고체역학 (Gere) — Axially Loaded Members: Problem 2.6-4

2.6-4 A brass wire of diameter \( d = 2.42 \text{ mm} \) is stretched tightly between rigid supports so that the tensile force is \( T = 98 \text{ N} \) (see figure). The coefficient of thermal expansion for the wire is \( 19.5 \times 10^{-6}/^{\circ}\text{C} \), and the modulus of elasticity is \( E = 110 \text{ GPa} \). (a) What is the maximum permissible temperature drop \( \Delta T \) if the allowable shear stress in the wire is \( 60 \text{ MPa} \)? (b) At what temperature change does the wire go slack?