210 



JOHN C. KOCH 



In the above fonnulas 



/S„ = normal tensile stress (maximum or minimum). 



Sh = horizontal shearing unit-stress. 



S = longitudinal tensile unit-stress. 

 The same formulas may be applied to the determination of the 

 magnitudes and directions of the maximum or minimum normal 

 compressive stresses. 



Fig. 12 a Typical paths of the lines of maximum stress in a cantilever beam 

 of same over-hang and average size as femur analyzed in Part III. (See figure 

 14.) 



Nputral /)/r/5i 



Fig. 12 b Typical paths of the lines of maximum stress in beams on two 

 supports. 



By the use of these formulas the magnitudes and directions of 

 the maximum and minimum tensile and compressive stresses 

 may be computed for a large number of points in the beam, and 

 then curves may be drawn showing the paths of the maximum 

 tensile and compressive stresses throughout the length of the 

 beam. 



Figure 12 & is a side view of a simple beam resting on two 

 supports, for which a number of the lines indicating the direc- 

 tions of the maximum tensile and compressive stresses have 

 been drawn. The lines of maximum compression are shown as 



