Numerical Modelling and Experimental Investigation of a Single and a Compound Pendulum Impact Dynamic Vibration Absorbers

This paper deals with vibration reduction of a mechanical vibrating system using passive impact vibration absorber (IVA). The damping potentials of a single mass IVA (SIVA) and a compound pendulum IVA (PIVA) are studied. The numerical and the experimental investigations are carried in free vibration modes. The influence of the IVA’s configuration parameters such as the mass ratio, restitution coefficient, clearance, and the pendulum length on the vibration reduction for the main system were studied. A single degree of freedom (SDOF) oscillator equipped with a PIVA is designed and fabricated to conduct the experimental tests. The results show that the efficiency of the IVA depends mostly on the number of effective collisions rather than the aggregate number of impacts. The IVA’s clearance and the mass ratio are important design parameters for the SIVA. In addition, to the pendulum length for the PIVA. A good combination of these design parameters accomplishes the higher vibration suppression capacity. The results demonstrate that it is recommended to take the IVA's mass ratio lying around 0.1. In addition, low or high values of the restitution coefficient do not improve the damping capacity. Moreover, it is recommended to select the relative clearance between 0.4 and 0.6 for the SIVA and between 1.3 to 1.5 with frequency ratio around 0.4 for the PIVA to maximize damping. The PIVA with suitable parameters can attenuate vibrations much better than SIVA by about 50%.