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Reducing structure‐borne noise in thin‐walled structures by local thickness variations
Author(s) -
Miksch Matthias,
Aumann Quirin,
Müller Gerhard
Publication year - 2018
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.201800177
Subject(s) - dissipation , bending , materials science , vibration , noise (video) , energy (signal processing) , acoustics , amplitude , structural engineering , computer science , optics , composite material , physics , engineering , image (mathematics) , quantum mechanics , thermodynamics , artificial intelligence
Thickness variations can modulate the propagation of bending waves in thin‐walled structures. A smooth reduction of the thickness results in a decreasing propagation speed and an increasing amplitude of the bending wave. Acoustic black holes (ABH) make use of this modulation to enhance the energy dissipation in the vicinity of this thickness diminution. Using the concept of ABH, no additional mass is needed to reduce structure‐borne noise. Therefore, this concept is suitable for reducing the vibrational energy in lightweight structures, which is vital in aerospace and automotive applications, among others. Locally modifying the thickness of a structure can significantly influence the global energy distribution in the structure. This contribution investigates the influence of different local thickness profiles on the global energy distribution. The results deliver insights for the design of such thickness variations in thin‐walled structures to improve their vibrational behavior. Several numerical models are evaluated to assess the dependency between the geometric design parameters of the thickness variation and the energy distribution in the structure.