Damage identification method based on structural dynamic characteristics and strain measurements

Abstract

More and more large span structures have been built or are being built and their health is concerned about by civil engineers and investors, which arises to the problem of studying on several damage identification methods to give estimation on the health of the structure and the identification on damage location and damage degree. The damage identification methods in civil engineering are mostly based on dynamic characteristics, which have difficulties when applied to practical structures. Meanwhile, the strains of the structural important elements can give more exactly and more directly information for damage identification on damage location and damage degree. The information fusion for acceleration sensors and strain sensors is used for making a strategic decision on damage identification and the Dempster-Shafer evidence theory is used as the information fusion strategic decision, in which the strategic decision information fusion is a method to give the final decision based on the decision made by each kind of sensors according to some principle and some synthesized evaluation, that is, the final damage identification results are given based on the damage identification results using the structural dynamic characteristics and strain measurements. In addition, a finite element model of large span space shell structure is built and several damage cases of it are simulated, in the example, the structural dynamic characteristics damage index and strain measurements damage index are used to give the damage identification results, combining which the final damage identification result by strategic decision fusion is given too, while the method presented in the paper is proofed to be reliable and effective according to comparing the three kinds of damage identification results mentioned above.