Page 74 - Fundamental Of Design In Mechanical Engineering
P. 74

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

         uniform loading the internal forces acting on all cross                                                                    Area= A

         sections are also uniformly distributed.


                                                                                                                      p

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

         cross section is


                                                 σ  =                                                                               74

                                                           
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