11.1.1. Physical Considerations
Vibration is the oscillatory motion of objects. Several different measurable parameters may be of interest: relative position, velocity, acceleration, jerk (the derivative of acceleration), and dynamic force are those most generally desired.
For each parameter it may be the instantaneous value, the average value, or some other descriptor that is needed. Accuracy on the order of 1 part in 100 is generally all that is called for.
Vibration, in the general sense, occurs as periodic oscillation, as random motion, or as transient motion, the latter more normally being referred to as shock when the transient is large in amplitude and brief in duration.
Vibration can occur ...