Inertia moment calculation
A-6
9
8
7
6
5
Apx
3
2
1
A
ppe
ndi
x
App
付
11
10
2
．
Inertia moment of cylinder
The moment of inertia of a cylinder
may be obtained from the graphs to
the right.
Apply the top graph to aluminum
materials (specific gravity: 2.7) and
bottom graph to steel materials
(specific gravity: 7.85):
(Example)
Material: Aluminum
Outer diameter: 100mm
Length: 7mm
Shape: Column
Because the outer diameter is
100mm, the radius is 50mm.
Therefore, the above graph gives
the inertia moment as follows:
Approximately 1.9 x 10
-4
kg
･
m
2
.
(Calculated value: 0.000186 kg
･
m
2
)
Radi
us
Lengt
h
1000
1000
100
10
1
0.1
0.01
0.001
10
-4
10
-5
10
-6
10
100
1000
20
30
50 70
200 300
500 700
Moment of inertia (Specific gravity 2.7)
Moment of inertia (kgm
2
)
Radius R(mm)
Length (mm)
1000
100
10
1
1000
100
10
1
0.1
0.01
0.001
10
-4
10
-5
10
-6
10
100
1000
20
30
50 70
200 300
500 700
Moment of inertia (Specific gravity 7.85)
Moment of inertia (kgm
2
)
Radius R (mm)
Length (mm)
1000
100
10
1
