i have a symmetric structure with symmetric loads..
how does staad generate notional loads?
i used the notional load feature in staad.pro v8i release 20.07.05.15, the generated loads are not symmetric.. why?
below is the input file i used..
STAAD SPACEINPUT WIDTH 79UNIT METER KNJOINT COORDINATES 1 0 5 0 2 0 5 4 3 4 5 4 4 4 5 0 5 0 0 0 6 0 0 4 7 4 0 4 8 4 0 0 9 0 7 0 10 0 7 4 11 4 7 4 12 4 7 0 13 0 7 2 14 2 7 4 15 4 7 2 16 2 7 0MEMBER INCIDENCES 1 1 2 2 2 3 3 3 4 4 4 1 5 5 1 6 1 9 7 6 2 8 2 10 9 8 4 10 4 12 11 7 3 12 3 11 13 9 13 14 10 14 15 11 15 16 12 16 17 13 10 18 14 11 19 15 12 20 16 9 21 1 13 22 2 13 23 2 14 24 3 14 25 4 15 26 3 15 27 4 16 28 1 16DEFINE MATERIAL STARTISOTROPIC STEELE 2.05e+008POISSON 0.3DENSITY 76.8195ALPHA 1.2e-005DAMP 0.03END DEFINE MATERIALMEMBER PROPERTY AUSTRALIAN1 TO 4 13 TO 20 TABLE ST UB150X14.05 TO 12 TABLE ST UC100X14.821 TO 28 TABLE ST A75X75X5CONSTANTSMATERIAL STEEL ALLMEMBER TRUSS 21 TO 28MEMBER RELEASE1 TO 4 13 TO 16 START MY MZ1 TO 4 17 TO 20 END MY MZSUPPORTS5 TO 8 FIXED BUT MX MZLOAD 1 LOADTYPE Dead TITLE LOAD CASE 1JOINT LOAD13 TO 16 FY -1LOAD 2 NOTIONAL XNOTIONAL LOAD1 X 0.002LOAD 3 NOTIONAL ZNOTIONAL LOAD1 Z 0.002PERFORM ANALYSIS FINISH
Use PERFORM ANALYSIS Print Static Loads to see the joint effective loads; these are symmetric. However the results are not symmetric because the cross sections are not aligned symmetrically. This would not matter if Iy and Iz were equal, but they are not.
I WILL LIKE TO GET CLARIFICATION. WHETHER NOTIONAL LOAD IS 2% OR 0.2%.
As per my vague rememberance it is somewhere between 1.5 and 2%.The file posted by Mr Magat speaks for 0.2%. Is it ok?
0.2% as per Appendix 7 of AISC 360-05