Optimum Design
163
ROUND SPRI NG
Figure 3.4 Torsional spring cross section.
(a) Criterion function
Wspring = 2~rRtLy
(b)
There are now four functional constraints
Torsional frequency constraint [3.5]
f - 2re 2rr V Ip
from torsion
TL
GJ
T
GJ
0
L
where for thin wall tube the area moment of inertia is
J = 2~R3t
The lp is the mass moment of inertia
mR 2
Ip -- 11.6436 × 10 -3 m- lb. sec
2
g 2
(3.49)
163
ROUND SPRI NG
Figure 3.4 Torsional spring cross section.
(a) Criterion function
Wspring = 2~rRtLy
(b)
There are now four functional constraints
Torsional frequency constraint [3.5]
f - 2re 2rr V Ip
from torsion
TL
GJ
T
GJ
0
L
where for thin wall tube the area moment of inertia is
J = 2~R3t
The lp is the mass moment of inertia
mR 2
Ip -- 11.6436 × 10 -3 m- lb. sec
2
g 2
(3.49)