Complex Diaphragms With Combined Openings and Offsets - The Analysis of Irregular Shaped Structures - page 316

Force diagrams at grid line A starting at line 1, in accordance with sign convention
at the bottom of the figure (see Fig. 8.26):

F =− 84 25 () =− 2100 lb compression at startofSW4

F 2 =− 2100 + 586 04 5 . () = + 830 lbtension at grid line2

F 3 =+ 830 576 220 2 354 2 .( ) =+ , . btension at enddofSW4

F 5 = 12 354 22125 1 829 2 , . − () =+ , . lb tensionatgrid line5

F = 11 829 2918813 0 643 , . − . () =+ , lb tensionatstartofSW8

F 6 = 10 643 , + 578 16 12 . () =+ 17 572 68 , . lb tensionat grid line6

F = 17 572 68 , . + 366 43 8 0 504 12 . () =+ , . lbtension at endofSW8

F 9 = 20 504 12 , . − 303 61 62 . () =+ 1680 lbtension at grid line9

F 10 = 1680 − 84 20 () = 0 lb at grid line 10

Therefore the diagram closes.
Force diagrams at grid line A.2 (see Fig. 8.26):

F 3 = (. 51 84 − 38 72 . () 20 =+ 262 4 . btension

F 5 = 262 22125 . − ( ) =− 262 6 . lb compression

F 6 =− 262 6 9883937250 . + ( . − . )( ) = lb

Therefore the diagram closes.
Force diagrams at grid line B, starting at line 1 (see Fig. 8.27):

F 2 =− 84 30 () =− 2520 lb compression at grid linee2

F 3 =− 2520 − (. 87 28 + 84 20 )( ) =− 5945 6 . lb compressionatgrid line3

F i g u r e 8.27 Longitudinal strut/collector forces at grid line B.