고체역학 (Gere) — Stresses in Beams (Basic Topics): Problem 5.5-13

5.5-13 A fiberglass pipe is lifted by a sling, as shown in the figure. The outer diameter of the pipe is 150 mm, its thickness is 6 mm, and its weight density is \( 18 \text{ kN/m}^3 \). The length of the pipe is \( L = 13 \text{ m} \) and the distance between lifting points is \( s = 4 \text{ m} \). (a) Determine the maximum bending stress in the pipe due to its own weight. (b) Find the spacing \( s \) between lift points which minimizes the bending stress. What is the minimum bending stress? (c) What spacing \( s \) leads to maximum bending stress? What is that stress?