SEISMIC Analysis of high-rise buildings with composite metal damper

This paper mainly studies on the mechanical characteristics and application effect of composite metal damper in the high-rise buildings via the numerical simulation analysis. The research adopts the elastic and elastic-plastic dynamic approach and the displacement time history response and damper energy dissipation capacity and so on of the high-rise building are compared and analyzed before and after installation. The analysis found that the energy dissipation characteristic of metallic dampers is good. High-rise building story drift significantly is reduced and the extent of damage of the walls and coupling beams is decreased, achieved a good energy dissipation effect. Composite metal damper can effectively and economically improve the seismic performance of high-rise buildings, meet the requirement of the 3-level design for seismic resistance. The result has certain reference significance for the application of metallic damper in the high-rise buildings.


INTRODUCTION
Recently, energy dissipation technology is widely used in engineering.This technology breaks through the limitation of traditional seismic design method, it can effectively improve the structural seismic performance, reduce the seismic response [1] .
According to the mechanism of energy dissipation, the commonly used energy dissipation devices are divided into two types: displacement correlation damper, the velocity dependent damper [2] .The velocity dependent damper includes viscous damper and viscoelastic damper; The Displacement correlation damper comprises friction damper and Metal damper [3] .
And the metal damper contains mainly composite metal damper and hysteretic damper.The damping effect is poor under small earthquakes.However, the composite metal damper with superior performance of energy consumption, simple structure, convenient manufacture, low cost, easy replacement [4] , is recognized by scholars, engineers and technicians gradually.
Nowadays, high-rise buildings have more motives.
The use of shear wall structures accounted for 90% of high-rise residential [5] .Demand for earthquake energy dissipation for high-rise shear is booming.Many scholars have studied the methods to improve the aseismic behavior of shear wall structure.The existing research mainly concentrated in the joints and energy dissipation device and other aspects, such as shear wall with slits [6] , combination filling of energy dissipation shear wall [7] and shear wall with vacillated rocking energy swing [8] .Compared to the general shear wall structure, those buildings have obvious optimization performance.These methods have some rationality, but the construction to apply them is not convenient.

ENGINEERING APPLICATION
Composite metal damper used bilinear model in the  The damper yield force: 30t Damper rated travel: 4cm The maximum stroke damper: 5cm The natural period of vibration is an important basis for judgment of rationality of the structure design of high-rise building.Base shear is a macroeconomic indicator to reflect the total seismic force of structure during an earthquake.
From Figure 10 we can see that, The average bottom shear of structures without damper in x direction is 30998kN, is 34252kN with damper, reduced by 6.7%.
The average bottom shear of structures without damper in y direction is 42145kN, is 34252kN with damper, reduced by 18.7%. 11002-p.4

MATEC
Web of Conferences calculation as shown in Figure 1.Bilinear model includes three parameters: second elastic stiffness, stiffness and yield strength.

1 kFigure 1 .
Figure 1.Bilinear hysteretic model of composite metal damper The project in this paper is a concrete project with damping technology in high rise building.The system of it is frame shear wall, 2 layer underground, 31 floors on the ground, the total height 97.65m.The seismic intensity is 8 degrees, 0.20g design basic acceleration, seismic design group is the first group, the construction site is three categories, the characteristic period of design earthquake response spectrum is 0.42 seconds, Frame and Shear wall seismic grade both Rank as class 1, the basic wind pressure is 0.45kN/m 2 .For this purpose, use concrete wall as the upper damper support, this can not only increase the support stiffness, but also preserve effect of heat preservation and heat insulation, sound insulation of wall.Damper model was preliminarily selected, after considering the structure characteristics and the construction pattern layout, with optimized design, 100 dampers are arranged, with two each layer along 2~26 layer Along the X direction and y direction.The dynamic parameters, Location, Quantity are determined through calculations repeatedly.The basic parameters are shown as follows.The first stiffness: 1E6 kN/m The Second stiffness: 0 kN/m

Figure 2 .Figure 3 .Figure 4 .Figure 5 .Figure 6 . 3 MATECFigure 7 . 8 )Figure 8 .
Figure 2. Perspective structure model According to requirements of "code for seismic design of buildings", during time history analysis, the paper adopts three Seismic waves as follows: site LWD_90 wave, namjyeong-2 wave and one based on artificial wave packet generated seismic site classification.They are shown in fig. 3 to 5 below.

Figure 9 .Figure 10 . 1 . 2 .
Figure 9. Average inter story displacement angle of structure under the three wave of X, Y direction

Table 1 .
Contrast of the first 3 order periodic (unit: s) Through Comparative test quality, cycle, modal, as table 1~3 show, the finite element shows that the established model is reasonable and accurate.

Table 2 .
The total mass of structure comparison (unit: t)

Table 3 .
Comparison of base shear of structures under