scholarly journals Finite Element Model Modification of Arch Bridge Based on Radial Basis Function Neural Network

2019 ◽  
Vol 136 ◽  
pp. 04033
Author(s):  
Tongqing Chen ◽  
Lei Wang ◽  
Xijuan Jiang ◽  
Yubin Wang ◽  
Kai Yan

Compared with other neural networks, Radial Basis Function (RBF) neural network has the advantages of simple structure and fast convergence. As long as there are enough hidden layer nodes in the hidden layer, it can approximate any non-linear function. In this paper, the finite element model of a through tied arch bridge is modified based on Neural Network. The approximation function of RBF neural network is utilized to fit the implicit function relationship between the response of the bridge and its design parameters. Then the finite element model of the bridge structure is modified. The results show that RBF neural network is efficient to modify the model of a through tied arch bridge.

2011 ◽  
Vol 103 ◽  
pp. 488-492
Author(s):  
Guang Bin Wang ◽  
Xian Qiong Zhao ◽  
Yi Lun Liu

In the rolling process, deviation is the phenomenon that the strap width direction's centerline deviates from rolling system setting centerline,serious deviation will cause product quality drop and rolling equipment fault. This paper has established the finite element model to the hot tandem rolling aluminum strap, analyzed the strap’s deviation rule under four kinds of incentives,obtained the neural network predictive model and the control policy of the tail deviation.The result to analyze a set of fact deviation data shows this method may control tail deviation in preconcerted permission range.


2020 ◽  
pp. 147592172093261 ◽  
Author(s):  
Zohreh Mousavi ◽  
Sina Varahram ◽  
Mir Mohammad Ettefagh ◽  
Morteza H. Sadeghi ◽  
Seyed Naser Razavi

Structural health monitoring of mechanical systems is essential to avoid their catastrophic failure. In this article, an effective deep neural network is developed for extracting the damage-sensitive features from frequency data of vibration signals to damage detection of mechanical systems in the presence of the uncertainties such as modeling errors, measurement errors, and environmental noises. For this purpose, the finite element method is used to analyze a mechanical system (finite element model). Then, vibration experiments are carried out on the laboratory-scale model. Vibration signals of real intact system are used to updating the finite element model and minimizing the disparities between the natural frequencies of the finite element model and real system. Some parts of the signals that are not related to the nature of the system are removed using the complete ensemble empirical mode decomposition technique. Frequency domain decomposition method is used to extract frequency data. The proposed deep neural network is trained using frequency data of the finite element model and real intact state and then is tested using frequency data of the real system. The proposed network is designed in two stages, namely, the pre-training classification based on deep auto-encoder and Softmax layer (first stage), and the re-training classification based on backpropagation algorithm for fine tuning of the network (second stage). The proposed method is validated using a lab-scale offshore jacket structure. The results show that the proposed method can learn features from the frequency data and achieve higher accuracy than other comparative methods.


2014 ◽  
Vol 501-504 ◽  
pp. 1238-1242
Author(s):  
Li Wang

Finite element model of the background tied-arch bridge was established and analyzed. Meanwhile, mechanical performance and stability of it under several kinds of simulate structural defects and damages were studied. Some typical damage and influence factors were presented in the beginning. Then, based on the finite element model, the distribution of suspender force corresponding to the simulated defects and failure was calculated respectively. At last, the first class stability safety factor under the combination load was calculated as well as the second class nonlinear stability safety factor under structural arch rib defect. Results of above calculation imply that, suspender forces gained a stronger sensitivity to vertical defect than to transverse defect. While, short suspenders were believed to be more sensitive to lineation defect than long ones according to calculation results. Additionally, secondary inner force of short suspenders was much more intensive than in long ones. The result also tells that lateral wind did bad to stability. Lift wind, contrarily, made a little positive contribution to structures in-plane stability. Simulated structural defects were supposed to aggravate the second class stability safety factor under geometric nonlinear condition.


2000 ◽  
Author(s):  
A. D. Yoder ◽  
R. N. Smith

Abstract The importance of predicting and reducing thermal expansion errors in workpieces is becoming greater as better precision machining processes are developed. An artificial neural network model to estimate the workpiece thermal expansion errors in real-time during precision machining operations is developed and compared with experimental results. A finite element model of workpiece thermal expansion has been created to predict expansions in a thin cylinder undergoing a turning process. The neural network has been trained using finite element model solutions over a range of conditions to allow for changing machining parameters. To realize “on-line” capability, the measurable values of heat flux into the workpiece, surface heat transfer coefficient, and tool location are used as inputs and the expansion as the output for the neural network. The estimations of the network are compared with experimental results from a turning process on a large diameter aluminum cylinder. There is reasonable agreement between measured and estimated expansions with an average error of 18%. The neural network has not been trained at the cutting conditions used during the experiment. The speed of the neural network estimation is much greater than the solution to the finite element model. The finite element model required over 15 minutes to solve on a Pentium 133Mhz computer. The neural network calculated the expansions easily at 1 Hz during the experiment on the same computer. With real-time estimation using measurable data, compensation can be made in the tool path to correct for these errors. The application of this method to precision machining processes has the capability of greatly reducing the error caused by workpiece thermal expansions.


2017 ◽  
Vol 17 (3) ◽  
pp. 135-144 ◽  
Author(s):  
Gaiyun He ◽  
Can Huang ◽  
Longzhen Guo ◽  
Guangming Sun ◽  
Dawei Zhang

AbstractThe relative positions between the four slide blocks vary with the movement of the table due to the geometric errors of the guide rail. Consequently, the additional load on the slide blocks is increased. A new method of error measurement and identification by using a self-designed stress test plate was presented. BP neural network model was used to establish the mapping between the stress of key measurement points on the test plate and the displacements of slide blocks. By measuring the stress, the relative displacements of slide blocks were obtained, from which the geometric errors of the guide rails were converted. Firstly, the finite element model was built to find the key measurement points of the test plate. Then the BP neural network was trained by using the samples extracted from the finite element model. The stress at the key measurement points were taken as the input and the relative displacements of the slide blocks were taken as the output. Finally, the geometric errors of the two guide rails were obtained according to the measured stress. The results show that the maximum difference between the measured geometric errors and the output of BP neural network was 5 μm. Therefore, the correctness and feasibility of the method were verified.


2013 ◽  
Vol 275-277 ◽  
pp. 1127-1131
Author(s):  
Ding Shi Li ◽  
Qing Tian Su ◽  
Yuan Wei Liu

Steel tied arch bridge with outward rib was adopted in Aixihu bridge in Nanchang city, in which steel girder width was 73 m. Outstanding features, such as large ratio of width to length, outward inclined ribs, four groups arrangement of spatial suspender existed in this bridge. Beam-column finite element model (FEM) and shell-beam FEM for the arch bridge are established respectively. The mechanical behaviors of the arch ribs and the girder analyzed by two different models are compared. The calculation results show that both beam-column FEM and shell-beam FEM can be used in the analyzing the mechanical behavior of arch ribs, while for the wide girder mechanical character analysis should not depend on beam-column FEM but shell-beam FEM.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
B. Asgari ◽  
S. A. Osman ◽  
A. Adnan

The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges.


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