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ART. 6. WEB PLATES 



The maximum stresse- that the web nf a beam or 

 girder must resfarf an- of varying intensity and direction 

 throughout r 



For any elementary parallelepiped cut from tin- body 

 of a beam in equilibrium subject to ftVxuiv. tin- foicos on 

 the faces of tin- < -1< -ment perpendicular to the plan. <>f 

 the drawing may be represented for the most general case 



irfr 



FIG. 6a. 



as shown. The weight of the elementary particle may be 

 neglected, as it is an infinitesimal of the third order as 

 compared with the amount of stress on the faces, which 

 are infinitesimals of the second order. 



As the length of the sides of the particle approach 

 lero as a limit, the intensities of the oppositely directed 

 forces p w are equal, and also the forces p z . If the opposit < 1 \ 

 dir.-ctcd normal forces are of equal intensity the tan- 

 gential or shearing forces q are also of equal intensity. 

 The intensity of the shearing stresses at any point in a 

 homogeneous prismatic body subject to flexure is gi\< n 



