【摘要】 基于Harichandran-Vanmarcke相干函数模型和改进的Kanai-Tajimi过滤白噪声自谱模型,以及Amin-Ang非平稳化函数模型,采用MATLAB语言程序,引入快速傅里叶变换(FFT)算法,编制了基于Geodatis改进型谱表示法的考虑地震动空间变异性的非平稳人工加速度时程。分别采用线性加速度积分法和FFT变换频域积分法将加速度时程转化为位移时程作为地震动激励。运用双线性恢复力模型,引入ANSYS中的COMBIN40单元来模拟双肢薄壁墩墩顶、墩底塑性铰截面的材料非线性关系,同时,考虑桥墩大位移而导致的几何非线性,建立桥梁结构双重非线性有限元模型,得出高墩连续刚构桥在罕遇地震作用下的非线性受力特性和塑性铰截面的延性特性。其分析方法和结果对同类桥梁结构在罕遇地震动激励下的抗震设计与研究具有一定的参考价值。更多还原

【Abstract】 Based on Harichandran-Vanmarcke coherence function model,modified Kanai-Tajimi filtered white noise power spectrum model and Amin-Ang non-stationary function model,the Fast Fourier Transform(FFT) algorithm are adopted to compile the non-stationary Artificial acceleration time history with the spatial variation of seismic ground motions which is based on Geodatis-innovated spectral representation method by using program of MATLAB. A linear acceleration integral method and the FFT frequency-domain integral method are applied to transform acceleration time history to displacement time history respectively,which will be the ground motion excitations on the bridge structure. Importing the bilinear restoring force models,and using the Combin40 element in program ANSYS to simulate the nonlinear property of materials on plastic hinge sections in the pier top and pier bottom,simultaneously taking the geometrical nonlinearity due to large displacement of piers into account,the double nonlinear Finite Element Method model of the bridge has been set up,and the nonlinearity and ductility of the plastic hinge sections of the high-rise rigid frame bridges under rear earthquake has beenobtained. The approach and achievement represented in this paper have some certain significance as a reference for the rear earthquake-resistant design and research for other similar bridges.更多还原