Web (vertical section of cross-section): • du = 340 mm • t = 15 mm The loading of the beam can be modelled as the following free-body diagram, where P = 20 kN represents the dead load of each wall, and w = 4 kN/m represents the dead load of the flooring uniformly distributed over the span of the beam P t W L The Young's moduli of each material may be given by: • Steel: E, 200 GPa • Timber: E = 25 GPa The length of the beam is L= 8 m. The engineer will consider the stresses developed at the mid-span of the beam. The following beams will be considered: 1. all timber (flange + web), 2. a composite beam consisting of a steel flange and timber web, and a composite beam consisting of a timber flange and steel web. In all cases, assume both materials remain linear elastic under the loading. P 1.B. kN (assume upwards is positive) Bending Moment at Mid-Span of Beam For this problem, the engineer in interested in determining the stresses in the beam at its "mid-span" (i.e. halfway along its length). By first calculating the reactions on the beam, what is the internal bending moment within the beam at the "mid-span"? kN (assume upwards is positive) Ay = By= Bending moment at mid-span of beam: M₂ L/2 kNm Use this value of internal bending moment in the calculations to come for stress.