Research On The Damping Parameters In Plastic Hinge Region

Earthquake is a very serious natural disaster that causes huge losses to human life and property. Thus the seismic performance design has a pivotal position and damping is an important parameter in seismic design.Damping properties of buildings has a very important impact to the seismic response. Study abroad in recent years show that damping performance of buildings is nonlinear. Damping ratio related to the size of structure’s deformation. In the current national seismic design of buildings, constant damping ratio model is used commonly, which does not truly reflect the nonlinear damping performance of buildings. Therefore, the problem that a reasonable value of the damping ratio is nessesary to be solved.So far, domestic and foreign scholars have studied on this issue and proposed expressions about variable damping ratio. However, none of them is proposed to describe the damping of the building when the building occurs plastic deformation.Aiming at the above problems, the main research work and achievements are as follows:(1)The relationship between the damping ratio and distortion of the building is analyzed. The value of the damping ratio has a big difference between the plastic hinge and the elastic stage of the structure.(2)This paper proposes a new about damping ratio and the deformation of shear frame structure. This expression gives different values of damping ratio when the structure is in elastic stage,or elastic-plastic stage or plastic stage.(3) This paper does secondary development using the feature of OpenSees that it is the object-oriented programming and open source. For a three-reinforced concrete frame structure, this paper analyzes the dynamic elasticoplasticity under the influence of seismic waves. In the constant damping ratio model and variable damping ratio model proposed in this paper, this paper analyzes the difference of the appearance and development of the plastic hinge, a hinge member rate, the maximum angle of the rod end and earthquake response of the structure. Constant damping ratio model can not truly reflect the seismic performance. Variable damping ratio model presented in this paper has a certain rationality.