Earthquake Resistance Analysis Of Unbonded Prestressed Concrete Frame Joints

The use of assembly architecture is the only way to achieve industrial construction.The traditional assembly of concrete frame joints in the node connection is not reliable,not easy to meet the cyclic load under the impact of seismic requirements,and on-site assembly process cumbersome,not suitable for a large number of promotion.Prestressed preloading is applied to the prefabricated assembly nodes,and the prestressed connection of the prestressed tendons in the joint area can effectively increase the integrity and continuity of the nodes against the repeated loads,thus achieving the reliability of the assembly of the frame The corresponding seismic requirements,is conducive to prefabricated structure in the earthquake area can be a better promotion and application.The prestressed assembly structure perfectly combines prestressing technology with assembly technologycombining the advantages of both,as a means of achieving this goal.At present,mainly through the test to study the prestressed assembly structure,reliable finite element simulation means to be further explored.In this paper,ABAQUS software is used to analyze the finite element simulation under the low-cycle repeated loading in the pre-stressed assembly frame.The push-over analysis of the prestressed assembly-only frame is carried out by using SAP2000 software and ABAQUS software respectively.The main contents of this paper and the conclusions are as follows:1.combined with unbonded prestressed assembly frame in the low-cycle reciprocating load of the test,including a cast-in-place node,three prestressed assembly frame in the node,the use of ABAQUS general finite element calculation software to establish the corresponding framework node.The YPCJ-1,YPCJ-2 and YPCJ-3 models are used to analyze the ABAQUS preprocessing process in each model.The YMCJ-1,YPCJ-2 and YPCJ-3 models are used in the pre-stressed assembly frame.According to the technical specification JGJ1-2014 of the assembled concrete structure,the YHMCJ in the post-pouring integral frame is established and the finite element simulation analysis is carried out.The finite element analysis of the prefabricated structure is also carried out reliability.2.The finite element simulation analysis of the prefabricated frame is carried out.The results of the analysis of the test results and the analysis of the seismic performance of the joints are carried out in this paper.The results are shown in Fig.1 for the simulation of the failure modes,energy dissipation capacity,hysteresis curve,skeleton curve,ductility coefficient and so on.Meta-analysis results.The results show that the main seismic performance of ABAQUS simulation results is in good agreement with the experimental results,which proves that the finite element simulation method has good reliability and validity,and can be based on the data of finite experiment combined with scientific numerical analysis,Further study the seismic performance of prestressed assembly structures.3.The shear stress mechanism of the prestressed assembly frame is analyzed by using the numerical simulation results.It is found that the improvement of the shear capacity of the prestressed assembly node is mainly due to the pressing effect of the prestressing force.The shear strength calculation formula of the prestressed concrete joint is put forward.The finite element simulation analysis of the prestressed strength is carried out.The contribution coefficient of the shear strength of the prestressing extrusion is deduced,For the actual value of the project to provide a reference.4.According to the above analysis,the YPCJ-2 model with eccentricity of 95 mm is selected to change the relevant parameters.The finite element simulation analysis is carried out to study the influencing factors of prestressed concrete joints.The main influencing factors include node assembly,according to the above finite element analysis results,the main factors influencing the influence of the factors on the joint skeleton curve,the limit of the stress,the strength of the concrete,the strength of the reinforced concrete,the influence degree of each influencing factor on the ultimate load is analyzed,some suggestions are given for the future analysis and structural design of the prestressed assembly frame.5.Combined with the prestressed concrete single-frame test,the SAP2000 software was used to establish the corresponding one-span three-layer single-cast concrete frame and prestressed concrete frame finite element model.Using ABAQUS to establish the corresponding prestressed Frame model,the SAP2000 and ABAQUS finite element analysis software were used to analyze the static and elastic Pushover analysis of the single-pile frame.The position and sequence diagram of the plasticity were obtained during the pushover analysis.The results were compared with the experimental results.Stress-based single-frame failure mechanism,and the use of SAP2000 software through the optimization of the parameters of the pre-stressed assembly frame is more conducive to post-earthquake repair beam hinge failure mechanism,The studies shoved that the pre-stressed assembly frame and cast-in-place concrete single-pin Framework of the destruction of the same mechanism,in line with the norms of "strong column weak beam design." For the prestressed fabricated frame structure,the beam hinge failure mechanism can be realized by increasing the column stiffness.