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采用谱单元方法推导带阻尼梁的传递函数矩阵. 采用一维连续梁的解析解作为动力形状函 数. 与有限元法相比，谱单元方法的自由度和单元数目小且计算精度高. 传递函数表示为梁 的几何和物理参数的超越隐函数，不同于用模态参数表示的传统传递函数. 提出了采用遗传 算法的结构物理参数识别方法. 以变截面悬臂梁为数值算例，显示该方法的有效性.

IDENTIFICATION OF PHYSICAL PARAMETERS IN BEAM STRUCTURES BASED ON SPECTRAL ELEMENT METHOD

The transfer function matrix of a beam with damping is derived by means of spectral element method (SEM). The analytical solution for a one-dimensional beam is applied in the form of shape functions in continuous form. Compared to the finite element method, the spectral element method can be used to obtain high precision with less degrees of freedom and elements. The proposed transfer function is represented by the transcendental function with geometrical and physical parameters of the beam, and is different from the traditional transfer function, represented by modal parameters. A new method to identify physical parameters of a beam structures based on the genetic algorithm is proposed. Two numerical examples of cantilever beams with varying cross section are given to show the effectiveness of the proposed method.