Finite Element Analysis Of Tensile Behavior In Half-grouted Sleeve Connection With Defects

The half-grouted sleeve connection with defects in the prefabricated concrete structure will significantly reduce the load bearing capacity of the joint and increase the risk of premature failure of the fabricated structure.The dissertation attempts to investigate the effects of eight types of defects on the tensile behaviors of half-grouted sleeve connection under different defect levels.Firstly,we tried to analyze the forming mechanism of defects and classify their categories by site investigation of prefabricated building.To evaluate the bond behavior of half-grouted sleeve connection with defects,a total of 37 specimens with five types of insufficient grouting configuration(end,central,uniform,thickness,and horizontal),two types of rebar(depth and eccentricity),and grouting material have been simulation investigated.Secondly,the tensile behavior of the half-grouted sleeve connection under unidirectional stretching was analyzed in this paper by ANSYS Workbench finite element software.Thirdly,through the analysis of stress diagrams,load-slip curves,bond stress-slip curves and simulation results,under the different defect levels,the influences of eight types defects on the load bearing capacity,deformation performance and failure mode of half-grouted sleeve connection was revealed.The results show that,firstly,with the increase of grouting defect distribution,grouting defect thickness,rebar depth,and rebar eccentricity,the bearing capacity and deformation performance are reduced.Secondly,the half-grouted sleeve connection models failed in three modes: tensile fracture of reinforcing bars,pullout of reinforcing bars after yielding and pullout of reinforcing bars from sleeve.Thirdly,when they have same dimension,the bearing capacity and deformation performance of the model are ranked from the largest to the smallest: end grouting defect,the insufficient depth of rebar,central grouting defect,and horizontal grouting defect.Fourthly,the specimens fail in the shifting failure mode from the tensile fracture of rebar to the pulling out of rebar with the increase of defect level for all types of grouting defects,especially when the defect level excesses 30%.