Experimental determination of the damping ratio of a thermal insulation cover plate

✍ Scribed by Henri Fenech

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 512 KB
• Volume: 19
• Category: Article
• ISSN: 0003-682X
• DOI: 10.1016/0003-682x(86)90015-0

✦ Synopsis

Systems circulating fluids within closed boundaries generate noise produced by the circulator, turbulence in the flow, vortex shedding, etc. The ducting containing the flowing fluid acts as a generator oj additional noise and as a filter amplijying the noise at discrete jrequencies (i.e. normal mode of vibrations oJ the structural boundary).

The damping ratio oJthese structures is an important parameter which controls the amplitude oj the vibrating structure and the noise level at discretej?equencies transmitted by that structural boundary. An equally important consideration is the amplitude oJthe structure vibration which can cause early jailure oJ the boundary (resonance response) or longerterm Jatigue jailure. The damping ratio depends on the geometrical configuration and numerous boundary conditions. It cannot be predicted accurately by analysis and must be determined experimentally. This paper describes an experiment on the measurement oJthe damping ratio oJ a commonly used structure (i.e. a square plate cover with kaowool fiber insulation backup). The ~neasured values oJ the damping ratio are given Jor two diJJerent sizes of plate with diJJerent attachments. The effects oJ the configuration and attachments on the damping ratio are discussed.