The Dynamic Elastic-plastic Analysis Of The Single-layer Elliptical Shell With BRB

There were many studies on the statec performance of common types of retiulated shells, such as sphere, cylinder, elliptic paraboloid, hyperbolic paraboloid and so on, and many scholars have conducted in-depth analysis and discussion on the dynamic elastic-plastic analysis of the whole process of strategy, ideas and implementation methods. While there is little systematic study for ellipsoid shell. Because of ellipsoid shell's shape and structural characteristics, there are already many practical engineering applications, such as shanghai technological museum, Wenling Jinping Park Gate and double ellipsoid shell National Grand Theatre. This paper reviews the development and current research of single-layer dome structure firstly, then, analysising the dynamic performance of the single-layer ellipsoid reticulated shell comprehensively through the nonliner finite element method.By analyzing the geometric parameters, the Schwedler ellipsoid single-layer reticulated shell's dynamic performance was studied, and ansysing the relationship between the dynamic elastic-plastic of the structure and parameters such as short-to-span, span ratio,the initial defects and so on. Under strong ground motions the BRB to this type of reticulated shell structure's influence which dynamic performance and failure modes were investigated importantly.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.Main activities include the following:(1)According to the ellipsoid 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 ellipsoid shell's static loads analysis and modal analysis, and studying the ellipsoid 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 elastic analysis and elastic-plastic analysis. Investigate the shell's seismic response and seismic performance which rods at the elastic stage and into the plastic stage.(4)According to the analysis of dynamic elastic-plastic, study the influence which the structure of the initial defects to the ellipsoid shell's dynamic performance, and investigate the damping effect of the BRB's to ellipsoid shell to get the valuable suggestions for the BRBs'application in the structure of the long-span spatial shell. The results show that, the shell's rods reached plastic at the time of strong earthuake, and changed with the strength of earthquake scceleration, the number of yield rods are changed. The results of shell elasto-plastic seismic have very big difference between two condition which considering the material nonlinearity or not. The buckling-restrained brace of damping performance has very big effect to the structure's dynamic elastic-plastic, and make rods force distribution is more reasonable.