Lecture 12 System Models Part 2

Question 1

When mass elements are rigidly connected together equivalent mass for translational motion is

Answer 1

sum of the masses

meq = m1 + m2 + m3

Question 2

Rigid connection for inertia,

rigidly connected together for rotation about a point

Answer 2

J0 = (JG1 + m1r1^2) + (JG2 + m1r2^2) + (JG3 + m1*r3^2)

Question 3

Equivalent translational mass meq =

Answer 3

m + J0/R^2

Question 4

Equivalent Rotation Inertia Jeq =

Answer 4

Jeq = mR^2 + J0

Question 5

Equivalent kinetic energy equation =

Answer 5

T = sum 1/2 mx.^2 + sum 1/2 Jtheta.^2

where theta. = x./R

Question 6

velocity at contact is

Answer 6

the same for both wheels therefore

v = wa * ra = wb * rb

Question 7

What happens to a deformed shape at resonance

Answer 7

dominated by a specific mode with own stiffness and damping depending on the shape

Question 8

Energy dissipated in damper

Answer 8

delta W = pi() * c * w * X^2

Question 9

Method for equivalent damper

Answer 9

use delta W = pi() * c * w * X^2, and related X^2 for each damper using similar triangles