点簧簧片振动特性数值分析*

簧片是笙等中国传统簧管类乐器的核心部件之一。通过点簧工艺可调整簧片振动频率,点簧簧片的差异对整体乐器的声音效果具有重要影响。针对点簧簧片的振动特性问题,对其建立非均匀截面并具有质量负载的振动模型,采用有限元方法计算点簧簧片的固有频率。大量算例分析了点簧质量、位置以及簧片的边界条件对振动频率的影响,研究发现:若点簧质量不变,位置越靠近自由端调整频率越大,但同时应考虑对高阶频率的激发避免影响音色;若位置相同,点簧质量与频率改变近似成正比,由此可方便调整簧片振动频率。该文研究结果初步揭示了点簧簧片振动规律,可为制作、复原传统簧管类乐器中簧片的点簧工艺过程提供物理依据。

Numerical analysis of the vibration of metallic reed with mass

The reed is one of the core parts of Chinese traditional reed instruments such as Sheng. The vibration frequency of the reed can be adjusted by the metallic reed with mass technology, so the difference of the metallic reed with mass has an important influence on the sound effect of the whole instrument. Aiming at the vibration characteristics of metallic reed with mass, a vibration model with non-uniform cross section and mass load was established, and the natural frequency of metallic reed with mass was calculated by finite element method. A large number of examples were used to analyze the influence of the mass, position and boundary conditions of the reed on the vibration frequency. The results show that if the mass remains unchanged, the closer the position is to the free end, the higher the adjustment frequency will be. However, at the same time, the excitation of the high frequency should be considered to avoid affecting the timbre. If the position is the same, the mass is proportional to the change of frequency, thus the vibration frequency of reed can be adjusted conveniently. The results of this study preliminarily reveal the vibration rule of metallic reed with mass, which can provide a physical basis for making and restoring the metallic reed with mass process of reed in traditional reed instruments.