基于改进证据理论的结构损伤识别研究

摘要

Combining the information fusion technique and the application background of damage detection of civil engineering structures,a new evidence theory combination method was proposed.By introducing the concept of evidence ullage,the combining rule of the evidence theory was extended and improved,the calculation formulas for two important parameters including ullage function and tendency factor were built.The new combining rule was not only capable of covering Dempster combining method,but also capable of solving problems of evidence conflict and evidence compatible brought by the multi-source uncertain information.Therefore,compared with the traditional evidence combination method,the new combining rule was more suitable for engineering application.A single-span 3-story spatial truss structure model was used to conduct damage detecting tests under various operation conditions.The test results indicated that the proposed damage detection method based on the improved evidence theory can make full use of the multi-source uncertain information,effectively suppress the damage false positive rate,and improve the correctness and reliability of the damage detection results.%结合信息融合技术和土木工程结构损伤识别的应用背景,提出了一种新的证据理论组合方法.该方法基于证据损耗的观点,对证据理论组合规则进行了扩展和改进,建立了损耗函数和倾向因子两个重要参数的计算公式.新的组合规则涵盖了原Dempster组合方法,能够有效处理多源不确定信息所带来的证据冲突与证据兼容问题,具有更好的工程适用性.对1个3层单跨的空间杆系模型结构进行了多种工况下的损伤识别试验,试验结果表明,基于改进证据理论的损伤识别方法能够充分利用多源不确定性信息,有效抑制损伤误判率,提高损伤识别结果的准确性和可靠性.