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Frequency effects in graphite/epoxy composites are examined in performing fatigue tests at different frequencies and different stress levels. The life data is correlated well by a damage model proposed with only strain as the governing variable. Further, the use of dynamic modulus and creep strain as measures of damage is investigated.

The gong, a Chinese traditional musical instrument, is generally made of copper in a circular shape. The finite element model of the gong is first constructed to perform theoretical modal analysis (TMA). So, the natural frequencies and corresponding mode shapes can be obtained. Experimental modal analysis (EMA) is also carried out. Results show that both natural frequencies and mode shapes match quite well between TMA and EMA. The radiated sound spectra of the gong are also measured and compared with the vibration modes to identify its principal frequency of radiated sound. Through the validated finite element model, the effect of geometric dimensions and material properties of the gong on its vibration modes and sound characteristics is also studied.

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