Estimating the Damping in a Single Degree of Freedom System - Lab Report Example

There are a number of sources for damping and in this experiment; we are required to determine their overall effect. The excitation of the system will be provided by a shaker driving the opposite end of the beam from the attached weight. Two different methods will be used to estimate the damping: half-power bandwidth measurement in the frequency domain and a logarithmic decrement in the time-domain. a) Set up the system to use an accelerometer to measure the vibration of the beam near the attached weight while applying a computer-generated forcing signal via the shaker attached to the opposite end of the beam. c) Observe the resonant peak corresponding to mass-on-a-spring type motion, and compare it to what you would expect based on a simple calculation using the mass of the attached weight and the static stiffness of the beam.

When a mechanical system is displaced from its position at equilibrium and then released, the restoring force returns it to equilibrium position. This kind of movement is referred to as free vibration. Free vibration results arise from the initial impact energy that keeps changing consistently from potential energy to kinetic energy forms. In a state of free vibration, the mechanical system is said to be vibrating at its natural frequency. However, due to some various causes, dissipation of the mechanical energy occurs during vibration and this effect is referred to as damping.

In theory, an un-damped freely vibrating system continues to vibrate after it has started. In this experiment, we shall investigate the effect of damping and the level of damping in the mechanical system. Vibration can basically be classified in a number of ways including: b. Un-damped and damped vibration: In un-damped vibrations, no energy is lost or dissipated as a result of friction during the oscillatory motion. If any energy is lost, the