DAMAGE AND DYNAMIC CHARACTERISTICS ANALYSIS OF A SOLID STRUCTURE PAGODA

In order to study the dynamical characteristics and structure damage of Ceshi Pagoda in Xingjiao Temple, which is one of the world heritage of culture buildings, we conducted in-situ dynamical test by super low frequency dynamical test system. Stimulated by a random vibration, the velocity response data in the top of each floor is gathered after wave filtering. By self spectral and inter spectral analysis with integral transform, the first and second stage of frequencies and vibration modes are acquired along the horizontal direction. A finite element model of Ceshi Pagoda is constructed, based on the measured data. The vibration characteristics are calculated for decreasing elastic modulus. Then they are contrasted with the test results.The structure damage analysis is performed, based on Improvement Shape Method for damage parameter identification. The results show that the first and the second stage vibration frequencies are close to each other along NS and EW direction. The first stage vibration mode is bending type, and the second is bending and shearing type. The effective elastic modulus of Ceshi pagoda is much smaller than that of a masonry structure in good conditions. Therefore, the damage of masonry pagodas can be recognized from the results of dynamical test and numerical calculation, after the elastic modulus of complete masonry structures is defined.