A weighted balance evidence theory for structural multiple damage localization

In order to identify structural multiple damage locations, an improved evidence theory is proposed in this paper. First, the changes of frequencies and mode shapes are regarded as two different information sources, and local decisions can be obtained by using the multiple damage location assurance criterion (MDLAC) method and the frequency change damage detection method (FCDDM), respectively. Then, the local decisions are sent to a fusion center. In the fusion center, the evidence fusion technique is applied to integrate those local decisions and acquire a global decision. It is considered that the multiple evidences from different sources of different importance or reliability are not equally important when they are combined according to evidence theory, which is seldom considered in the existent combination methods. A new approach, i.e. weighted balance evidence theory (WBET), is presented to solve this problem. In order to compare the identification results under different weight coefficients, a multi-damage identification index is proposed. The simulation results demonstrate that the excellent performance of the proposed method to identify multiple damage sites as compared with the MDLAC method and the FCDDM method. In addition, analysis indicates that basic evidenced combination is a particular case of the WBET method under certain condition. (c) 2006 Elsevier B.V. All rights reserved.