Experimental study of mode shifting in an asymmetrically heated rectangular plate
| Autor: | Elias Lopez-Alba, Eann A. Patterson, Ana Catarina Santos Silva, C. M. Sebastian |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Digital image correlation
Materials science Acoustics and Ultrasonics business.industry Mechanical Engineering Mode (statistics) 02 engineering and technology Waterfall plot Condensed Matter Physics 01 natural sciences 020303 mechanical engineering & transports Planar Optics 0203 mechanical engineering Buckling Mechanics of Materials Normal mode 0103 physical sciences Shaker business 010301 acoustics Laser Doppler vibrometer |
| Zdroj: | JOURNAL OF SOUND AND VIBRATION |
| Popis: | Modal shifting and jumping in thermally buckled plates has been investigated previously using computational models; however, relatively few experimental explorations have been reported. In this study, the modal shifts and jumps in a simple rectangular plate or panel were investigated using digital image correlation to obtain detailed mode shapes. One face of the planar panel, which was 219 × 146 mm, was speckled and viewed with a stereoscopic digital image correlation system using pulsed-laser illumination and with a laser vibrometer at a single point. The other face was heated using a set of 1 kW quartz lamps to produce a non-uniform temperature distribution which progressively increased from room temperature to around 760 K. An infra-red camera recorded the time-varying temperature distribution on the panel while it was excited with an electrodynamic shaker. A waterfall plot, or time-frequency spectrogram, showing natural frequencies as a function of time was generated, which highlighted the shifting response of the panel with temperature. The heating sequence was repeated and the panel excited at the natural frequencies identified in the waterfall plot, which permitted the corresponding mode shapes to be measured. These data showed that mode shifting and jumping was present with asymmetric heating, but not with spatially uniform heating, and was associated with thermally-induced buckling. |
| Databáze: | OpenAIRE |
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