Vehicle-Pier Impact Force Research Based On Neural Network

Bridges play an extremely important role as a link between intra-city and inter-city transportation networks.With the acceleration of China’s urbanization process and the construction of national highways and railway networks,more and more bridges have emerged.At the same time,the risk of accidents,especially driving accidents,of cross-line bridges is constantly increasing,due to subjective reasons such as improper operation of drivers,drunk driving,and objective reasons such as vehicle punctures and sudden traffic accidents Accidents that cause vehicles to hit a pier or a bridge superstructure occur from time to time.In this paper,the common column-type reinforced concrete bridge pier is selected as the research object,and the finite element analysis of the collision process is performed.At the same time,a neural network was introduced to study the vehicle-pier impact force.The main research contents are as follows:(1)ANSYS / LS-DYNA finite element software was used to carry out numerical simulation analysis on the test conditions of the trolley impacting the reinforced concrete column in the reference.By analyzing the energy time history curve of the finite element calculation result and comparing the impact of the finite element analysis result with the test result Force time history curve and displacement time history curve verify the correctness of the modeling.(2)Prototype bridge piers are established using validated finite element model modeling parameters.The vehicle model is selected from the medium-duty truck model and light-duty truck model issued by the National Collision Center(NCAC).The effects of different influencing factors(vehicle load,vehicle speed,impact area between the vehicle and the pier,impact eccentricity,pier concrete strength,pier hoop spacing)on the vehicle-pier impact force were studied.The research results show that the vehicle load,vehicle speed and impact eccentricity have a greater impact on the vehicle-pier impact force,while the vehicle-pier impact area has a smaller effect on the vehicle-pier impact force,and the pier concrete strength and bridge pier hoop spacing affect the vehicle.-The impact of the pier impact is small.(3)Introduce two artificial neural networks,BP neural network and RBF neural network,and use MATLAB scientific computing software to program the two neural networks.Analyze the impact factors of vehicle-pier impact force,select vehicle load,vehicle speed,and eccentricity as the input vector of the neural network,and use the impact force as the output vector to establish 120 groups of neural network models.110 sets of data were randomly selected to train the neural network,and the remaining 10 sets of data were used for verification.The prediction results show that both neural networks can predict the impact force,and the BP neural network has a better prediction effect.The trained BP neural network is used to predict the existing research results,and the results show that the prediction error of the BP neural network is within 20%.