增强纤维约束混凝土柱应力-应变模型RBFNN改进计算方法

AN IMPROVED CALCULATION METHOD FOR STRESS-STRAIN MODEL OF FRP-CONFINED CONCRETE BY USING RBF NEURAL NETWORK

  • 摘要: 为提高增强纤维约束混凝土柱应力-应变模型中特征点(峰值应力、应变)的计算精度,针对已有文献资料提出的特征点近似计算公式的不足,引入径向基函数,以混凝土轴心抗压强度、FRP抗拉强度、FRP环向约束体积比、拐角半径与截面短边比值及截面长宽比为输入参数,峰值应力比、峰值应变比为输出参数,建立特征点的径向基网络模型。模型计算结果表明,采用训练成熟的径向基网络模型具有较高的非线性映射能力,可较大幅度提高特征点的计算精度与效率。在此基础上,利用模型计算结果改进已有应力-应变模型,并编制了相应的计算程序,结果表明,改进算法的计算结果与其他文献报道的试验结果吻合良好,具有较广泛的适用性。

     

    Abstract: A new method based on Radial Basis Function Neural Network (RBFNN) is proposed to improve the accuracy of existing calculation method for key points (ultimate stress and strain) in stress-strain model for FRP-confined concrete. In RBFNN model, concrete axial strength, tensile strength of FRP, FRP volumetric ratio, corner radius-to-section width ratio and aspect ratio were considered as input factors, and the compressive strength ratio and ultimate strain ratio were adopted as output factors. Trained by existing experimental data, RBFNN with highly non-linear reflection relationship was founded and proved to be more effective and accurate in calculating the key points in stress-strain model. Combining RBFNN method with the existing stress-strain model, an improved calculation method is put forward to predict stress-strain curves, the calculated results show reasonable agreement with other test results.

     

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