Abstract
The transmission of vibrations from hand-held impact machines (HHIM) to the human hands is undesirable and can cause serious injury, including amputation of the hand. Therefore, it is crucial to analyze and develop efficient vibration control methods to curb vibration transmission to the hands from a HHIM. The first step towards developing an efficient vibration control method is to obtain a model that can accurately predict the dynamics of the HHIM. Thereafter, a numerical or theoretical study of the HHIM-Vibration control device model can reveal the devices effectiveness. To address the need for a HHIM model, we analyze a reduced order model of a HHIM which incorporates the vibro-impact interactions of the HHIM bit with the ground. The effectiveness of a cubic nonlinear absorber in the HHIM is then studied via a lumped mass parameter model consisting of a vibro-impact tool model coupled to the hand-arm system (HAS) and a cubic nonlinear tuned vibration absorber (NLTVA). A detailed numerical analysis of this system is performed to show the rich nonlinear dynamics of the system. The results from this study show that an appropriate selection of absorber parameters can effectively change the amplitude and periodicity of vibrations at the hand, thereby proving the potential of a cubic nonlinear absorber as a viable vibration control option.
