Research On Damping Performance And Application Of The Constrained U-shape Soft Steel Damper

Structural vibration control is through the installation of energy dissipation devices or non-load-bearing energy dissipation members on the structure,at present,structural vibration control technology has been widely used in tall buildings and bridges,the method of setting soft steel dampers to dissipate seismic energy in the structure began with the research of Kelly et al,the U-shaped soft steel damper is one of the most typical representative of the soft steel damper and widely used in engineering practice;at the same time,the rationality of the optimal allocation of U-shaped soft steel dampers in engineering structures is an important link in the design of vibration absorption structures,the problem to be solved is how to allocate the energy dissipation device which can not only make the control effect reach the target effect but also economize.How to design the U-shaped soft steel damper which is more suitable to the practical needs and how to determine the reasonable allocation of the damper is an important subject.This paper revolves around this subject,we design and analyze the constrained U-shaped soft steel dampers,the optimal allocation of U-shaped soft steel dampers in high-rise concrete frame structure and its vibration absorption effect are analyzed and studied.The main work and conclusions of the Institute are as follows:1.The modal analysis and dynamic nonlinear analysis of concrete frame structure are carried out by three different seismic waves,from the results of the analysis of the data,we can get:the stress of the whole structure is reasonable;under the action of 7 degree earthquake(acceleration peak 35gal),elastic interlayer displacement angle of concrete frame structure conforms to the requirement of Code for Seismic Design of buildings GB50011-2010,less than 1/550;under the action of a rare earthquake of 7 degrees(peak acceleration 220gal),high-rise concrete frame structures have entered an elastic-plastic working state,if the structure is in elastic working state under rare earthquake,this high-rise concrete frame structure has the need of earthquake absorption.2.A U-shaped soft steel damper with constrained position is designed and its advantages are described.Using it as a unit,a U-shaped soft steel energy dissipation device which can be used in energy dissipation support is proposed.Then the finite element model of the damper is established,by analyzing the numerical results of the dampers,the results are obtained:with the increase of the amplitude of displacement load,the maximum restoring force of dampers increases slowly and exponentially,and provides a brief design step in engineering practice;a formula for calculating the maximum restoring force of the damper is proposed by using the fitting method,and the relative error is analyzed,the results show that the formula fits well.3.The vibration absorption system of U-shaped soft steel damper is added to the large high-rise concrete frame structure,Through analysis,it is known that without U-shaped soft steel dampers under the condition of vibration absorption system,the maximum value of axial force of beam and shear force of column is about 400KN.therefore,in order to further exert the damping effect of U-shaped soft steel dampers,the tonnage of the dampers is initially determined to be 600kN.4.the interlayer displacement iteration method,the optimal quadratic performance index loss method and the general allocation method are used to allocate the position of U-shaped soft steel dampers.By comparing and analyzing the effect of vibration absorption,it is found that the interlayer displacement iterative method with U-shaped soft steel dampers has the best effect on the vibration absorption of the structure.And based on the limit target of elastic interlayer displacement angle,Based on the allocation of U-shaped soft steel dampers by means of the interlayer displacement iteration method,the vibration absorption system of high-rise concrete frame structures with U-shaped soft steel dampers is finally optimized,according to the analysis,all the indexes of earthquake absorption are relatively optimal.5.It is determined that the mechanical formula of dampers obtained in the second chapter of this paper can be used in the design of vibration absorption of high-rise concrete frame structures.The main innovations of this paper are as follows:1.An energy dissipation device of U-shaped soft steel damper is designed,which can be used in the form of energy dissipation braces to reduce the vibration of building structures.2.A mathematical formula for the relationship between the maximum restoring force of the damper and the amplitude of the displacement load is presented.A maximum restoring force model is proposed which consider the influence of the structural size of U-shaped steel plate on the constrained U-shaped soft steel dampers.