Vibration and Rattle Mitigation

High levels of low frequency noise are created by aircraft during take-off and landing. A by-product of low frequency sound incident on a building façade is the excitation of structures within the building into vibrations. Such acoustically-induced structural vibrations may be imperceptible, but they may cause rattle. Rattle is caused by the intermittent loss of contact between two bodies due to vibration. Rattle causes secondary noise emissions, which are often perceived as annoying. Investigation of the mechanisms leading to rattle onset and the development of rattle mitigation strategies are needed to reduce rattle emissions, and the associated annoyance. Analytical models of idealized systems which have the potential to rattle were developed in this investigation. Comparisons were made between model predictions and results from experiments. From the analytical models, rattle onset thresholds were determined for simple models of various household components such as: window systems, wall hangings, door latches and bric-a-brac. The analytical rattle onset models provide guidelines for design to mitigate rattle. The analytical models are lumped-parameter, single-degree-of-freedom models of elements typically found in homes. The models are divided into two classes: resonant and non-resonant systems. Previous research conducted by others have used non-resonant models to describe rattle. These models describe some practical systems. However, many systems rattle because of resonant properties. It is assumed that the response of multi-degree-of-freedom systems may be modeled as a superposition of single-degree-of-freedom systems. This investigation will focus only on single-degree-of-freedom systems. Rattle criteria are developed for various excitation sources including harmonic base motion and forced excitation. These criteria include the rattle onset threshold and the rattle bandwidth, which is a feature of resonant systems. An in-situ experiment was conducted at the Ray W. Herrick Laboratories. Four windows known to be susceptible to rattle were excited via high-fidelity playback of three high-amplitude, low-frequency noise signals. The signals included pre-recorded aircraft take-off noise, a swept sine signal, and random noise. The vibration and acoustic response of each of the windows was measured to determine the relationship between frequency and acceleration level for onset of rattle and qualitatively validate the behavior predicted by the analytical models.


  • English

Media Info

  • Media Type: Digital/other
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 122p

Subject/Index Terms

Filing Info

  • Accession Number: 01873172
  • Record Type: Publication
  • Report/Paper Numbers: PARTNER-COE-2008-004, PARTNER Project 1.6 Report
  • Contract Numbers: FAA 03-C-NE-PU-029
  • Created Date: Feb 14 2023 5:48PM