10 THIS AND THE FOLLOWING PROBLEM MAY BE THE STUDENT’S FIRST EXPERIE...

1-10 This and the following problem may be the student’s first experience with a figure of merit.

• Formulate fom to reflect larger figure of merit for larger merit.

• Use a maximization optimization algorithm. When one gets into computer implementa-

tion and answers are not known, minimizing instead of maximizing is the largest error

one can make.

F V = F 1 sin θW = 0

F H = − F 1 cos θF 2 = 0

From which

F 1 = W / sin θ

F 2 = − W cos θ/ sin θ

fom = − S = − ¢ γ (volume)

= − . ¢ γ (l 1 A 1 + l 2 A 2 )

A 1 = F 1

S = W

S sin θ , l 2 = l 1

cos θ

= W cos θ

F 2

A 2 =

S

S sin θ

l 2

W

fom = − ¢ γ

S sin θ + l 2 W cos θ

1 + cos 2 θ

= − ¢ γ W l 2

cos θ sin θ

Set leading constant to unity

θ fom

θ * = 54 . 736 Ans.

0 −∞

fom* = − 2 . 828

20 − 5.86

Alternative:

30 − 4.04

40 − 3.22

d

= 0

45 − 3.00

d θ

50 − 2.87

And solve resulting tran-