As shown, a curtain wall is constructed of brick masonry (a = 0.000 005 in/in-°F). The bot...

As shown, a curtain wall is constructed of brick masonry (a = 0.000 005 in/in-°F). The bottom of the masonry wall bears on the leg of a steel angle that is welded to and extends from a steel spandrel beam at each floor. The wall extends to the bottom side of the leg of a steel angle on the upper floor. The wall measures 12.0 ft and is fully restrained between the angles. It is installed at a temperature of 55°F. On a hot summer day, the temperature of the wall can rise to 90°F. In the winter, the temperature of the wall can fall to 20°F. Stress due to weight of the wall is 15 lb/in2 at the base of the wall (at the bearing point on the angle).

(a) Determine the maximum thermal stress that develops in the curtain wall.

(b) Determine the maximum stress that develops in the curtain wall with this temperature change.