Telechargé par Gingermon

sm11 66

publicité
________________________________________________________________________
PROBLEM (11.66) Redo Prob. 11.65, assuming that the column is pinned at one end and
fixed at the other.
SOLUTION
Le = 0.7 L = 420 mm ,
Le r = 0.42 (a 2 3) = 1.455 a
Assume: 9.5 < Le r < 66. Equation (13.21):
σ all =
250 ×103
1.455
= [140 − 0.87(
)]106
2
a
a
or
a 2 − 9.04 ×10−3 a − 1.786 ×10−3 = 0
Solving: a = 47.02 mm. So,
r = a 2 3 = 13.57 mm
Le r = 420 13.57 = 30.95 < 66
Our assumption was correct. Use a = 47 mm
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