Reference Guide

5-46 Equation Reference
Circular Ring (11, 5)
Equations:
A π ro
2
ri
2
–( )⋅=
I
π
4
---
ro
4
ri
4
–( )⋅=
J
π
2
---
ro
4
ri
4
–( )⋅=
Id I A d
2
⋅+=
Example:
Given: ro=4_ µ , ri=25.0 Å , d=.1_mil.
Solution: A=3.0631E–7_cm^2, I=1.7038E–10_mm^4, J=3.4076E–10_mm^4, Id=3.0648E–10_mm^4.
Triangle (11, 6)
Equations:
A
b h⋅
2
----------
=
P b v
2
h
2
+ b v–( )
2
h
2
++ +=
Ix
b h
3
⋅
36
-------------
=
Iy
b h⋅
36
----------
b
2
b– v⋅ v
2
+( )⋅=
J
b h⋅
36
----------
h
2
b
2
b– v⋅ v
2
+ +( )⋅=
Id Ix A d
2
⋅+=
Example:
Given: h=4.33012781892_in, v=2.5_in, P=15_in, d=2_in.
Solution: b=5.0000_in, Ix=11.2764_in^4, Iy=11.2764_in^4, J=22.5527_in^4, A=10.8253_in^2,
Id=54.5776_in^4.