MECHANICAL PROPERTIES OE WOODS GROWN IN UNITED STATES. 25 



Uniformly distributed load: 

 0.75 XP 



J= 



MR = 



EL = 

 E 



bxh 

 0.75 xPxl 

 bxh 2 



0.75xP'xl 

 bxh 2 



P'Xl 3 



6.4xbxh 3 XA 

 Any loading: 



M=l/6Fxbxh 2 . 

 Where M = moment in inch-pounds either external or internal. 

 F = fiber stress for moment M. 



y 

 J = 3/2x i -, where J = unit horizontal shear at any 



point and V = total vertical shear at that point. 



COMPRESSION PARALLEL TO GRAIN. 

 P 



cs= x 



P' 



EL =X 



tj, Fxd 



E= A^A 



COMPRESSION PERPENDICULAR TO GRAIN. 



EL=: 



Shear =-r- 



SHEAR PARALLEL TO GRAIN. 



SPECIFIC GRAVITY. 



weight X K 



( 1 + % — ttjtj — ) X volume of piece in cubic inches 



