Reinforcement Grouting Sleeve Under Impact Load Connection Performance Study

Reinforcement grouting sleeve connection has the advantages of rapid construction and high reliability,and has become one of the most extensive reinforcement connection methods in prefabricated structures.At present,the research results of steel bar sleeve joint mainly focus on the static uniaxial tensile and reciprocating tensile and compressive properties.At present,the research results on dynamic performance of reinforced grout sleeve connection are very rare.Therefore,it is necessary to carry out a systematic and comprehensive study to further clarify the safety performance of reinforcement grouting sleeve connection under dynamic load.This paper will carry out research in the following aspects:(1)In order to apply the impact force provided by the drop hammer testing machine to the reinforcement grouting sleeve connector,a device that can convert the impact pressure into tension is designed.Firstly,ABAQUS finite element software was used to establish the numerical model of the impact tension device to design and optimize the device.According to the optimization results,the device is processed and manufactured;The feasibility of the device is verified by the impact test of the steel bar installed in the device.(2)First,the static tensile test was carried out on the steel bar used in the test,and the bending and compressive tests were carried out on the grout material to obtain the material parameters of the specimen components.The impact tensile test of reinforcement grout sleeve connection under different loading conditions was carried out to clarify the force transfer mechanism,failure pattern and dynamic response of reinforcement grout sleeve connection,and the influence rule of parameter change was analyzed.(3)CDP model and brittle failure model are adopted for grout material,bilinear model is adopted for reinforcement and sleeve.The full-entity model of reinforcement grout sleeve connector and semi-structural model of reinforcement grout sleeve are established by ABAQUS finite element method for analysis,and systematic and comprehensive parameter analysis is carried out by numerical method.Then,the dynamic performance and parameter influence rule of reinforcement grouting sleeve connector are expounded systematically and comprehensively.The drop hammer impact test loading device is designed and the finite element analysis is compared with the test to verify the validity of the finite element analysis.A total of 17 specimens in 6 groups were tested.Combined with specimens of different anchorage lengths,the length of steel bar pulling out was obtained.