THE STRENGTH AND DUCTILITY OF FLAT STEEL BARS. 211 
In fig. 12 the curve of extension for a length equal to 11°3,/area, the Continental 
standard variable length, is plotted separately with a more open vertical scale; it has 
SZ 
_ 30 ee 
z 
[ey 
rs) 
ox 
a 28 eee Zo 
Zz FA 
° 
é ial 
7 
e ; 
& 26 
if 
a} 
@ 
= 
(eo) 
i. 24 
aa 7 4 6 8 10 [2 14 16 18 
WIDTH 
THICKNESS 
Fic. 12.—Similar to fig. 11, but with a gauge-length of 11°3 s/area, The vertical distance between the two curves is the 
breadth of the gap at fracture, expressed as a percentage of 11°3/area. 
much the same characteristics as those of fig. 11. Notice may be taken of the fact that 
the breadth of the gap varies almost directly as ./area, the two curves of fig. 12 being 
-hearly parallel. The data for fig. 12 are given in Table V. 
REDUCTION OF AREA PER CENT. 
8 1 
WIDTH 
THICKNESS 
Fic. 13.—Variation in reduction of area of flat steel test-pieces, with change in the ratio of width to thickness from 
2 to 16, and a constant thickness of } inch. 
6. RepucTION oF AREA. 
The reduction of wrea is the difference between the original cross-sectional area 
of the bar and the minimum area measured after fracture, expressed as a fraction 
. } 
- the original area; that is, the reduction of area is ee , Where Q and 
TRANS. ROY. SOC. EDIN., VOL. XLVIII. PART I. (NO. 10). 33 
4 
