A built-up beam supporting a condominium balcony is made up of a structural T (one half of a W 200 x 31.3) for the top flange and web and two angles (2L 102 x 76 x 6.4, long legs back-to-back) for the bottom flange and web, as shown. The beam is subjected to a bending moment M having its vector at an angle u to the z axis (see figure).
Determine the orientation of the neutral axis and calculate the maximum tensile stress st and maximum compressive stress sc in the beam. Assume that θ = 30° and M = 15 kN m. Use the following numerical properties: c1 = 4.111 mm, c2 = 4.169 mm, bf = 134 mm, Ls = 76 mm, A = 4144 mm2, Iy = 3.88 x 106 mm4, and Iz = 34.18 x 106 mm4.

Transcribed Image Text:

C1 Ls L