The Vibration Reducing Performance Of The Single-layer Landing Oval Shell With Buckling Restrained Braces

The Buckling-Restrained Braces (BRBs) is a new development of vibration reduction brace element in recent years. The nuclear steel brace can reach full yield under tension and pressure. It takes on better ductility and has the stable and full hysteresis loop. BRBs with low yield stress can dissipate energy on the small displacement.Currently, BRBs has been accepted and used in Japan and the United States. It is studied more about BRBs applied to multi-story and tall buildings, and the study on BRBs used in the long-span spatial shell structures is just beginning. Lattice shell structure usually has larger rigidity under static loads, but when the span becomes larger, it may generate big response under the earthquake loads. Therefore, vibration reduction study on the lattice shell is quite necessary. And long-span spatial shell structures are usually representative and important buildings, the seismic performance directly relates to the people's lives and national economic security, so the design of the lattice shell's vibration reduction has very important significance.Due to the oval shell's shape and the characteristics of the structure, there are a lot of practical engineering applications, such as the Shanghai Science and Technology Museum, Wenling Jinping Park door, and also double ellipsoid shell National Grand Theatre. This paper will discuss about BRBs applied to the single-layer oval shell structure in the application of damping.Main activities include the following:(1)According to the oval shell's composition and bar connecting law to programming, using the finite element software ANSYS to automate modeling.The BRB element is assumed the ideal elasto-plastic model.(2)Doing the oval shell's static loads analysis and modal analysis, and studying the oval shell's vibration characteristics and the changes of the stiffness, stability under the static loads according to the results of static loads analysis and vibration analysis.(3)Imposing on the structure with one-dimension and three-dimension seismic waves and doing the dynamic time-history analysis to get the nodal displacements, the BRBs' yield progress and energy situation, then evaluate the performance of the BRBs.(4) According to the analysis of dynamic time-history on the oval shell structure, doing the parametric analysis, such as the dyadic height of the structure, the BRBs' section size, to get the valuable suggestions for the BRBs' application in the structure of the long-span spatial shell.