Abstract:Research purposes: It has significant engineering value and research meaning to do research on intelligent diagnosis methods of a hybrid girder cable - stayed bridge. Taking Tianjin Hebei Street hybrid girder cable - stayed bridge as the engineering background, based on artificial neural networks, the method of hierarchical damage identification which is suitable to hybrid girder cable - stayed bridge is presented: the damaged substructure and damaged steel girder substructural components can be detected by using Probablistic Neural Network ( PNN) and Radial Basis Function ( RBF) Neural Network individually. Furthermore,an combined static and dynamic damage sensitive index which is suitable in the second step is presented,a RBF Neural Network model is constituted and used to simulate three damage conditions,i. e. single damage and double or three damages which occurred simultaneously.
Research conclusions: The identification results show that: ( 1) The proposed hierarchical damage identification method has a identified precision and efficiency,it is suitable to intelligent diagnosis process of hybrid girder cable - stayed bridges. ( 2) The combined static - dynamic damage identification index is also sensitive to cable - stayed hybrid girder bridges. ( 3) The identified precision for single damage cases is nearly to 100% . ( 4) For double and triple damage cases individually,the identified precision is nearly to 82. 61% and 78. 3% .
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