REAL STRESS DIAGRAMS. 



161 



curves. An example of this is given on Fig-. 76. The 

 construction will be clear from the diagram. 

 Here 



L = the original length of the specimen. 

 I = the compression or shortening. 

 A = the original area. 

 a = the area at the point in question. 



Inches 



2.5 



c 



2.0 



B 



1.6 

 1.0 



C/JO.6 



' 





^E 



\ 



)Q 2O 30 4O 



Uoads 



FIG. 76. 



Tons. 



The volume being supposed to be constant, and the 

 specimen to have kept its parallel shape, 



AxL 



A 



a 



M2 



= ax(L I) 



L-l 

 L 



GB 

 " GC 



