Vibration neutralizers provide an effective method of attenuating tonal vibrations within a structure. In this paper, variable stiffness vibration neutralizers are used to impose zero displacement or nodes to reduce vibration at desired locations on a Euler-Bernoulli beam subjected to forced harmonic excitation. An iterative procedure is developed to find the required resonance frequencies of neutralizers to create nodes at selected locations. Numerical tests are performed to show the viability of the procedure that is developed. Experimental tests are conducted and results are compared with those obtained by numerical tests.

In this paper, variable stiffness damped absorbers are used to isolate the substructures of Euler-Bernoulli beam, modelled as lumped masses, from vibrations. The novel algorithm is developed that can be used to determine the required absorber masses and resonance frequencies to impose nodes at selected locations on beam with the constraint of vibration amplitude of absorber mass. Numerical simulations are performed to show the effectiveness of the proposed algorithm. Experimental test is conducted on a cantilever beam with two absorbers to verify the numerical results.

The purpose of this investigation is to apply imposing node technique for vibration reduction of petrol engine grass trimmer handle using vibration absorber. The algorithm is devised to find the required resonance frequency of the absorber to impose node at desired location on beam. The numerical simulations are performed to find the usefulness of absorber for imposing nodes at the handle attachment location on timer pipe. The experimental test is conducted to validate the numerical results and to evaluate the vibration suppression during no cutting and cutting conditions. The vibration total value measured at handle of grass trimmer shows that absorber is useful in handle vibration reduction.

In this investigation, the novel multi-axial vibration absorber is proposed to reduce the handle vibration of petrol engine grass trimmer. The proposed vibration absorber is designed using Dunkerley’s 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 near handle location to find effectiveness of absorber in reducing hand-arm vibrations in the x, y and z directions. The result indicated that the total vibration value measured at the handle of grass trimmer is reduced by substantial level with the attachment of multi-axial vibration absorber.

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