Page 70 - DJJ 40173 compile notes - E-BOOK NEW EDIT WITH INDEX_Neat
P. 70

Direct stress in the round bar








      ◦ Figure below shows a bar of constant cross-sectional

         area A. The end of the bar carry uniformly distributed
         normal loads of intensity p. We know from static that:






             when the loading is uniform, its resultant passes through
             the centroid of the loaded area





      ◦ Therefore the resultant P=Σp of each end load acts                                                                     P
         along the central axis of the bar. In the case of                                                           p                 Area= A

         uniform loading the internal forces acting on all cross

         sections are also uniformly distributed.


                                                                                                                      p

      ◦ Therefore, the normal stress acting in any point on a

         cross section is


                                                 σ  =      

                                                           
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