Maximum bending moment at P:

For the beam in Figure if a uniformly distributed load (udl) of 3 kN/m longer than the span crosses it from left to right, what will be the maximum bending moment at P?

Solution

In Figure 5, it can be seen that as the influence line diagram for bending moment at P (MP) is positive over the whole span AB, the moving udl has to cover the entire span for maximum value.

Hence, by Property (d) of the IL Diagram as stated above the maximum

MP = (Intensity of loading) × (Area of IL Diagram)

= 3 ×  (1/2 × 2.4 × 10 ) = 36 kNm .