中文摘要：

采用快速傅立叶变换频谱分析仪测定了阮、月琴共鸣面板在0～1000Hz频率范围内的各阶振动频率、声振动传播速度及声辐射强度，并分析了各阶振动频率对应的振动模态。对于阮，较易测得50、135、236．25、307．5、345、435、642．5、737．5Hz等阶共振频率；对于月琴，较易测得56．25、111．25、170、322．5、371．25、438．75、570、707．5、880Hz等阶共振频率。除了共振频率在170Hz左右对应的振型，阮与月琴各阶振型基本相同，但对应的共振频率却存在差异。共鸣面板的顺纹理声振动传播速度最大，其值为横纹理方向的2倍以上。各阶共振频率频谱强度随频率增大，呈抛物线的变化规律，在300—1200Hz频率宽度内，其振动频谱强度最大。

英文摘要：

The resonant frequencies in 0-1 000 Hz of Ruan and Yukin＇ s top resonant boards were measured by FFT analyzer, and the vibration modes were also analyzed. The resonant frequencies could be easily identified in 50, 135,236.25,307.5, 345,435, 642.5 and 737.5 Hz for Ruan, and 56.25, 111.25, 170,322.5,371.25,438.75,570,707.5 and 880 Hz for Yukin. Except for 170 Hz, the vibration modes of Ruan and Yukin were similar in other orders, but the corresponding resonant frequencies were different. The sound velocity in longitudinal direction was the largest, which was more than one time faster than that in radius direction. The trend of spectrum intensity of resonance frequency could be expressed with a parabola, and the largest intensity was obtained in 300-1 200 Hz.