基于参数识别和神经网络代理模型的实时混合试验方法

REAL-TIME HYBRID SIMULATION METHOD BASED ON PARAMETER IDENTIFICATION AND NEURAL NETWORK SURROGATE MODEL

  • 摘要: 目前,实时混合试验的应用受到数值子结构计算效率低的限制,无法拓展到大型复杂结构模型的抗震试验。为此,提出了一种基于参数识别和神经网络代理模型的实时混合试验方法。该方法首先以试验子结构的本构参数作为输入,采用神经网络建立数值子结构的代理模型;然后在试验中在线识别试验子结构的本构参数,利用代理模型预测数值子结构边界上的位移。该方法的核心在于,神经网络的输入是试验子结构的本构参数而非恢复力,这样即使预测出的位移有误差,也不会影响本构参数的识别,因此预测误差不会向后传递,从而保障了数值子结构代理模型的精度。以带防屈曲支撑的8层钢筋混凝土框架结构作为研究对象,取底层一个阻尼器作为试验子结构,利用所提方法开展了实时混合试验仿真,结果表明,所提代理模型具有良好的精度,并大幅提高了计算效率。

     

    Abstract: Currently the application of real-time hybrid simulation is limited by the low computational efficiency of numerical substructures, thus cannot be extended to the seismic tests of large and complex structural models. In this case, a real-time hybrid simulation method based on parameter identification and neural network surrogate model is proposed. The method first adopts a neural network to establish a surrogate model for the numerical substructure, with the constitutive parameters of the experimental substructure as the inputs of the neural network; then these constitutive parameters are identified online during the test, and the surrogate model is used to predict the boundary displacement of the numerical substructure. The core of this method is that the inputs of the neural network are the constitutive parameters of the experimental substructure instead of the restoring forces, so that even if there is an error in the predicted displacement, it will not affect the identification of the constitutive parameters, thus the prediction error will not be passed to the next time step. This ensures the accuracy of the surrogate model for the numerical substructure. Virtual real-time hybrid simulation on an 8-story reinforced concrete frame structure with buckling-restrained braces was conducted using the proposed method, in which a damper at the bottom story was taken as the experimental substructure. The results show that the proposed surrogate model has good accuracy and computational efficiency.

     

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