Hi all -

I've been working with STAAD.Pro V8i  for just over a year and have never been able to really wrap my head around the Seismic Design engine within the software.  I've tried to read the documentation, look for tutorials online, etc. but I've had no real success.  I've created a really quick arbitrary structure with no loadings on it for an example.  I've got no idea what to do with the structure itself in order to do ANY sort of seismic analysis. 

So I pose my questions using the structure below as an example!

1)  How do I obtain the fundamental frequency of the structure as it stands? 

2)  If this structure were filled with a material (be it solid or liquid), how would you take that into account for determining the fundamental period?

3)  I know STAAD is able to calculate and generate the seismic loading for the structure, but how do I tell it to do that?  What sort of parameters do I need and how do I even begin to do this?

Hopefully someone is able to help me out!  Even a good book/article/tutorial that really describes and makes sense of the seismic parameters and processes of STAAD would be helpful.  I want to understand how to use this information for future projects, rather than for random structures I scribble up in the editor.  I appreciate any help!

As I'm not at my office computer, I'll post the input file (which I DO have).  Hopefully, I can get some idea on how to understand seismic "stuff" in STAAD soon!

STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 23-Jan-12
END JOB INFORMATION
INPUT WIDTH 79
UNIT FEET KIP
JOINT COORDINATES
1 -1 0 0; 2 -0.5 0 0.866025; 3 0.5 0 0.866025; 4 1 0 1.22461e-016;
5 0.5 0 -0.866025; 6 -0.5 0 -0.866025; 7 -1 1.66667 0;
8 -0.5 1.66667 0.866025; 9 0.5 1.66667 0.866025;
10 1 1.66667 1.22461e-016; 11 0.5 1.66667 -0.866025;
12 -0.5 1.66667 -0.866025; 13 -1 3.33333 0; 14 -0.5 3.33333 0.866025;
15 0.5 3.33333 0.866025; 16 1 3.33333 1.22461e-016;
17 0.5 3.33333 -0.866025; 18 -0.5 3.33333 -0.866025; 19 -1 5 0;
20 -0.5 5 0.866025; 21 0.5 5 0.866025; 22 1 5 1.22461e-016;
23 0.5 5 -0.866025; 24 -0.5 5 -0.866025; 25 -1 6.66667 0;
26 -0.5 6.66667 0.866025; 27 0.5 6.66667 0.866025;
28 1 6.66667 1.22461e-016; 29 0.5 6.66667 -0.866025;
30 -0.5 6.66667 -0.866025; 31 -1 8.33333 0; 32 -0.5 8.33333 0.866025;
33 0.5 8.33333 0.866025; 34 1 8.33333 1.22461e-016;
35 0.5 8.33333 -0.866025; 36 -0.5 8.33333 -0.866025; 37 -1 10 0;
38 -0.5 10 0.866025; 39 0.5 10 0.866025; 40 1 10 1.22461e-016;
41 0.5 10 -0.866025; 42 -0.5 10 -0.866025; 43 -2.87939 10.3333 -0.68404;
44 -2.03209 10.3333 2.1516; 45 0.847296 10.3333 2.83564;
46 2.87939 10.3333 0.68404; 47 2.03209 10.3333 -2.1516;
48 -0.847296 10.3333 -2.83564;
MEMBER INCIDENCES
37 31 43; 38 43 37; 41 43 44; 42 32 44; 43 44 38; 46 44 45; 47 33 45;
48 45 39; 51 45 46; 52 34 46; 53 46 40; 56 46 47; 57 35 47; 58 47 41;
61 47 48; 62 36 48; 63 48 42; 66 48 43;
ELEMENT INCIDENCES SHELL
1 1 2 8 7; 2 2 3 9 8; 3 3 4 10 9; 4 4 5 11 10; 5 5 6 12 11; 6 6 1 7 12;
7 7 8 14 13; 8 8 9 15 14; 9 9 10 16 15; 10 10 11 17 16; 11 11 12 18 17;
12 12 7 13 18; 13 13 14 20 19; 14 14 15 21 20; 15 15 16 22 21;
16 16 17 23 22; 17 17 18 24 23; 18 18 13 19 24; 19 19 20 26 25;
20 20 21 27 26; 21 21 22 28 27; 22 22 23 29 28; 23 23 24 30 29;
24 24 19 25 30; 25 25 26 32 31; 26 26 27 33 32; 27 27 28 34 33;
28 28 29 35 34; 29 29 30 36 35; 30 30 25 31 36; 31 31 32 38 37;
32 32 33 39 38; 33 33 34 40 39; 34 34 35 41 40; 35 35 36 42 41;
36 36 31 37 42;
ELEMENT PROPERTY
19 TO 36 THICKNESS 0.020833
1 TO 18 THICKNESS 0.041667
DEFINE MATERIAL START
ISOTROPIC STEEL
E 4.176e+006
POISSON 0.3
DENSITY 0.489024
ALPHA 6e-006
DAMP 0.03
TYPE STEEL
STRENGTH FY 5184 FU 8352 RY 1.5 RT 1.2
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
37 38 41 TO 43 46 TO 48 51 TO 53 56 TO 58 61 TO 63 66 TABLE ST W4X13
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
1 TO 6 FIXED
FINISH