DFT加速及其在非平稳随机振动计算中的应用  

DFT Accelaration and Its Application in Non stationary Random Vibration Calculation

作　　者：陈奎孚[1] 张森文[2] 

机构地区：[1]中国农业大学东校区工程基础科学部 [2]暨南大学应用力学研究所

出　　处：《振动工程学报》1999年第1期91-96,共6页Journal of Vibration Engineering

基　　金：国家自然科学基金

摘　　要：为了降低非平稳随机振动的计算量,采用了离散付立叶变换和线性调频Z变换(CZT)。针对工程常用的演变随机激励,将激励的包络和功率谱函数分开处理,这可使理论计算与实测数据相结合,从而克服阻尼难以确定的难点。算例表明,分段CZT较普通CZT可节约1/3计算量;而平稳的功率谱与包络分开处理也大大节约了计算量并易于工程实际应用。In order to reduce the burden in calculation of nonstationary random response,the Discret Fourier Transform (DFT) and Chirp Z Transform (CZT) were adoped.Concerning the evolutionary random excitation frequently used in engineering,the nonstationary part (envelop) and the stationery one (spectrum) were processed independently to lessen work.Furthermore,it could build a bridge between theory and measurement,hence the difficulty to handle damping could be avoided.The simulation shows that 1/3 of the calculation amount can be saved in sectional CZT method.The spectrum and envelop splitting technique not only can reduce the computation burden,but also is practicable in engineering application.

关 键 词：随机振动 瞬态响应 非平稳 DFT加速 CZT 

分 类 号：O324[理学—一般力学与力学基础] TN911.1[理学—力学]