고체역학 (Gere) — Axially Loaded Members: Problem 2.5-15

2.5-15 A rigid triangular frame is pivoted at C and held by two identical horizontal wires at points A and B (see figure). Each wire has an axial rigidity \(EA = 540\text{ kN}\) and coefficient of thermal expansion \(\alpha = 23 \times 10^{-6}/^\circ\text{C}\). (a) If a vertical load \(P = 2.2\text{ kN}\) acts at point D, what are the tensile forces \(T_A\) and \(T_B\) in the wires at A and B, respectively? (b) If both wires have their temperatures raised by \(100^\circ\text{C}\) while the load \(P\) is acting, what are the forces \(T_A\) and \(T_B\)? (c) What further increase in temperature will cause the wire at B to become slack?