Vibration Suppression of Grass Trimmer Handle using Tunable Vibration Absorber

The electrical grass trimmers are widely used for cutting grass along the highways, roadside & general agricultural work. Grass trimming involves the use of motorized cutter spinning at high speed, resulting in hand-arm vibration syndrome among the machine operators. The purpose of this work is to reduce the handle vibration of grass trimmer using tuned vibration absorber (TVA). The variable stiffness dual mass vibration absorber is designed using Dunkerleys Equation and fabricated for testing. The experimental modal analysis of absorber is conducted to find resonance frequencies of the absorber and to validate the results obtained from equations. The experimental tests are carried on grass trimmer with absorber attached at different location for two cutter head positions to find the absorber attachment location to reduce handle vibrations to minimum level. The results indicated that the vibration attenuation is affected by the location of absorber and cutter head position of grass trimmer.