1、1450 单词， 7800 英文字符， 2000 汉字 出处： Bayraktar A, Sevim B, Altuniik A C. Finite element model updating effects on nonlinear seismic response of arch damreservoirfoundation systemsJ. Finite Elements in Analysis & Design, 2011, 47(2):85-97. 毕业设 计 外文翻译 题 目 专 业 水利水电工程 班 级 学 生 指导教师 2014 年 1 Finite element mod
2、el updating effects on nonlinear seismic response of arch damreservoirfoundation systems A Bayraktar， B Sevim， AC Altuniik Abstract This is paper investigates the effects of finite element model updating on nonlinear seismic response of arch damreservoirfoundation systems. The highest arch dam in Tu
3、rkey named Burke is selected for the numerical and experimental applications. Firstly, 3D finite element model of Berk Dam was constituted using ANSYS software. In the analytical modeling, arch damreservoirfoundation interaction is represented by Lagrangian approach. Then ambient vibration tests wer
4、e conducted to dam for four days, and experimental dynamic characteristics were estimated using an Enhanced Frequency Domain Decomposition technique. Experimental characteristics are compared with those of analytical obtained by the linear finite element analysis of the coupled system. Good agreemen
5、t between mode shapes is observed during this comparison, though natural frequencies disagree by 1520%. The linear finite element model of Berk Dam was updated by adjusting the material properties of the dam and foundation. By introducing the DruckerPrager damage criterion, the updated linear finite
6、 element model was extended into a nonlinear model. Nonlinear seismic behavior of Berk Dam was determined considering the acceleration record of Adana-Ceyhan, Turkey, earthquake in 1998 that occurred near the arch dam region. It is highlighted that the finite element model updating provides a signif
7、icant influence on the nonlinear seismic response of arch dams. Keywords Ambient； vibration； testing； arch dam； dynamic characteristics； nonlinear； seismic； response； finite element model updating； damreservoirfoundation interaction 1 Introduction Arch dams are one of the most important engineering
8、structures to provide energy. They are curved in plan and possibly in elevation, in addition they transmit a 2 large portion of the water pressure, utilizing the compressive strength of its concrete material. So they are built using little volume of concrete comparing to gravity dams, and they have
9、thin cross section. Therefore, arch dams are required sophisticated engineering knowledge to design and construction. Researchers have done many theoretical studies about dynamic behaviors of arch dams from past to present. Since the arch dams carry loads to in part by transmitting them through arch
10、 action to the abutments, and it is in contact with a foundation rock extending over the dam height, the effects of damfoundation rock interaction can be important in the earth- quake responses of arch dams. The other important effect on the arch dams is the reservoir. Reservoirs considerably affect
11、 seismic response of dams during earthquakes. Three approaches are used to consider the reservoir effects in the analyses: Westergard, Euler, and Lagrangian approach. In Westergard approach, it is considered that a vibrated mass dispersion with the dam, which is similar to being hydrodynamic effect
12、dispersion towards the dam upstream face. In Eulerian approach, the displacements are the variables in the structure； the pressures are the variables in the fluid. However, in Lagrangian approach, the displacements are the variables in both the fluid and the structure. So, there is no need of any ex
13、tra interface equations in Lagrangian approaches. For that reason, compatibility and equilibrium are automatically satisfied at the nodes along the interfaces between fluid and structure. Linear earthquake analysis of concrete arch dams, conducted to either in the evaluation of an existing dam or in
14、 the design of a new one, typically shows large tensile stresses when the ground motion employed represents strong shaking. Therefore, the nonlinear procedures are required to assess the seismic responses concrete arch dams in earthquake-prone areas. The earthquake design of concrete arch dams is a
15、very important problem, especially since failure of the structure could result in major loss of life. An integral part of any design process is the analytical technique that is used to obtain design values such as maximum stresses and displacements of the dam under various load conditions. The resul
16、ts of such an analysis can be used by the engineer to evaluate the adequacy of the design of the dam and to make appropriate modifications if needed. If the design is incorrect, or does not meet the required specifications, improvements to the design must be made. Therefore, a 3D finite element mode
17、l of the arch dams considering damreservoirfoundation interaction must be constituted truly. A realistic 3D finite element model can be checked by using an experimental modal behavior. The experimental modal behavior of an arch dam is related to its dynamic characteristics, such as natural frequencies, mode shapes, and damping ratios. One of the important inspections is to apply ambient vibration tests to existing dams to determine their dynamic characteristics. This method is called as
