The Study Of Simulation And Experiment For Nonlinear Structural Vibration Based On Bouc-Wen Model

Most of the structures will exhibit nonlinear behaviors from the elastic stage to the plastic stage under the effect of strong earthquake and wind loads. Therefore it is very important to study the theory and experiment of the nonlinear vibration for the structures, which has an important theoretical and practical value for the development of structures in civil engineering.In the fields of structural dynamics and structural control, experimental verification is undoubtedly necessary for the theoretical and numerical study. However, most of the current model tests only considered the linear behavior of the structure. So how to construct a model of structural nonlinear vibration becomes a research hotspot of civil engineering. Regarding structural nonlinear vibration tests, especially relate to material nonlinearity, the tests will often lead to structural yield even damage. Thus the structure is unable to return to the initial state to repeat the tests. A repeatable test platform for structural nonlinear vibration tests is important for the corresponding studies so that different theories and algorithms can be analyzed. The paper carried out the following works:1) A rotary viscous damper is used to simulate the plastic hinge of rigid frame. This damper can be controlled by adjusting the torque adjustment bracket at the bottom of the damper. The test is carried out on the torsion testing machine for the rotary viscous damper. Torque-angle testing data is measured under different damping conditions and different speeds. The mechanical characteristics of the damper is analyzed.2) Based on the Bouc-Wen model, the model parameters are identified using Simulink in Matlab depending on the torque-angle hysteresis curves that are obtained from the experiment. According to the model parameters obtained under various conditions, the effect law of the hysteresis curves is discussed considering the change of the parameters in the model. The model parameter variation under different dampings and speeds of the rotary viscous damper is determined through the analysis, which ultimately determines the mechanical model of the damper.3) A one-story nonlinear vibration test model is constructed with the viscous dampers installed on the nodes of a one-story rigid frame structure. Moreover the theoretical model of the structure is build based on the Bouc-Wen model and structural dynamics to analyze the structure under different damping conditions. Then the accuracy of the simulation results is verified through the experiment.4) A multi-story nonlinear vibration test model is constructed with the viscous dampers installed on the nodes of a three-story rigid frame structure. Different locations of the rotary viscous dampers in the structure and different dampers of the dampers are studied and analyzed through the experiment.