Abstract:
According to the hysteretic damping model based on a complex damping model, the Laplace equation of motion of the improved hysteretic damping model in a complex domain and the corresponding time domain equation of motion are established. The improved hysteretic damping model overcomes the time-domain divergence of the complex damping model and can ensure that damped natural frequency decreases with the increase of a loss factor. Combined with the recognition method of external excitation accelerations and the characteristics of the improved hysteretic damping time-domain motion equation, the time-domain calculation methods based on Fourier transform and Hilbert Huang transform are proposed, respectively. The analysis results of the cases show that the time-domain calculation method based on Fourier transform is realized in a global process, the structure dynamic response can be calculated at any time although its computation cost is large. The time-domain calculation method based on Hilbert Huang transform is time-domain step-by-step method, which has a small amount of calculation and a wider range of application though the calculation error is not easy to estimate.