基于描述函数法的典型结构非线性识别方法研究

目的为典型的结构非线性提供识别方法。方法基于动力学基本理论,对典型结构非线性系统在建模时,将非线性单元产生的非线性力作为位移或速度的函数加入到潜在的线性系统中,对不同激励量级的频响函数加以分析,通过描述函数法识别非线性单元的位置、类型和参数。结果通过Matlab编程进行仿真验证,使用描述函数法对非线性系统进行识别,成功对三种不同情况的非线性系统实现了非线性单元识别。结论描述函数法识别的非线性位置是准确的,类型是匹配的,参数准确度极高。

Nonlinear Identification Method of Typical Structure Based on Describing Function Method

Objective To provide methods for identification of typical structural nonlinear. Methods Based on the basic theory of dynamics, when the typical structural nonlinear system was modeled, the nonlinear force generated by the nonlinear elements was added to the underlying linear system as a function of displacement or velocity. By analyzing frequency response function of different excitation levels, location, type and parameters of nonlinear elements were determined through the describing function method. Results The method was verified by Matlab simulation. The nonlinear elements of three different nonlinear systems were identified successfully with the describing function method. Conclusion When the describing function method is used to identify nonlinear element, the location is accurate, the type is matched, and the parameter accuracy is very high