
Q2:
The base shear results are less on the load case #1 (Seismic X) compared to load #4 (Response Spectrum in X). Why? I thought that the static analysis (V=Cs*W) shall be conservative compared to the dynamic analysis, right? Please advise.
Q3:
Why I got same results on the repeat load (load case #7) and load combination (load case #8)? Please advise.
Thanks again for the help.