Three Pagodas Concrete Cable-stayed Bridge Multiscale Modeling And Analysis Of Local Damage

With the development of large-scale bridge, the safety requirement of large-scale bridge structure becomes higher and higher, and we need to consider more and more internal and external factors on the impact of cable-stayed bridges. During the process the key issue is that we need an accurate FEM model which takes the characteristics of the whole structure and part details into account. It is very necessary for us. Therefore, the main contents of the study are: the study of the multi-point constraint with multi-scale model and its application, which will take the part details and the overall characteristics into account with the requirements of long-span bridges for structural damage assessment. The areas addressed in the research are listed as follows:1. Systemically introduced the developments and trends of cable-stayed bridge, and narrated the means of multi-scale modeling under long-span structures at present;2. Established an ANSYS model of the Bridge of Dongtinghu. In the proposed modeling method, the "large-scale" modeling is adopted for the global structure and the "small-scale" modeling is adopted for the critical locations in the process, then programmed and adjusted stress of cable-stayed bridge respectively;3. Analyzed local stress of the anchorage zone, obtained the stress characteristics and conditions of this zone;4. Edited ANSYS macro-program and generated singular finite element on the crack-tip of the bottom of the BEAM, and solved the stress intensity factor;5. Discussed the influence of the damage of the cable to the natural frequencies and other cables;6. Made use of Monte Carlo principle to simulate traffic volume of flow and deduced the cable of 14^th's fatigue reliability in axial stress.