S - GM< - II M> = .00777 <>:>50) - .or.i:; ion 

 51 



Impact factor = TTQ = .833 



Impact stress = .833 X 46 = 38*. 



Lower Chord Member AC = AD. 



Formula . & == */, " ^ ..... (21) 



Refer to Fig. 11 for definition of dimensions. 

 = J (.03125) = .00390 



//=-- = .0812 

 v 



Try tr, at panel ix.int 1. Use Table 2. L, = 200'. " 



(/ \ D 



|-ir 4 -ir 3 )=- 



Tlierefore i^ 4 at 1 gives a maximum. 

 S = CM, - HM* = .00390(63111) -- .0312(000) 

 = 247 -- 19 = 228*. 



300 

 Impact factor = = .600 



Impact stress == .600 X 228 137*. 



End of Post BC. 

 Formula S, = S, ........ (22) 



5. = ; ( (228) = /, and impact - 137)= 217*. 



Lower Chord M< tuber AH. 

 Formula S, = .17 - M 3 . . . . (21) 



