Telechargé par Gingermon

sm9 2

publicité
_______________________________________________________________________
PROBLEM (9.2) A hollow outboard motor propeller shaft with an outer diameter D and inner
diameter d is simultaneously acted upon by a torque T and an axial thrust P (Fig. P9.1) . What is the
maximum shearing stress in the shaft?
Given: D = 8 in.
d = 4 in.
T = 400 kip ⋅ in. P = 250 kips
SOLUTION
A=
π
4
(82 − 42 ) = 37.7 in.2
J=
π
32
(84 − 44 ) = 377 in.4
P
250
=−
= −6.63 ksi
37.7
A
Tr 400(4)
τ xy = =
= 4.24 ksi
377
J
Thus
σx = −
τ max = (
σx
2
τ xy
σx
) 2 + τ xy2
= (−3.315) 2 + (4.24) 2 = 5.38 ksi
Excerpts from this work may be reproduced by instructors for distribution on a not-for-profit basis for testing or
instructional purposes only to students enrolled in courses for which the textbook has been adopted. Any other
reproduction or translation of this work beyond that permitted by Sections 107 or 108 of the 1976 United States
Copyright Act without the permission of the copyright owner is unlawful.
Téléchargement