Page 72 - Civil Engineering Formulas
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R 2                 k(1 – k 2 )
                                          3  2  PL 2  6EI  kx″(1 – k 2 – x″ 2 )
                R 2 = Pk         x″L  (x″ < (1 – k))  R 2 x″ L  1 – k 2  k  3  1 – k 2  3
            (l – k)L                      PL 3  =  3EI  PL 3  6EI  L

                    Load     Shear      Moment  d max  Elastic curve  (c)
                  L
           P                        k(1 – k)PL                simply supported prismatic beam. (c) Shears, moments,
                R 1 = (l – k)P
             1  2                         k 2 (1 – k) 2  (1 – k)x′(2k – k 2 – x′ 2 )
            kL
             k <                x′L  (x′ < k)  R 1 x′ L  PL 3  3EI  k(1 – k)(2 – k)
                        R 1                        PL 3  6EI
                                                PL 2  6EI
                              R 2
                   (2c + b)                  (x″ < c)  x″   Elastic-curve equations for prismatic beams: (a) Shears, moments, and deflections for full uniform load on a simply sup-

            c
                  wb  2L                           R 2 x″
                   R 2 =  R 1 – w (x – a)       R 2c

          L          Load          Shear     1  2w  1  R (a +  Moment  (b)
            b                                 R  2  1
                   (2c + b)      R 1  w    2  (x – a)  w  R 1a  –  R x
              w   wb  2L      x  (a < x < a + b)  a +  R 1 x′
            a
                   R =                       (x′ < a)  x′      and deflections for a concentrated load at any point of a simply supported prismatic beam.
                           R 1                                ported prismatic beam. (b) Shears and moments for uniform load over part of a

                                  R
                        wL  2
                        R =
                                    L  2   wL 2  8
                              – xwL               5wL 4  384EI  Elastic curve
                          Load        Shear   Moment  L  c
                  L          1  2                        (a)
                    w
                                                     wL 4  24EI
                                    1  2
                        wL  2    xL 1  2
                        R =        x <   x(l – x)wL 2  x(l – 2x 2  + x 3 )  FIGURE 2.3
                               R        1  2   wL 3  24EI





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