说明：  利用分布参数系统的传递函数法对带有扩展层的约束阻尼梁进行编程分析，得到频率响应曲线，并获得位移峰值对应的频率，即固有频率。
(The transfer function method of distributed parameter system is used to analyze the constrained damping beam with extended layer, and the frequency response curve is obtained, and the frequency corresponding to the peak displacement is obtained, that is the natural frequency.)