【关键词】 地展动时程; 非平称; 非线性; 频谱分析; 时频分析; 瞬时频率; 希尔伯特-黄变换(HHT); 经验模态分解(EMD); 本征模态函数(IMF); Hilbert谱; Fourier变换; Fourier谱; 小波变换; 小波谱; 自回归模型; 线性SDOF体系; 双线性SDOF体系; 场地液化
【Key words】 ground motion time history; non-stationarity; non-linearity; spectra analysis; time-frequency analysis; instantaneous frequency; Hilbert-Huang transform (HHT); empirical mode decomposition (EMD); intrinsic mode function (IMF); Hilbert spectrnm; Fourier transform; Fourier spectrum; wavelet transform; wavelet spectrum; auto-regressive model; linear SDOF system; bilinear SDOF system; site liquefaction.
(建议：英语作文)