A post having a hollow, circular cross section supports a P = 3.2 kN load acting at the end of an arm that is b = 1.5 m long (see figure). The height of the post is L = 9 m, and its section modulus is S = 2.65 X 10⁵ mm3. Assume that the outer radius of the post is r₂ = 123 mm, and the inner radius is r₁ = 117 mm.

(a) Calculate the maximum tensile stress σ_max and maximum in-plane shear stress t max at point A on the outer surface of the post along the x-axis due to the load P. Load P acts at B along line BC.

(b) If the maximum tensile stress and maximum in-plane shear stress at point A are limited to 90MPa and 38 MPa, respectively, what is the largest permissible value of the load P?

Transcribed Image Text:

9 m X Z 1.5 m. A B P C (-3.2 m, 2.5 m, 0)