An efficient dynamic load identification method for nonlinear structures is proposed. Assuming that the nonlinear elements of a structure can be separated, or the structural kinetic equation can be available, the whole structural damping and stiffness matrices can be divided into linear and nonlinear sub matrices. Regarding the effects of the nonlinear elements on the linear ones as dynamic load constraints, which can be realized by moving the product of the nonlinear sub matrices and their corresponding responses to the right-hand side of the original kinetic equation, a remaining linear structure subjected to multi-source of dynamic loads can then be obtained. The instability of the obtained structure caused by the load equivalence is discussed and improved. The case that the characteristics of the nonlinear parameters are unknown is also investigated. Finally, based on the improved structure, Green’s kernel function method, LSQR regularization is employed to reconstruct the dynamic loads. The effectiveness of the proposed method is proved by two numerical examples and an engineering application.

中文翻译：

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作用在非线性结构上的动态载荷的等效识别方法

提出了一种有效的非线性结构动载荷识别方法。假设结构的非线性元素可以分离，或者结构动力学方程可以得到，整个结构阻尼和刚度矩阵可以分为线性和非线性子矩阵。将非线性元素对线性元素的影响作为动态载荷约束，可以通过将非线性子矩阵的乘积及其对应的响应移动到原始动力学方程的右侧，剩下的线性结构受到然后可以获得多源动态载荷。讨论并改进了由等效荷载引起的所得结构的不稳定性。还研究了非线性参数特性未知的情况。最后，在改进结构的基础上，采用格林核函数法，LSQR正则化重构动态载荷。通过两个数值算例和一个工程应用证明了所提方法的有效性。