________________________________________________________________________
PROBLEM (11.74) Select the minimum width a of a square timber column of effective
length Le = 4 m if it must support an axial load P = 200 kN.
Given: E = 12 GPa, σall = 9 MPa
SOLUTION
Use Eq. (11.32):
2
0.3
()
all e
PE
ALd
σ
==
or
d=a
39
22
200 10 0.3(12 10 )
(4 )aa
××
=
Solving,
44
16 1.8 10 , 172.7aa=× =mm
Check :
3
2
200 10 6.71 9
(0.1727)
M
Pa MPa
σ
×
==<
Use
173am=m
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