Suppression of structural vibration with a new type of vibration absorber

Abstract

A new type of dynamic vibration absorber (DVA) has been designed to be the combination of different types of vibration absorbers attaching at a single point, which, was proposed and evaluated for vibration suppression. The effects of a number of absorber parameters and locations of attachment have been compared. Holographic full-field vibration visualization techniques have been tried for finding a suitable location of absorber on the controlled structure. Basic theories of the new dynamic absorber in suppression of vibration have been established. The suppression of harmonic vibrations of a single-degree-of-freedom (SDOF), multi-degree-of-freedom (MDOF) discrete system and continuous systems such as beams and plates by the proposed dynamic vibration absorbers have been evaluated by both computer simulations and experimental tests. The results obtained in both parts are presented and discussed. For suppression of rigid body vibration, the performance of the commonly used translational absorber was compared to those of a rotational absorber and the proposed absorber. From the numerical analysis, it was found that the translational one has the poorest performance in terms of the range of the absorption frequency; rotational absorber is better while the proposed absorber can completely absorb all the rigid body vibrations. For flexural vibration of continuous structures such as beams and plates, the performance of the commonly used translational absorber was compared to those of the rotational absorber and the proposed absorber by finite element analysis and experimental tests. It was found that the proposed type of absorber provides excellent performance and simpler implementation than those of the standard sprung mass absorbers as reported in textbooks and other published literature. Even though there are many techniques for the optimization of tuning and location of vibration absorbers as reported in the literature, most of them require highly computational intensive analysis before the user can determine the tuning values and the best location of the absorber. The proposed absorber is a combination of translational and rotational absorbers to be attached onto the vibrating structure at a single point. With the knowledge of the modal parameters of the structures, it is straightforward to determine an effective attachment point for suppression of vibration. The numerical predictions are verified by experimental tests.