Efficacy of a Sliding Beam as a Nonlinear Vibration Isolator

The influence of friction due to beam sliding at its supports on its dynamic behavior and its efficacy as a nonlinear isolator is studied numerically under sinusoidal and random excitation excitations. Under sinusoidal excitation, the equation of motion of the system is solved numerically and the solution is utilized to estimate the system transmissibility. It is found that when the excitation frequency is increased beyond resonance, the friction at the sliding supports serves to improve the transmissibility. The dependence of the response on initial conditions establishes the basins of attraction for different values of friction coefficient and excitation frequency and amplitude. Under random excitation, the system response statistics are estimated from Monte Carlo simulation results for different values of friction coefficient and excitation power spectral density level. The friction is found to result in a significant reduction of the system response mean square.