An inverse method for distributed dynamic load identification of structures with interval uncertainties

2019 ◽  
Vol 131 ◽  
pp. 77-89 ◽  
Author(s):  
Lei Wang ◽  
Yaru Liu ◽  
Yisi Liu
2018 ◽  
Vol 38 (3) ◽  
pp. 0328012
Author(s):  
宋雪刚 Song Xuegang ◽  
刘鹏 Liu Peng ◽  
程竹明 Cheng Zhuming ◽  
魏真 Wei Zhen ◽  
喻俊松 Yu Junsong ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Chunsheng Liu ◽  
Chunping Ren

A new signal processing algorithm was proposed to identify the dynamic load acting on the coal-rock structure. First, the identification model for dynamic load is established through the relationship between the uncertain load vector, and the assembly matrix of the responses was measured by the machinery dynamic system. Then, the entropy item of maximum entropy regularization (MER) is redesigned using the robust estimation method, and the elongated penalty function according to the ill-posedness characteristics of load identification, which was named as a novel improved maximum entropy regularization (IMER) technique, was proposed to process the dynamic load signals. Finally, the load identification problem is transformed into an unconstrained optimization problem and an improved Newton iteration algorithm was proposed to solve the objective function. The result of IMER technique is compared with MER technique, and it is found that IMER technique is available for analyzing the dynamic load signals due to higher signal-noise ratio, lower restoration time, and fewer iterative steps. Experiments were performed to investigate the effect on the performance of dynamic load signals identification by different regularization parameters and calculation parameters, pi, respectively. Experimental results show that the identified dynamic load signals are closed to the actual load signals using IMER technique combined with the proposed PSO-L regularization parameter selection method. Selecting optimal calculated parameters pi is helpful to overcome the ill-condition of dynamic load signals identification and to obtain the stable and approximate solutions of inverse problems in practical engineering. Meanwhile, the proposed IMER technique can also play a guiding role for the coal-rock interface identification.


2020 ◽  
Vol 103 (3) ◽  
pp. 003685042093128 ◽  
Author(s):  
Linjun Wang ◽  
Yang Huang ◽  
Youxiang Xie ◽  
Yixian Du

Dynamic forces are very important boundary conditions in practical engineering applications, such as structural strength analysis, health monitoring and fault diagnosis, and vibration isolation. Moreover, there are many applications in which we have found it very difficult to directly obtain the expected dynamic load which acts on a structure. Some traditional indirect inverse analysis techniques are developed for load identification by measured responses. These inverse problems about load identification mentioned above are complex and inherently ill-posed, while regularization methods can deal with this kind of problem. However, most of regularization methods are only limited to solve the pure mathematical numerical examples without application to practical engineering problems, and they should be improved to exclude jamming of noises in engineering. In order to solve these problems, a new regularization method is presented in this article to investigate the minimum of this minimization problem, and applied to reconstructing multi-source dynamic loads on the frame structure of hydrogenerator by its steady-state responses. Numerical simulations of the inverse analysis show that the proposed method is more effective and accurate than the famous Tikhonov regularization method. The proposed regularization method in this article is powerful in solving the dyanmic load identification problems.


2013 ◽  
Vol 22 (7) ◽  
pp. 1062-1076 ◽  
Author(s):  
Xingsheng Sun ◽  
Jie Liu ◽  
Xu Han ◽  
Chao Jiang ◽  
Rui Chen

Author(s):  
Jinhui Jiang ◽  
Huangfei Kong ◽  
Hongji Yang ◽  
Jianding Chen

Load identification has long been a difficult issue for distributed load acting on structures. In this paper, the dynamic load identification technology based on the modal coordinate transformation theory is developed for dealing with identification problem of the two-dimensional thin plate structure. For the distributed dynamic load acting on a plate, we decompose it with the mode functions in the modal coordinate space and establish the liner relationship between the time function coefficients of the distributed load and the modal excitations which are solved out based on the known response data of the measuring points. Then the distributed dynamic load is rebuilt based on orthogonal decomposition and inverse Fourier Transform method. The simulation examples and elastic thin plate structure tests show that the proposed method has a good accuracy with the allowable error range and is reliable and practical. The proposed method can be also used for load identification of complicated structures in a wide range of engineering applications.


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