一种时域载荷识别数值算法及其不适定性研究

发布时间：2018-04-04 21:10

本文选题：杜哈梅积分　切入点：载荷识别　出处：《应用力学学报》2017年02期

【摘要】：某结构在试验中,经历了持续时间很短的出水过程,试验中获得了该状态下关键位置响应的时间历程,需进行结构试验环境适应性分析。本文将杜哈梅卷积积分离散化,推导了时域内载荷与响应之间的传递函数矩阵;基于该传递矩阵的逆运算发展了一种时域内载荷识别方法,该方法在数值仿真过程中往往出现累计误差过大导致不收敛的现象,研究分析发现这属于反问题中典型的不适定性问题,并采用最速下降法有效克服了该不适定性问题;同时还考察了该算法在不同信噪比下的识别精度。研究结果表明,正弦、随机、半正弦冲击等多种载荷均获得了较准确的识别结果。本文提出的方法便于复杂工程结构有限元模型的应用。
[Abstract]:In the test, a certain structure experienced a short duration of effluent process, and the time course of the key position response was obtained in the test, so the adaptability analysis of the structure test environment was needed.In this paper, the Duhamet convolution integral is discretized, the transfer function matrix between load and response in time domain is derived, and a method of load identification in time domain is developed based on the inverse operation of the transfer matrix.In the process of numerical simulation, this method often has the phenomenon that the accumulated error is too large and leads to no convergence. The research and analysis show that this is a typical ill-posed problem in the inverse problem, and the steepest descent method is used to overcome the ill-posed problem effectively.At the same time, the recognition accuracy of the algorithm in different signal-to-noise ratio (SNR) is also investigated.The results show that the identification results of sinusoidal, random and semi-sinusoidal loads are more accurate.The method presented in this paper is convenient for the application of finite element model of complex engineering structures.
【作者单位】：中国工程物理研究院总体工程研究所;
【基金】：国家自然科学基金(11302207;11472256) 中国工程物理研究院院长基金(YZ2015011)
【分类号】：TB115

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