The Studies On Damage Detection Of Circular Arch Based On Strain Mode

Most of the engineering structures, when subjected to the natural disasters such as earthquake and typhoon or the action of the long-term fatigue loading and erosion, will be induced structures damages. The damage detection and identification of the damage location can help us carry on the real-time repair so as to reduce damage level and economic loss.In this paper, theoretical analysis, numerical simulation and experimental research on circular arch with different damages are introduced. A method of damage detection for circular arche is given by using natural frequencies, displacement mode, curvature mode and strain mode. The main works in this paper include four espects as follows:(1)The vibration-based methods of damage detection are reviewed and summarized. The background and development trend in this field are surveyed.(2) The theory of vibration of circular arch in the plane is suveyed. And the methods of damage detection which are based on displacement mode and strain mode are also summarized. The relationship between radial displacement in the mid plane and tengent strain in the exterior plane of circular arch is driven.(3) The circular arches with different damage locations and degree are simulated by using ANSYS code. The natural frequencies, displacement mode, curvature mode, and strain mode are obtained. These methods are also compared for fifferent damages. Compared to the detection methods by displacement mode and curvature mode, the detection method by strain mode is more sensitive to the damage changes.(4) The experimental study on viberation of circular arch is carried out. The feasibility and validity of the damage detection methods in this paper are testified by the experiments to the circular arch with different damage degree. The general relationship between strain mode and the damage degree of circular arch is studied, and some problems found in the tests are also analysed.