Development of Inerter Enhanced Tuned Mass Damper in Grass Trimmer

Tiew, Xing Let (2023) Development of Inerter Enhanced Tuned Mass Damper in Grass Trimmer. Final Year Project (Bachelor), Tunku Abdul Rahman University of Management and Technology.

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Abstract

Prolonged exposure to high vibration level will cause the development of a detrimental health condition called the hand-armvibration syndrome (HAVS). Despite the negative consequences, the exposure to hand-arm vibration above the daily exposure limit is still considerably high, resulting in high risk of HAVS development. The high exposure to hand-arm vibration is especially true for the grass trimmer users. In recent studies, numerous methods have been explored to mitigating the vibration of the grass trimmer. The application of tuned mass damper is commonly explored to reduce the vibration. Despite that, due to the wide frequency band of the grass trimmer, the tuned mass damper often only functions effectively at the specify frequency. In recent year, the passive vibration component, the inerter has gain much popularity especially in vibration mitigation in the transport and civil industry. Based on its beneficial properties, the passive vibration suppression with reduce mass and across a wide frequency band can be achieve. In the literature review, the HAVof grass trimmers and some proposed solutions have been examined. Furthermore, the inerter and its application in other areas are also reviewed. In the present study, the mathematical model of the grass trimmer is developed, along with models with tuned mass damper and inerter enhanced tuned mass damper. Based on the respective governing equations, the suitable parameters of the tuned mass damper is determined. Then, the performance of the models are compared through the magnification factor against forced frequency ratio graph. A total of five models are evaluate, these models are the tuned mass damper model, the inerter enhanced model with inertance ratio of 1% , the inerter enhanced model with inertance ratio of 0.02%, the inerter enhanced model based on literature and the proposed inerter enhanced model. The results shows that all models successfully reduced the vibration but the tuned mass damper model reduced the most at 75.51%. In addition, all the models are ineffective across the operating frequency range beside the literature based model and the proposed model. The guide on selection and tuning of the tuned mass damper based on the operating frequency is then present.