基于神经网络的输电塔钢管构件涡激振动幅值预测方法

PREDICTION METHOD FOR VORTEX-INDUCED VIBRATION AMPLITUDE OF STEEL TUBES IN TRANSMISSION TOWERS BASED ON NEURAL NETWORK

  • 摘要: 输电塔中长细比较大的钢管构件容易发生低风速下的涡激振动,鉴于传统风洞试验和数值模拟研究方法存在的成本高、周期长的局限,该文提出了一种基于神经网络的输电塔钢管构件涡激振动幅值高效预测方法。为获取训练模型所需的数据集,发展了适用于任意插板形式、几何尺寸的钢管构件涡激振动响应分析方法;结合多种神经网络模型(BPNN、PSO-BPNN、RBFNN、GRNN)以及性能评价指标,建立了基于神经网络的输电塔钢管构件涡激振动幅值预测方法;通过算例对某C型插板和十字型插板钢管构件涡激振动幅值进行了预测。研究表明:通过与试验结果的对比,验证了该文输电塔钢管构件涡激振动响应分析方法的准确性,对于C型和十字型插板钢管构件VIV幅值的相对误差分别为3.84%和5.87%,利用该方法可为神经网络模型提供可靠样本;通过7折10次交叉验证优化超参数后的4种神经网络模型,均表现出较好的预测精度;相比之下,GRNN在C型插板和十字型插板钢管构件算例中均呈现出最佳的泛化能力,其R2值分别为0.989和0.992;采用GRNN方法可以较好地预测C型和十字型插板钢管构件在不同质量阻尼比参数下的VIV幅值,且在计算效率上相比于CFD方法具有明显的优势。

     

    Abstract: In transmission towers, steel tubes with large slenderness ratio are prone to vortex-induced vibration (VIV) under low wind speed. In view of the high cost and time-consuming of traditional wind tunnel test and numerical simulation methods, an efficient VIV prediction method for steel tubes of transmission towers based on neural network is proposed in this paper. In order to obtain the data set, a VIV response analysis method is developed for steel tubes with arbitrary connection joints and geometric sizes. By employing a variety of neural network models (BPNN, PSO-BPNN, RBFNN, GRNN) and performance evaluation method, a prediction method of VIV for steel tubes of transmission towers is established. C-shaped and cross-shaped bolts joints steel tubes are selected as examples, and the VIV amplitudes are predicted. The results show that: Through a comparison with experimental results, the accuracy of the proposed method of VIV for steel tubes is verified, and the relative error of maximum VIV amplitude is 3.84% and 5.87%, respectively for C-shaped and cross-shaped steel tubes, so the proposed method can provide reliable samples for neural network models. After the optimization of hyper parameters through 7-fold for 10 times cross validation, all the 4 types of neural network models show excellent prediction accuracy; the GRNN shows the best generalization ability for both C-shaped and cross-shaped steel tubes with R2 values of 0.989 and 0.992, respectively. The GRNN model can well predict the maximum VIV amplitude of C-shaped and cross-shaped steel tubes with different reduced mass damping parameters, and has obvious advantages over CFD methods in terms of computational efficiency.

     

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