一 107 — 
V sec 〇 
sec 0 
^lucli can bo resisted only by tlio moment of a released weight V upon tlie foot F, 
thus 2 P d + 2 Pf (d— /) = F み 
and 2rf ( P + P f ) — 2 P f f 
b 
This released weiglit must pass up the vibration rod KG, causing a tension 
therein, represented by 
2 d( P + Pf) — 2 Pff 
b ^ — 
wliicli stress must be increased for initial tension. 
To find the stress on the strut JK pass a plane through the bracing cutting GH, 
GK and JK (HJ not being strained), take the centre of moments at G, and consider 
the forces acting on the leeward side of the truss, tlieu the moment of tlie stress in 
will balance the moments of and ^ H, thus 
{JK) = ±l ld ~ p, f P+F)- P， 
to which must be added the horizontal component of tlie initial tension in JH. 
(JK) represents tlie stress in JK. 
Tho stress iu GH is found by considering it a part of the upper lateral system 
a ud not to belong to the vertical sway bracing. But if it be supposed to belong to 
山 6 ^tter, its stress may bo found by passing a plane as before, taking tlie centre of 
foments at K, autl considering only tlie forces acting at the leeward side of the 
| lu ss, so that the moment of the stress iu GH will balance the moments of the 
orizoutal reaction at E and tlie pressure at G, tlie moment of the increase of weight 
at E balancing the moment of the increase of vertical reaction at that point ; thus 
い G 7/ = 」 " いヒ (1 f 二 + ( 十 1)， 卜 F 
0r equal to tlie stress in JK. 
The bending moment on tlie post, if tlie lower end bo considered free, would bo 
i 孖 w —/) = (p + 尸 j -: n 
as the foot of tlie post is rigidly attached to tlie floor beam, it may be considered 
as 丘 xet し Comparing these two conditions of the portion of the post between tlio 
foot and the iutermediatG strut, we see that they are similar to those of one hall* of a 
eam loaded at tlie middle, first with tlie ends supported and second with the cutis 
xe • It is well known that the bending moment in the latter case is only one half 
ブ tlhit iu the former, so we may conclude that the bending moment to be provUetl 
for is 
HP+ p，） （ d —/) 
m bo tlio distance between centres of gravity of post channels, tlio stress on one 
C iailne 】 produced by the bending will be 
一 2 m 
