Study On Preliminary Theory Of Self-adapting Energy Dissipation UPPC Anti-seismic Frame And Design Of Energy Dissipation Components

Prestressed concrete frame structure are widely used in the building engineering, foundation engineering, water supply and drainage engineering, hydraulic engineering, transportation engineering etc, especially in large-span multilevel prestressed concrete structure, because of its large span capacity, mechanical properties and anti-crack and anti-deformation ability, high durability, convenient construction, material saving and so on. Although many scholars at home and abroad for decades have studied a large number of seismic performance and seismic design method of prestressed structure, and also have gained great achievements in this field. However, because the number of prestressed structure designed to be applied in the seismic area are less,as also as in-depth research and experience of earthquake damage, which leads that seismic prestressed structure are needed to accumulate more experience in prestressed structure engineering. In addition, the prestressed frame structure designed by the existing specification do not easily form the beam hinge energy dissipation mechanism of strong column and weak beam owning to prestressed beam in the earthquake region that are of many reinforcement, so it is an issue and controversial hot research whether prestressed frame structure can be used in the earthquake zone. At the same time, for how to play the advantages of prestressed structure and overcome their shortcomings,as also how to adopt more advanced and effective technology to enhance and improve the seismic performance of prestressed, it is also worth of doing further research.This paper proposes a new self-adapting energy dissipation unbonded partially prestressed concrete (UPPC) anti-seismic frame structure. The main characteristics of the frame is self-adapting energy dissipation components which are reasonably arranged in the frame,and carry on the deep research on them which are used to improve the seismic performance of UPPC frame. By setting the self-adapting energy dissipation components to infrequent stress of unbonded prestressed tendons under rare earthquake, reducing the bearing capacity of the prestressed frame beam, which prompt that the UPPC frame structure are easy to realize the mechanism of the beam hinge and the lateral shif under rare earthquake. This article is to research the energy dissipation mechanism of self-adapting energy dissipation UPPC anti-seismic frame,and to do design and experiment on self-adapting energy dissipation component. Main research work and conclusions are as follows:1) Studying on the the energy dissipation mechanism of self-adapting energy dissipation UPPC anti-seismic frame,mainly on how to realize the energy dissipation mechanism of the beam hinge:the self-adapting energy dissipation components is arranged in the unbonded prestressed tendons of prestressed beam mainly through the positioning of reinforcement and stirrup reinforcement. When under the small earthquake and middle earthquake, self-adapting energy dissipation components dormant and the prestressed frame beam work normally. But under rare earthquake, when the prestressed stress is greater than the threshold, self-adapting energy dissipation components are up and get deformation according to the design requirements,which reduce the stress of prestressed reinforcement and reduce the effect of the bearing capacity of the prestressed frame beam, so that the beam hinge occurred ahead of the column hinge to realize the mechanism of beam hinge.2) Giving the basic structure and the assembling process of the self-adapting energy dissipation components. Doing the concept design of energy dissipation components,and analysis the design parameters of finite deformation box in the energy dissipation components to the impact of function and property requirements, which can propose the reference and advise of parameter optimization design of energy consuming components for various prestressed frame beam3) The finite deformation box is mainly composed of two kinds of materials which are cast iron and carbon fiber materials,through the test and Research on mechanical properties and parameters analysis of specimens which are composed of cast iron and carbon fiber materials,then on the basis of experiment, giving theoretical calculation method of the bearing capacity of the finite deformation box.4) Through the finite element software ABAQUS to establish three types of model experiments, pure iron, cast iron bottom pasted carbon fiber cloth, cast iron pasted carbon fiber plates,and the experimental models were simulated analysis of mid-span load-displacement curve. Comparing the difference between the simulation value and test value, the feasibility analysis of flexural performance of paste carbon fiber material of iron at the bottom can be preliminarily verified by the finite element software.5) Studying on the threshold of finite deformation box when it occurs damage, the arrangement of self-adapting energy dissipation components and verifying the feasibility of energy dissipation components, mainly by using SAP2000 software to do elastic-plastic dynamic analysis on one unbonded prestressed frame structure which beams are putted zigzag arrangement unbonded prestressed bar under rare earthquake. Firstly, to give the seismic performance evaluation of UPPC frame structure before not being arranged components,paving the way for the further study of the rational layout of energy dissipation components; Secondly, to determine the damage threshold of energy dissipation components under rare earthquake, mainly through the finite element analysis software giving the effect of earthquake to the unbonded prestressed steel strand stress of prestressed beam to determine the threshold; Finally, based on the structure analysis of threshold,and then combined with the analysis of parameters and mechanical properties before, the design and application effect of energy dissipation components in this structure will be given out, getting that energy dissipation components can release about 68.18% of prestressed stress.Verifying the feasibility of energy dissipation components.