METHOD FOR ESTIMATING DYNAMIC PARAMETERS OF STRUCTURE, MAKING USE OF MORLET WAVELET TRANSFORM

摘要

PURPOSE: A method for estimating dynamic parameters of a structure, making use of Morlet wavelet transform is provided to estimate the natural frequency, the damping rate, and the vibration mode shape through one-time Morlet wavelet transform. CONSTITUTION: A method for estimating dynamic parameters of a structure, making use of Morlet wavelet transform comprises steps of measuring the frequency at a specified position of the structure, making use of a measuring instrument(S1); abstracting an acceleration time history signal from the measured signal(S2); filtering the acceleration time history signal and abstracting an acceleration time history signal to the time zone of an interested area(S3); finding a ridge constant through Morlet wavelet transform of the acceleration time history signal of the time zone of the interested area and estimating the natural frequency of the structure by the founded ridge constant(S4); taking a natural logarithm to the magnitude of a wavelet coefficient to the natural frequency and estimating the damping rate of the structure through the gradient of a variable wave form by time(S5); and estimating the vibration mode shape of the structure, making use of a difference of argument to a reference point, and the amplitude ratio from the ratio of the wavelet coefficient magnitude of the identical time(S6).