ABSTRACT Most of the practical engineering structures exhibit nonlinearity due to nonlinear dynamic characteristics of structural joints, nonlinear boundary conditions, and nonlinear material properties. In this paper, we investigate the effectiveness of five selected frequency domain techniques for the detection of nonlinear behaviour of the structure. Numerical simulation studies have been carried out by choosing a typical benchmark problem i.e., spring-mass system. The strength and weaknesses of each of the technique are evaluated with respect to their sensitivity to measurement noise. Efforts are also made in this paper to estimate the degree of nonlinearity present in the system using all the five techniques. Numerical investigations are later complemented with experimental studies to demonstrate their practical applicability. The investigations carried out in this paper clearly highlight the effectiveness of the bispectrum technique in robustly identifying the presence and also the degree of nonlinearity in the system.

中文翻译：

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使用频域方法检测和量化非线性结构行为

摘要 由于结构节点的非线性动力特性、非线性边界条件和非线性材料特性，大多数实际工程结构都表现出非线性。在本文中，我们研究了五种选定的频域技术在检测结构非线性行为方面的有效性。通过选择一个典型的基准问题，即弹簧质量系统，进行了数值模拟研究。每种技术的优势和劣势都根据它们对测量噪声的敏感性进行评估。本文还努力使用所有五种技术来估计系统中存在的非线性程度。数值研究后来与实验研究相辅相成，以证明其实际适用性。