基于区间摄动的不确定非线性结构动力学模型修正方法研究

An interval approach for model updating of a nonlinear structure with uncertain parameters using the first-order perturbation analysis of the time-domain dynamic response was proposed. The perturbation method was used to decompose the uncertain structural parameters into parameter interval mean and interval radius, and they were respectively regarded as the parameters to be corrected for two-step deterministic model updating. The optimization function for interval model modification was established to modify the interval mean and radius on the basis. A two-story rigid frame structure and a nonlinear cantilever beam were taken as the objectives of simulation. A uniformly distributed sampling method was used to construct the parameter samples, and two nonlinear forms including cubic nonlinearity and piecewise nonlinearity were simulated. The simulation results show that the convergence efficiency of the parameters and the accuracy of the updating were very high, and the updated time-domain response interval can reflect the interval characteristics of the test data. These results demonstrate that the perturbation method is an effective method for uncertain nonlinear structural model updating.