Page 93 - Mechanical Engineer's Data Handbook

82 MECHANICAL ENGINEER'S DATA HANDBOOK

"c w
where: R=- and r=-
W" a,
2Rr
Phase angle a = tan- -
(1 -r2)

5.0

b -
0 4.0
a -
.- c 3.0
.- 9 Frequency ratio, r= 0,
e
& 2.0
B Simple harmonic force applied to mass due to
rotary unbalance
1 .O
F = m,w2 cos ut (due to mass m, rotating at radius a
Frequency ratio r -
0 1 2 3 angular velocity u)
0, r2 2Rr
Q= ; a=tan-'-
J(1 -r2)2+4R2rZ (I-?)

r

Simple harmonic force of constant amplitude
applied to base

Fa = F COSO~
1 + 4R2rZ

I m