大钟拍声的调整实验

阐明大钟拍声的发生原理，并用大钟振动拍的理论模型说明拍的特性，从而控制清晰度。在实验钟上附着质量，根据附着质量位置的不同，能够改变其非对称程度，进一步调整拍频，同时用有限元分析的结果和等效圆环理论计算的结果对比。引入等效圆环理论，通过建立一个理论上带有附加质量的轴对称圆环模型，达到具有和大钟相同的振动特性。根据模型，得到在大钟特定位置附加的质量，以同时调整所需拍的清晰度和周期。在大钟多个位置进行实验，并进行有限元分析，验证了该理论的有效性。

Adjust to the beat of bell

Illustrated the occurrence principle of the beat of bell, and explain the characteristics of beat with the theoretical model of bell vibration beat, so as to control the clarity of beat. According to the positon and quantity of added mass to the surface of bell, which could change the asymmetry degree of bell, then the beat frequency could be changed, while comparing text results with results of finite element analysis and results of equivalent ring theory. The equivalent ring theory is introduced to achieve the same vibrational characteristics as the test bell by establishing a theoretical axisymmetric ring model with added mass. According to the model, the added mass at a specific position of the test bell can be calculated to adjust the clarity and period of desired beat simultaneously. The validity of theory has been verified by testing at multiple locations of bell and finite element analysis.