-31-
or, in other words,
i / z M° Z ( j2 v3 vU p px Y 2 2
¿V ^ ( 1.25 - gl ♦ Y 2 * ♦ y j
2[X 2 Y 2 xU+ y U
+ Cl 2 B*“
&V- 5 ig»!>
(75)
Substituting N for X/B and taking into consideration that Y/B = 1.25,
equation (75) could be modified as follows:
Z ~7 Z
flp= Mff-(U.39 +3.9N +5.lS3N 2 -0.625N 3 +0.8125^+0.5859^) • ^
.Z-,2.
_ (U.39 +3.9N +^.l53N 2 -0.62^N 3 +0.8l2^+0.5855^>.
t Z*
In equation (76) the term 0.8125 dominates the other terms as
soon as N gets larger than 5. In the case of N=11 for example, the
effect of all the other terms combined will be just 0.8$ of the effect
of the tern 0.8125N (for f=3 in., Z=0.674y, for f=12 in., Z=2.67Y).
Equation (76) could then be modified to read:
In other words, we will have:
/^P = -^-(0.8l25N*).
(77)
jU p =1^(0.90I4N*)
(78)
Considering a bridged distance of length X and spanning N models,
j~ip in the middle of the bridged distance (corresponding to N/2
models) could be given as:
^P„ = i T^(0-2254N Z ).
(79)
At the end of the bridged distance ^Xp would then be 2^Up :
=
f
N •
0.45
(80)