Chapter 8, Reserve Problem 045 (GO Tutorial) A beam having a tee-shaped cross section is subjected to equal 13 kN-m bending moments, as shown. Assume b = 95 mm, ty = 25 mm, d = 165 mm, tw = 40 mm. The cross-sectional dimensions of the beam are also shown. Determine (a) the centroid location (measured upward from the bottom), the moment of inertia about the z axis, and the controlling section modulus about the z axis. (b) the bending stress at point H (positive if tensile and negative if compressive). (c) the maximum bending stress (positive if tensile and negative if compressive) produced in the cross section. Cross section Answers: (a) y = mm I: = |(105) mm4 S= (10) mm3 (b) GH = MPa (c) Omax = MPa

A beam is subjected to equal 21.7 kip-ft bending moments. Assume t₁ =t₂ = tw- 3 in., d = 15 in., b₁ = 6 in., and b₂ =8 in. The cross- sectional dimensions of the beam are illustrated. Determine: (a) the distance y to the centroid (measured from the bottom), the moment of inertial₂ about the z axis, and the controlling section modulus S₂ about the z axis. (b) the bending stress at point H (positive if tension, negative if compression). (c) the bending stress ok at point K(positive if tension, negative if compression). (d) the maximum bending stress max produced in the cross section (positive if tension, negative if compression). M Answers: (a) y = (b) 6μ = 6.978 (c) OK (c) omax = = i M in., I₂ = X i psi. psi. psi. 41 1₂ 2886.59 b₁ b₂ Cross section H K in.4, S₂ = i in.³.