Study On Indices Of The Damage Location On The Concrete Arch Dam

It is of great importance to study the damage detection of concrete dam. During the designed effective time in use, it is very possible that there are many kinds of breakage. If they are not detected in time and freely expand, they would affect the normal designed function of the water and electricity station to play, even destroy the dam and the station and consequently result in the loss of life and wealth of the lower reach. So it is quite necessary to conduct a safety monitoring and damage analysis of the dam.This thesis mainly probes into the applicability of various damage indices to the dam when there is any damage (for example a crack).The first step is to build a concrete model dam and carved it up into net. After measuring the normal modal parameters (chiefly the natural frequency of vibration and modal vector at nodes), the dam is loaded three times to simulate the damage of different degree. And the modal parameters in those damaged cases are measured.Then a numerical model of the dam is established in the software ANSYS. In ANSYS the numerical model is carved up into net and the modal parameters are calculated under the undamaged condition and three degrees of damaged condition. Finally different modal parameters are used in the damaged indices and thus we can compare their effects on the crack. It is turned out that the beta method and MSC method have better effects.At last the beta method and MSC method are respectively applied to the modal parameters of three damaged condition of the dam' s experimental model and their ability to find out the experimental model's damaged location is compared . The three-dimensional picture that shows the recognizing results by these two methods of the experimental modal indicates that the beta method has a better effect. And the MSC method almost can't locate where the dam' s experimental model is damaged due toits weak capability of handling noise.