Seismic Control Research Of Nonlinear Building Structure

There are many kinds of civil engineering structures such as reinforced concrete structures and steel structures and so on, and they all have strong nonlinear characteristics. In classics seismic design of structures, with the linearity and resilience presume, we can only analyze frequent earthquakes. But in major earthquakes phase, the calculating model of structures ought to be nonlinear. Structure control is one kind of promising means to structure seismic design. At the moment, control theory for the linear structure has already been developed very maturely. Yet it is still a difficult problem for seismic control of nonlinear structure. The research aimed mainly at nonlinear structure control means .The main research work consists of four aspects:1. Directly nonlinear control is applied to nonlinear structures. With introduction of nonlinear vibration control method into nonlinear structures, it is got as the preliminary research result to the application in the nonlinear structure vibration, and it has been established for nonlinear model to nonlinear structure vibration control system. The simulation result indicates that applying the nonlinear control method to the nonlinear vibration control is feasible, with smaller control force than general linear optimum control method to achieve the similar control effect, especially more remarkable under strong earthquakes.2. Through accurately feedback linearization, and with inverse system approach ,it can change from nonlinear structures to pseudo linear system to which traditional linear control theory could be applied. Research results show the means is superior to linear theory control method and the application field is extended.3. With neural network inverse system method which combining the neural network approach with inverse system approach, it is controlled for strong nonlinear building vibration which is difficult to set up model. From this research, it makes known that the approach have both merits of inverse system approach and that of neural network approach, and it is usable for seismic control of complex nonlinear structures. Original structures may be transformed into superimpose of linear module and nonlinear module in order to decrease difficulty in building model.4. With predictive control approach based on neural network, nonlinear prediction control was implemented for strong nonlinear structure vibration. The comparison research has been made between the effect of linear control method and that of active predict control method by using neural network. It can be seen through the neural network predict control that structure displacement is under effective control, which shows that the effect of this kind of control method is remarkable.