【摘要】 以钢框架结构为研究对象,采用基于环境激励的时间序列法、随机子空间法、随机减量法和NExT法对框架结构进行损伤模态频率识别,分析研究这四种方法模态频率识别效果。本算例计算结果表明各种方法识别精度存在差异,随机子空间法和随机减量法对一阶频率识别精度高于其他两种方法。应根据具体识别需要,优选一种或多种方法进行工程结构模态识别。各种方法频率变化率可用于初步或粗略损伤判别。更多还原

【Abstract】 Steel frame structure is studied. Four time domain identification methods based on ambient excitation are adopted to identify modal frequency and they are time series method, stochastic subspace method, random decrement technique and natural excitation technique. Identification precision is discussed. Results show that identification precisions of four methods are different. Precisions of stochastic subspace method and random decrement technique to first order frequency are high. According to identification demands, one or several methods should be adopted to practical engineering structure. Frequency change ratio from discussed methods can be applied to preliminary and coarse damage identification.更多还原