Time Domain Simultaneous Identification Of Structural Parameters And Loads

Structural parameter identification and external load identification have long been both independent development in structural dynamics research. Most of the traditional structure parameter identification methods require the input load, or do the white noise assumption on the input load. These methods only identify the structural parameters; do not identifying the external load. These load identification methods do not take into account the structural model error, but require prior identification or correction of structural parameters. With the progress of science and technology and the development of productive forces, structure is becoming more complicated. People find in many circumstances, structural parameter. identification problems and load identification problems often exist in one structural problem. For example, structural model for load identification have changed due to structural damage, or the boundary conditions changing. The external load for structural parameters identification many cases is impossible to accurately measure. It is important and very real engineering applications to structural physical parameters identification and external load identification with unknown input. Recognition results are of great significance to structural dynamic design, health monitoring, and vibration control.Based on the above-mentioned engineering background, this paper focuses on simultaneous identification of structural parameters and loads with unknown input. First summarize the of structural parameters identification with the known input circumstances and load identification theory with the known structural parameters. Then discuss the existing composite inversion methods. And then discuss the influence of the structure of the model error and measurement noise to time-domain load identification accuracy. Verify the theoretical analysis through a numerical example. Finally the further development of existing composite inversion method, asked a step-by-step iterative composite inversion method. Effectively improve the calculation accuracy and computational efficiency for load identification by the precise integration modeling, using the regularization method to deal with the ill-posedness of force identification problem; in order to avoid the traditional nonlinear optimization method easy to fall into local optimal solution in the structure of the parameter identification process, The genetic algorithm is used to the structural parameters identification by measurement of time-domain acceleration response. Comparative analysis of different numerical examples, verify the validity of the method.