IS, 6 
Valencia: Commercial Philippine Timbers 
509 
E = Modulus of elasticity, pounds per square inch. 
EL= Fiber stress at elastic limit, pounds per square inch. 
J — Greatest calculated longitudinal shear, pounds per square inch. 
K — 27.7 where weight is in pounds, and 0.061 where weight is in 
grams. 
MR= Modulus of rupture, pounds per square inch. 
P Maximum load, pounds. 
P' = Load at elastic limit, pounds. 
S = Dry specific gravity. 
W = Weight of specimen, pounds. 
A = Total deflection or compression at elastic limit, inches, 
b = Width, inches. 
d = Distance between centers of collars, inches, 
h = Height, inches. 
1 = Span, inches (compression, 1= length). 
BENDING 
Load applied 
at center. 
Uniformly distri- 
buted load. 
Load applied at 
third points. 
T 0.75XP T 0.75XP 
bXh ' bXh * 
• bXh 
~0.75XP* 
MR= 
1.5XPX1 
bXh 2 ' 
MR= 
0. 75XPX1 
bXb 2 
MR= 
lX (P+0.75 W) 
bXb 2 
EL= 
1.5 P'l 
bXh 2 ‘ 
EL= 
0.75XPX.J 
bXb 2 
EL— 
lX(P'+0.75 W) 
bXh 2 
P'Xl 2 P'xl 
~4XbXh 3 X A* E= 6.4XbXh 3 xA" 
P'Xl 3 
E= 4.7 bXh 3 XA* 
COMPRESSION PARALLEL TO GRAIN 
E= 
P'Xd 
Ax A 
COMPRESSION PERPENDICULAR TO GRAIN 
SHEARING PARALLEL TO GRAIN 
Shear=^-. 
A 
SPECIFIC GRAVITY 
S= 
(1 + per cent 
Wet weight X K 
moisture 
)X 
volume in cubic inches 
100 
