sm11 85

________________________________________________________________________
PROBLEM (11.85) An aluminum alloy 6061-T6 rod of diameter d supports a load P with
an eccentricity e (see Fig. P11.83). Employing the interaction method, with (σall )b = 22 ksi,
determine the longest length L that may be used.
Given: d = 2.5 in., P = 8 kips, e = 1in. ( σall )b = 22 ksi
SOLUTION
81 8 .
M
kip in=×= ⋅ , 22 4 (1.25) 4.91 . (1.25) 1.971 .
4
AinI 4 in
π
π == = =
4 0.625 .rIAd i=== n
Then
1
()()
all c all b
PA McI
σσ
+≤
33
3
8 10 4.91 8 10 (1.25) 1.917 1
( ) 22 10
all c
σ
××
+≤
×
or
3
1.629 10 0.237 1
()
all c
σ
×+≤, ( ) 2.14
all c ksi
σ
≥
Assume 66.
e
Lr Equation (11.29): >
22
51,000 51,000
() ; 2.14
() ()
all c ee
ksi
Lr Lr
σ ≤≤, 154.4 66
e
Lr
=
>
For ri 0.625 .n=
0.625 154.4, 96.5 .
ee e
Lr L L in== =
and
137.9 .
0.7
e
L
Li=== n
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.