1. Problem 1
3.3-9 Three identical circular disks A, B, and C are welded to the ends of three identical
solid circular bars (see figure). The bars lie in a common plane and the disks lie in planes
perpendicular to the axes of the bars. The bars are welded at their intersection D to form a
rigid connection. Each bar has diameter d1 = 0.5 in. and each disk has diameter d2 = 3.0 in.
Forces P1, P2, and P3 act on disks A, B, and C, respectively, thus subjecting the bars to
torsion. If P1 = 28 lb, what is the maximum shear stress tmax in any of the three bars?
R//tmax=4840 psi
Problem 2
A circular bar AB with ends fixed against rotation has a hole extending for half of its length
(see figure). The outer diameter of the bar is d2 = 3.0 in. and the diameter of the hole is
d1 = 2.4 in. The total length of the bar is L = 50 in. At what distance x from the left-hand
end of the bar should a torque T0 be applied so that the reactive torques at the supports will
be equal?
R// x=30.12in
2. Problem 3
Three solid shafts, each of 3/4-in. diameter, are connected by the gears as shown. Knowing
that G = 11.2 E6 psi, determine (a) the angle through which end A of shaft AB rotates, (b)
the angle through which end E of shaft EF rotates.
R//
∝ 𝐴= 24.5°
∝ 𝐸= 19.37°
