Study On Vibration Control Of Replaced Damping Poles In Double-layer Lattice Spherical Shells

The spatial reticulated shell structures become more popular in nowadays, so it is in dire need of an effectual anti-earthquake measurement to control the vibration of reticulated shell structures. An anti-earthquake measurement called replaced damping-poles method is a valid way. It reduces the seismic response of structure by adding the damping and dissipating the vibration energy of the structure. Because this devise is effectual,simply and the components are cheap, the replaced damping-poles has a broad application foreground. Because of the particularity of the reticulated shell structures fixed with replaced damping-poles and the faultiness of the study about this filed (only finish some numerical analysis and do few pseudo-dynamic tests in reticulated shell cylinder), it is necessary to give plenty numerical simulation of replaced damping-poles in sphere reticulated shell.In this paper, the research object is the double layers keiwitt reticulated shell structures which span 40m. Uncontrolled reticulated shell structure and some other shell structures with replaced damping-poles are used to build up different three-dimensional modals by ANSYS(?) program—a finite element method. ANSYS(?) program is also used to analyze the elastic dynamic time history analysis and whole-course analysis of EI-Centro seismic wave at usual level and unusual level. The results are obtained after analysis and comparing. The main research contents are stated as follows:Study of replaced damping-poles'position:Double layers reticulated shell contains too many poles, different replaced damping-poles'positions create different controlled effects. Base on the different poles' place, this paper chooses fifteen replaced positions to work over. Compare each response, author obtain the position rule of the controlled method.Research on controlled reticulated shells with some parameters:In order to realize the controlled effect of the replaced damping-poles method, this paper chooses several parameterizations to study, like damping poles' damp coefficient, damping poles'rigidity, peak value of seismic wave's acceleration, span of reticulated shells and so on, illustrate the infection on effect of the controlled method.Research on dynamic failure of reticulated shells:For finding out the infection of the controlled method on the critical load, this paper does a whole-analysis for uncontrolled shell and controlled shell under dynamic loads. According to the index response of structure, understand the failure mechanism of reticulated shells. Then compare the failure loads, know the infection of the controlled method on critical load of double layers reticulated shell.The research result illustrates that the replaced damping-poles method work effectively in reducing the response of double layers keiwitt reticulated shell structures under EI-Centro seismic wave. At usual and unusual level, the replaced damping-poles act fine without exception, then the seismic fortification ability of reticulated shell structures is markedly promoted. The result also show that the replacing dealing does not debase the stability of the structures, the dynamical critical load doesn't fall obviously. The analysis proves that the replaced damping-poles method advisable, it leads a right way in controlling response of reticulated shell structures under seismic wave.