Popis: |
Due to the severity of vibrations transmitted to a worker’s hand through hand-help impact machines (HHIM), workers often suffer from hand-arm vibration syndrome (HAVS). Symptoms of HAVS include vibration white fingers, finger numbness, impaired tactile function, and muscle fatigue. To attenuate the level of transmitted vibrations and, hence, reduce the severity of HAVS, a method of using a nonlinear vibration absorber inerter (NVAI) has been proposed recently. It was observed that the use of NVAI can significantly reduce the transmitted vibration. However, a detailed nonlinear analysis of the HHIM with NVAI has not been performed, which can further help in the optimum design of the NVAI. This is the focus of the current work. The hand-arm system (HAS) coupled to an HHIM with an NVAI is modeled using a lumped parameter model. A detailed nonlinear analysis is performed numerically. A parametric study is performed to explore the effects of different system parameters on the system dynamic and identify key design parameters of the NVAI. We observe that the system exhibits quasi-periodic and periodic motion, which is further confirmed by Poincare maps and Phase portraits. It is further revealed that a careful selection of the absorber properties can significantly reduce harmful vibrations. |