Effect of Attachment Configuration on Impact Vibration Absorbers

A zero-to-peak amplitude of excitation (mm) r frequency ratio ( = f/fn) c damping coefficient (kg/s) t time (s) D clearance (impact mass to impact walls) (mm) x deflection of primary mass (mm) f frequency of vibration, excitation frequency (Hz) xw system response amplitude with IVA (mm) fn natural frequency (Hz) xwo system response amplitude without IVA (mm) k spring constant (N/m) y base excitation l length of leaf beams (mm) H initial displacement (micro strains) L length of pendulum (mm) T angle of rotation of pendulum (degrees) m1 mass of primary mass (kg) P mass ratio ( = m2/m1) m2 mass of impact vibration absorber (kg) This experimental research deals with passive vibration control of a primary mass using an impact vibration absorber (IVA). This paper is on two types of IVAs, namely, a simple IVA and a compound IVA, which have different attachment configurations for the impacting mass. The primary objective of this research was to compare the absorption characteristics of simple and compound IVAs in case of transient and forced vibration. The secondary objective was to determine the effect of system parameters on the absorption efficiency of a compound IVA for both transient and forced vibration. For transient vibration involving the compound IVA it was shown that the longest pendulum was more efficient than the shortest pendulum. The largest clearance was more efficient than the smallest clearance. For the largest initial displacement the vibrations were attenuated faster than for the smallest initial displacement. For forced vibrations, the simple IVA (compared to the compound IVA) has more pronounced inefficient absorption region. This is due to the apparent shift of the resonance point. On the other hand the compound IVA hardly has a clear inefficient absorption region. In the respective absorption region, it is noted that the simple IVA has a more prominent vibration absorption level