Experimental Research On Impact Resistance Performance Of Precast Reinforced Concrete Columns

In recent years,prefabricated reinforced concrete structures have alreadly been well developed in our country.Prefabricated structures have many advantages compared with cast-in-place structures,such as high quality,environmental protection,and rapid construction,et al.The connection reliability of the assembly position determined the performance of the prefabricated structure to a large extent.Therefore,at present,domestic and foreign research scholars have conducted a lot of researches on the connection types and connection reliability of the assembly structures.With the development of economy and transportation,accidents involving vehicles impact bridges,houses and other structures are becoming more frequent.It is worthwhile to explore the stability of fabricated structures under impact effect.Therefore,this paper conducted a pendulum impact test on four specimens which were used the currently widely used assembly column connection types,and analyzed the impact resistance performance difference of the columns with different connection types under the impact effect.At the same time,the finite element software LS-DYNA was used to perform finite element analysis on the test specimens,and the parametric analysis were also conducted,to further explore the impact resistance performance of the fabricated concrete column under different impact scenarios.The main researches in this paper are as follows:（1）A total of four reinforced concrete column structures were designed in this paper,including three prefabricated concrete columns: grouting sleeve connection column（PC1）,grouting anchor connection column（PC2）and bolt connection column（PC3）,and one for comparison cast-in-place columns（RC）.The impact tests on the four specimens had been completed.（2）The test results of impact force time history curve,displacement time history curve,steel strain time history curve and acceleration time history curve were analyzed.The energy dissipation and the propagation of the stress wave were investigated based on experimental dates.Moreover,the impact resistance performance differences of the four specimens were compared.Cracks development during the impact test process and the final failure mode were also analyzed.The test results provided experimental date support for finite element numerical simulation.（3）The RC and PC specimens were simulated by the finite element software LS-DYNA and the finite element model was calibrated.By comparing the results of the finite element simulation with the results of the test,and the overall damage development during the impact process was basically consistent with the test.（4）The finite element model of four specimens were analyzed parametrically,including axial compression ratio,impact location,velocity and mass of the impact object.The relationship between the impact dynamic response characteristic values（such as peak impact force and peak displacement）of the four specimens under different parameters was compared and analyzed,and relevant impact resistance design suggestions were given.