Page 81 - Civil Engineering Formulas
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BEAM FORMULAS                    37

                          l
                    x         W
                                        R = V         =  W
               R                   R                     2
                     l        l         V when x <  l  =  W  (l  – 4x )
                                                            2
                                                                 2
                                         x
                     2       2                    2     2l 2
              V                         M max (at center)  =  Wl
                                                         6
                                                   l        1   2x 2
                    Shear           V   M when x <    = Wx    –
                                         x
                                                   2        2   3l 2
                                        Δ max  (at center)  =  Wl 3
                                                        60EI
             M max                                        Wx
                                        Δ x           =  480EIl 2 (5l  – 4x )
                                                                    2 2
                                                                2
                       Moment
                                         (n)
             FIGURE 2.3 Elastic-curve equations for prismatic beams: (n) Simple beam—load
             increasing uniformly to center. (Continued)



                                                       wa
                                          = V        =    (2l – a)
                         l              R 1  1max       2l
                     a                                 wa 2
                    wa                  R = V 2      =
                                         2
                                                        2l
                                        V (when x < a)  =  R – wx
                                                        1
               R 1                  R 2                  2
                                        M    at x  =  R 1  =  R 1
                    x                     max     w    2w     2
                                        M  (when x < a)  =  R 1 x –  wx
                                          x
              V 1                                            2
                                                         (l – x)
                    R 1                 M x  (when x > a)  =  R 2 wx
                                                             2
                    W      Shear   V 2  Δ  (when x < a)  =  24EIl  [a (2l – a) 2
                                         x
                                                           2
                                                                     3
                                                       – 2ax (2l – a)+ lx ]
             M max
                                                         2
                                                       wa (l – x)
                                        Δ x  (when x > a)  =
                                                         24EIl
                       Moment                                2   2
                                                       (4xl – 2x  – a )
                                        (o)
             FIGURE 2.3  Elastic-curve equations for prismatic beams: (o) Simple beam—uniform
             load partially distributed at one end. (Continued)
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