The Control of Local Vibration Modes of a Box Structure using Honeycomb Panel

A previous paper presented at this conference showed that there were structure-borne noise problems in Hong Kong due to shuttling trains passing on concrete viaducts and through tunnels. The dominant frequency range of such noise and vibration radiating from these concrete viaducts is between 20 Hz and 157 Hz with tonal peaks at 43 Hz and 54 Hz (bandwidth resolution is 1 Hz). The previous paper showed that the sound radiation is attributed mainly to the bending vibration mode of the concrete viaduct’s cross-section. Thus it is necessary to investigate the detail bending vibration mode shape. Though the vibration analysis of truss or plate structures has been thoroughly studied but there were very few studies focused on the cross-section of concrete viaduct. Another paper constructed a scaled reinforced concrete frame model to study the structural response with generalized ground shock excitations and this paper noted the significance of the structural local modes at high frequency (68 Hz, 76 Hz). The paper pointed out that these local modes were uncoupled from the global response and that the edges at the joints were fixed in displacement. The local mode shape of the scaled reinforced concrete frame model is similar to the local mode shape of cement viaduct in the present study. In other work on the periodic rib-skin structure of semi-rigid construction, it was noted that some natural modes had edge displacement coupling co-ordinates ‘free’, but rotational coupling co-ordinates ‘locked’. The result suggested that in a viaduct box, the web face, which supports the top face, is likely to be flexible in the vertical displacement. In this study a cement viaduct model is excited at the center and web positions and the corresponding vibrations are measured. The global mode (bending along the span only) and local modes (bending on cross-section elements) including center and web modes are identified and analyzed. The local vibration modes of the cement viaduct’s cross-section are independently checked by finite element methodology.

• Corporate Authors:

  Institute of Noise Control Engineering

  Iowa State University, 210 Marston Hall
  Ames, IA  United States  50011-2153

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Ngai, K W
  • Lee, Y Y
  • Ng, C F
• Conference:
  • Noise-Con 04. The 2004 National Conference on Noise Control Engineering
  • Location: Baltimore Maryland, United States
  • Date: 2004-7-12 to 2004-7-14
• Publication Date: 2004

Language

• English

Media Info

• Media Type: CD-ROM
• Features: Figures; Photos; References;
• Pagination: pp 515-523
• Monograph Title: Noise-Con 04. The 2004 National Conference on Noise Control Engineering

Subject/Index Terms

• TRT Terms: Bandwidth; Finite element method; High frequency; Honeycomb structures; Railroad tunnels; Shuttle service; Tunnels; Vibration; Vibration control
• Geographic Terms: Hong Kong (China)
• Subject Areas: Bridges and other structures; Energy; Environment; Highways; Operations and Traffic Management; Passenger Transportation; Railroads; I15: Environment;

Filing Info

• Accession Number: 01054336
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Jul 26 2007 11:26AM