PROBLEM 10.58
Two solid steel shafts are fitted with flanges that are then
connected by bolts as shown. The bolts are slightly
undersized and permit a 1.5° rotation of one flange with
respect to the other before the flanges begin to rotate as a
single unit. Knowing that G = 77.2 GPa, determine the
maximum shearing stress in each shaft when a torque of T
of magnitude 500 N ⋅ m is applied to the flange indicated.
The torque T is applied to flange B.
SOLUTION
Shaft AB:
4 4 94
99
3
1
, 0.6 m, 0.015 m
2
(0.015) 79.522 10 m
22
(77.2 10 )(79.522 10 )
0.6
10.2318 10
ππ
ϕ
ϕϕ
ϕ
−
−
= = = =
= = = ×
=
××
= =
= ×
AB
AB
AB AB
BAB AB
AB AB
AB B B
B
TT L c d
Jc
TL
GJ
GJ
TL
Shaft CD:
44
94
99 3
1
, 0.9 m, 0.018 m, (0.018)
2 22
164.896 10 m
77.2 10 )(164.896 10 ) 14.1444 10
0.9
ππ
ϕ ϕϕ
−
−
= = = = = =
= ×
(× ×
= = = ×
CD CD CD
CD
CD CD
CD C C C
CD
TT L c d J c
J
GJ
TL
Clearance rotation for flange B:
3
1.5 26.178 10 rad
B
ϕ
−
′= °= ×
Torque to remove clearance:
33
(10.2318 10 )(26.178 10 ) 267.85 N m
AB
T
−−
′= × ×= ⋅
Torque
to cause additional rotation
: 500 267.85 232.15 N mT
ϕ
′′ ′′ =−= ⋅
33 3
232.15 (10.2318 10 14.1444 10 ) 9.5236 10 rad
ϕϕ
−
′′ ′′
= ×+ × ∴ = ×
33
33
(10.2318 10 )(9.5236 10 ) 97.444 N m
AB
T
−
−
′′ = × ×= ⋅