The Research On Vibration Reducing Performance Of Single Layer Ellipse Lattice Shell Installed Buckling Restrained Braces

Single layer ellipse lattice shell consists of two hemi-sphere shell and a cylindrical shell, such shell can be applied to many types building such as stadium meeting&exhibition hall and industry storage etc. Those buildings will be demanded more in our nation with economy development. But earthquakes happen often in the scope of the land we live, and high intensity area distribute widely, so economics and safety of long spatial shell can hard be meet if we adopt traditional anti-seismic theory during the course of design.It is the Buckling Restrained Braces (abbreviation: BRBs)--a type of component dissipating energy when yielding that is applied to single layer shell to make vibration reducing system, corresponding principles of BRBs' location and appraisal indexes of vibration reducing effect are put forward in the paper based on the obtained mechanics performance of the shell, and concrete schemes of BRBs' location are designed. First of all, a program is made accord to the types of combination shell and members connection law to realize automatic modeling, grids calculation and members' cross-section selection are derived from the regulation of approximate equivalence of stable bearing capability, to know clearly the shell deformation mode and nodes' displacement distribution law is by means of static and dynamics analysis on the shell; to assure the shell and the vibration reducing system can be compared with each other such pre-conditions should be prepared, which are the principle of equivalent cross-section area when BRBs substitute to members, statics equivalence between the shell and the vibration reducing system, and approximate equivalence of frequencies when free vibration happens. Subsequently, seismic spectrum analysis during elastic phase and time-history analysis when plastic strain is produced in BRBs of the vibration reducing system, to obtain nodes' displacement reducing distribution, progressive yielding and energy dissipating of BRBs, and give appraisal on performance of vibration reducing systems by comparison with each other; To focus on engineering practices, Multi-dimension Earthquake Excitation, Height to span ratio and Span are calculated respectively as influencing parameters, so as to obtain such parameters' effect on performance of those vibration reducing system, some theory analysis is finished and pieces of concrete suggestion are concluded in the end.Principles of BRBs' location put forward in this paper can be applied tovibration reducing analysis of other types combination single layer shell, some conclusions drew from single layer ellipse lattice shell can be used in engineering practices, or support progressive study on vibration reducing of single layer shell.