Determining optimal eccentric mass parameters for mitigating torsional vibrations in floating structures

Abstract

Floating structures are not limited to floating docks in hydraulic engineering; rather, they have found increasing applications across various fields such as civil engineering, offshore wind turbines... Herein, floating houses have become particularly prevalent in Vietnam such as in Chau Doc, An Giang. Due to the complex nature of environmental loads-comprising waves, wind, and current-acting on floating structures, investigating methods to mitigate structural vibrations is of considerable importance. This article proposes a simplified rule for determining the optimal parameters of eccentric mass dampers to suppress torsional vibrations in floating structures under harmonic excitation. The optimisation is performed using Den Hartog’s classical method, and the results are benchmarked against those obtained via numerical simulations. To illustrate the proposed approach, a detailed numerical example is presented. The illustrative example demonstrates that the obtained parameters are reasonable when compared with the optimisation results using the genetic algorithm. Furthermore, the computational formula proposed by J.P.D. Hartog has been extended to apply not only to single-degree-of-freedom translational systems but also to torsional vibration systems.