Studies On Aseismic Performance Of Novel Energy Dissipation Toggle-Braced Systems

The steel structure has less damping ratio than the concrete structure, it only can dissipate the viberation energy by plastic deformation after quite big side shifter. The effect way to improve the antiknock ability of the structure is to increase the damping ratio by building in additional energy-dissipation devices in the structure. The study and appliance of this aspact is at large that the damper can exert the function only in the case of mega-deformation.In toggle-brace systems, the damper was fixed near the toggle. The deformation of the energy-dissipation device is much larger than the structural drift, the damper can exert the function even in small structure deformation. The study on toggle-brace system in existence is to solve the question of energy-dissipation about the rigid building, mainly fixxing linear viscous damper, increasing the damping, with litt.e side stiffness increment. The study of this paper put the emphasis on displacement-correlation damper, increase the stiffness while increasing the damping, achieving a obvious effect on energy dissipation and shock absorpation of the structure.This paper firstly compares the several existing energy-dissipation brace system, advancing a non-bonding reverse toggle upper e:iergy-dissipation device and double X mild steel damper. In succession, according to the situation of little deformation and mega-deformation, analysed the complex nonlinear relationship between relative displacement of the damper and the drift of steel frame in particular, the force of the linear damper is magnified in the coefficient of the structural drift.Then, by adding mild steel damper and friction damper, this paper analysises the relationship between the damping character and he coefficient and the parameter, the results showing that the brace configuration with a bigger displacement magnification factor is so good to increase the additional damping of the structure.And then, this paper concluded that the toggle-brace can match the different performance requirements of the steel structure designed for earthquake, by using a nonlinear time history analysis of a steel frame with chevron and different brace systems.Because the toggle-brace magnifies the displacement in a new mechanism, this paper analysises the effection of the parameters of additional displacement-correlation damper in later so much numerical calculation, showing that the coefficient of the displacement-magnified has a notable effect on the structure's displacement and the base shear The second stiffness coefficient of the damper is evident to the structure displacement but not to the base shear. The toggle-brace system can also act in small elastic amplitude when the coefficient is rather bigger; The base shear of the toggle-brace system reduced in a even wide range of yield displacement and initial rigid when the coefficient is constant.Finally, based on the results of nonlinear time history analysis, working out a analytic procedure to calculate the damping ratio by using the FORTRAN 95 language, discussing the definition of "time history damping ratio" of the steel frame with toggle-brace energy dissipation system.