Real-time evaluation and prediction of spatial temperature field and temperature effect of steel-concrete composite bridge deck system based on BP-LSTM hybrid model
Liu Yang1,2 Xiang Shengtao1 Wang Da1，3
1. Changsha University of Science & Technology, Changsha 410114, China; 2. Hunan University of Technology, Zhuzhou 412007, China;
3. Central South University of Forestry & Technology, Changsha 410004, China
Abstract：Considering the deficiency of traditional health monitoring system and finite element method, a real-time evaluation and prediction method based on multi-layer feedforward—long and short term memory (BP-LSTM) hybrid model was proposed to realize the real-time evaluation and prediction of steel-concrete composite bridge deck system temperature and temperature effect. The health monitoring system data of a bridge was were analyzed, the thermo-mechanical finite element method analysis was used to expand the data, and a sample database containing the mapping of “structural characteristics, time characteristics, environmental characteristics—temperature and temperature effect” was constructed. The accuracy of the finite element calculation was verified by the measured data. The structure of BP-LSTM hybrid model was designed, and the LSTM network was improved by considering the MSE loss function of the time weight. The hybrid model with high output accuracy was obtained by reading the data into the sample database for training, verification and testing. Finally, a method for real-time evaluation and prediction of temperature and temperature effect by using BP-LSTM hybrid model was proposed. The results show that the finite element calculation results of structural temperature field based on the meteorological data agree well with the measured results. The mapping of “structural characteristics, time characteristics, environmental characteristics—temperature, temperature effect” is highly nonlinear. The single BP network or LSTM network has poor effect, while the mixed model of BP-LSTM has high precision. By the the proposed real-time evaluation and prediction method, the determination coefficients between the output value and the target value of the mixed model are determined as 0.930 at the lowest and 0.993 at the highest. The research results can provide reference for real-time evaluation and prediction of spatial temperature field and temperature effect of steel-concrete composite bridge deck system.
刘扬 向胜涛 王达. 基于BP-LSTM混合模型的钢-混组合桥面系空间温度场及温度效应实时评估及预测[J]. 土木工程学报, 2021, 54(11): 57-70, 78.
Liu Yang Xiang Shengtao Wang Da. Real-time evaluation and prediction of spatial temperature field and temperature effect of steel-concrete composite bridge deck system based on BP-LSTM hybrid model. 土木工程学报, 2021, 54(11): 57-70, 78.
