탄소강화플라스틱 소재의 복합 가진에 따른 동특성 분석

The modal parameter of a carbon-fiber-reinforced plastic(CFRP) can be obtained through frequency response functions. It has been reported to vary with operational conditions, temperature, spectral loading patterns, as well as the direction of the carbon fibers. Previous studies have shown the sensitivity of modal parameters to three parameters. For example, five specimens were used to conduct a uniaxial excitation test by changing the direction of the carbon fibers. The effect of the spectral loading pattern was only evident for the modal damping coefficient of CFRP specimens and two different spectrum patterns, random and harmonic, were applied for uniaxial excitation. In this study, the mixed mode was considered to evaluate the sensitivity of modal parameters of CFRP specimens; the uniaxial excitation condition used was the same as that in previous studies. The mixed mode of excitation is also known as the sine-on-random(SOR) mode and is frequently applied in the military as an advanced vibration test code. The modal parameters from the mixed mode were compared to the results of the conventional single mode, random and harmonic, and the dynamic behavior of CFRP specimens was evaluated under the mixed excitation condition.