m BEAMS SUBJECTED TO TEAJfSVEESE STEAIN. 
4 09 
In the case of the section No. 15, broken with the flanges horizontal (see flg. 1), 
D= depth. 
h = breadth of the centre rib. 
b' =. breadth of the flanges ae-\-fd. 
d = half-distance of the flanges. 
The exnression for the centre rib is 
and for the flanges 
2b'f/W-d^\ 
3 \ I) '' 
Eig. 1. 
and consequently the resistance to the whole section will be 
f(5D= 
b'(D^-d^) 
D 
=iZW. 
(5.) 
In like manner, for section No. 16, broken with the flanges vertical (see flg. 2), 
d = half-depth of the flange abed, 
b — width of the two flanges =lie-^ca. 
d'= depth of the centre rib. 
b' = breadth of the centre rib between the flanges. 
Then 
and 
2fbd^ 
3 ' 
2fb'd'^ 
resistance of the flanges. 
3d 
= resistance of centre rib ; 
and consequently the total resistance will be 
2/ 
Eig. 2. 
( 6 .) 
With these formulae we are enabled to calculate the resistance of the outer flbre 
under this generally accepted theory, in each of the sections. 
The following Table shows the results : — 
Eorm of section. 
Length 
of bearing, 
in. 
Breaking 
weight. 
lbs. 
Valne of^^ or the 
calculated resistance 
at the outer fibre. 
No. 
6. 
Open gii’der 
. 60 
5147 
25,271 
No. 
7. 
Open girder 
. 60 
6000 
27,908 
No. 
4. 
Open girder ; 
. 60 
4339 
28,032 
No. 
3. 
Open girder 
. 60 
3119 
31,977 
No. 
2. 
Open girder 
. 60 
2468 
35,386 
No. 
5. 
Open girder 
. 60 
5141 
37,408 
No. 
1. 
Solid rectangular 2x1 inches 
. 60 
1888 
41,709 
No. 
8. 
Square 1x1 inch .... 
. 60 
527 
45,630 
No. 
9. 
Round bar linch area. 
. 60 
474 
51,396 
No. 10. 
Square bar broken diagonally 
. 60 
449 
53,966 
