The Vibration Reducing Performance Of The Large-span Double-layer Shell With Buckling Restrained Braces

In recent years,with the rapid development of large span spatial structure,the study of seismic performances of latticed shell structure is special important.As a result of the stability of Single-layer reticulated shell,more large span projects are designed to double-layer reticulated shell.There are a lot of practical engineering applications,such as Beijing Olympic Laoshan Bicycle Museum(The largest span double-spherical shell structure of China),double ellipsoid shell National Grand Theatre,Chongqing Olympic Sports Center Stadium,hyperbolic twisting double shell Comprehensive Museum Network of Beijing University of Physical Education.BRBs are a new system to avoid brace buckling,mainly composed by core steel component and restrain component around.While sustain axial force,the core component of BRBs can be yield completely and get energy dissipating through yield under tension and pressure.But thestatistics shows that,the BRB damping reseach and design are only limited by ordinary structures,such as frame structure,frame-shear system,bridge construction and so on.It is still on its primary stage in the damping research of large span structure.The applicability of BRBs used in double-layer reticulated shell is main discussed in this article。The mainly works in this paper as follows:(l)According to the double-layer Reticulated 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 static loads analysis and modal analysis,and studying the double-layer reticulated shell's vibration characteristics and grasping structure deformation,regular pattern of nodal displacement and nature frequency.The rules of brace arrangement are presented according to mechanical properties.(3)Imposing on the structure with 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)The calculation and analysis of the structure are analyzed under different seismic waves and different seismic peak acceleration.Compare both differences effects of damping.The damping effect of parametr is also studied,such as the rise to span ratio height of the structure and the BRBs' section.In addition,the dynamic response of double-cylindrical shell with BRBs is analyzed.