62
Figure 2.9
Stress
on ~
141 ksi
Chapter 2
156 ksi
Structural member t =-3 and R = 0.999.
From the Example 2.14 and Eqs. (2.25) and (2.26)
rma x
= 3(0.005?) + ? = 1.015
Pmax= 6000 lb + 3(90 lb) = 6270
Pmin= 60001b - 3(901b) = 57301b
Notes:
I. If P is Pmax or Pmin it also applies in both numerator and
denominator. In other words one cannot use Prn.× in the numerator and Pmin in the denominator.
The same can be said for rmax and rmin as for Pmax and Pmin.
However since the calculation is to find O’ma x and O’mi n the following
are valid statements
Pmax
O’max -- 2
/l~/*rnin
Pmin
°’rain
/l~r2max
rm~n = --3(0.005?) + ? = 0.985?
Substituting
6270 lb
2057.05
tYmax ~[0.985712
72
57301b
1770.41
O’min ~[0.985712
?2
Figure 2.9
Stress
on ~
141 ksi
Chapter 2
156 ksi
Structural member t =-3 and R = 0.999.
From the Example 2.14 and Eqs. (2.25) and (2.26)
rma x
= 3(0.005?) + ? = 1.015
Pmax= 6000 lb + 3(90 lb) = 6270
Pmin= 60001b - 3(901b) = 57301b
Notes:
I. If P is Pmax or Pmin it also applies in both numerator and
denominator. In other words one cannot use Prn.× in the numerator and Pmin in the denominator.
The same can be said for rmax and rmin as for Pmax and Pmin.
However since the calculation is to find O’ma x and O’mi n the following
are valid statements
Pmax
O’max -- 2
/l~/*rnin
Pmin
°’rain
/l~r2max
rm~n = --3(0.005?) + ? = 0.985?
Substituting
6270 lb
2057.05
tYmax ~[0.985712
72
57301b
1770.41
O’min ~[0.985712
?2