| When encountering natural disasters such as strong earthquake,the safety of engineering structure will be seriously threatened,so it is very important to grasp the performance of the structure in real time.Structural health monitoring has been widely used as the most mainstream means at present,which has become a necessary way to evaluate the safety process.However,in the actual health monitoring of the structure,it is usually necessary to real-time monitor and obtain the position and action strength of the load on the structure,and then judge whether the structure is damaged,so it is necessary to identify the load on the structure.In order to identify the load acting on the structure,it is the key to determine the feasible identification method.Many scholars at home and abroad have carried out a lot of research in the field of load identification technology.However,there is little research on the identification of random earthquake loads,and there is a big gap in this area.Based on the Kalman filter theory,this paper uses the response of the structure(acceleration,velocity,displacement and so on)to reverse and identify the seismic load,and tries to identify the stationary and non-stationary random seismic load acting on linear structure and non-linear structure,and compares the theoretical derivation and numerical simulation,and summarizes the identification law.According to the process of earthquake load identification,the work of this paper is mainly divided into the following aspects:(1)Simulation of random ground motion.Before the identification research,the selection of ground motion is the premise of this work.In engineering,the random earthquake model equation is usually used to simulate the random earthquake ground motion as the ground motion input.This paper compares and selects the oujinping random earthquake model equation to simulate the random earthquake action.In the theoretical part,the state space equation of the earthquake model is derived and compared with the structural model Combination of equations.(2)Determination of Kalman filter identification method.In this paper,Kalman filter method is selected as the identification method of random ground motion load.According to the characteristics of different structural models,according to the received ground motion load,based on the continuous Kalman filter theory and extended Kalman filter theory,the identification formula is deduced and the model ground motion load is identified,and the targeted identification method is summarized.(3)Load identification under different structural models.In order to discuss the identification of the Kalman filter method in linear structure and in nonlinear structure,the linear structure model and the nonlinear structure model are established respectively,and the parameters of the nonlinear model are compared and analyzed.Finally,the seismic load identification results under different structures are compared. |
