Research On Seismic Control Of Double-layer Spherical Reticulated Shell With Replaceable Piezoelectric Friction Dampers

Reticulated shells are graceful and aesthetically pleasing long-span structures that have been widely constructed throughout the world. The trend in using reticulated shells has been towards higher, larger and more elaborated structural configurations. Such steel structures typically have very low global stiffness and damping, which can result in large vibration and affect application and safty of the structures. As a result, new challenges have arisen to ensure the safety and performance for these shell structures when subjected to strong earthquakes and severe winds. Vibration control methods are attractive because improved performance can be achieved without changing the structural form, primarily by increasing structural damping. Friction damper has been widely applied in engineering practice as a seismic device with good performance. In order to improve the performance of friction damper, the concept of semi-active control was introduced into the damper design. And the piezoelectric friction damper is a combination of the merits of piezoelectric actuators and the friction damper, which can manage the real-time control force of replaceable bar-type damper to achieve semi-active control.Based on the experience on the manufacture of friction damper, this paper designs a piezoelectric friction bar-type damper. And mechanical performance and parameter impact of the damper are researched to achieve the basic structure and mechanical model. In view of the mechanical model, the parameter analysis of the proposed Bouc-wen model which obtains the impact on hysteresis curves of each parameter is simplified. Then the pseudo friction and the pseudo viscosity restoring force of the piezoelectric friction bar-type damper are simulated. Afterwards, the proposed Bouc-wen model is applied for seismic analysis of an example so that the seismic effect of the damper is very well.Computational models of pyramid double-layer spherical reticulated shell are developed. Then the self-vibration of the uncontrolled and controlled structure are researched to learn the laws of the self-vibration characteristics. And the two structures are analyzed under three-direction earthquake by the time-history analysis method to study the self-vibration characteristics and the dynamic response on the contrast of the uncontrolled and controlled structure. The results show that the damper can significantly reduce the responses of the controlled structure which is seismic.To learn dynamic characteristics of the double-layer spherical reticulated shell with replaceable piezoelectric friction dampers better, this paper conducts a parametric analysis including the stiffness of damper, the earthquake acceleration peak, different earthquake, equivalent damping ratio and the initial defects. The results of the research are as follows. Appropriate stiffness of damper will improve the energy dissipation. Influence on the dynamic responses of shell shrugs off the earthquake acceleration peak. And the NOR earchquake wave is most harmful to the structure. The increase of equivalent damping ratio will improve the seismic effect. And initial imperfection of the structure can not be ignored.However, the intelligent bar-type damper control method is effective for vibration control, but there is a great distance from practical application and it’s just a beginning. In future, based on the simplified parameters analysis on this paper, the proposed Bouc-wen model parameter identification of the designed mechanical model should be more rigorous. And the range of parameter analysis should be expanded in order to obtain more accurate seismic law. Then the experiment research of the designed damper will be tested to verify its theoretical mechanical performance and to lay the foundation for the practical engineering applications.