Research On The Shear Performance Of Prefabricated Connection

Precast structure with high construction speed,the advantages of high quality,energy saving and environmental protection,and under the advocacy in the country continues to promote green building development,policies in harmony with nature,has been widely used in various areas of buildings.The joint is the weak link of precast structure,performance of joint connection quality has an important effect on the whole and the seismic performance of the structure,the joint performance evaluation is one of the key problems of the design method of assembly structure.At present,countries used different failure mechanisms perform a calculation on shear strength of precast connection surface,but in the specifications which are in continuous improvement.This research study on shear performance of precast connection surface for objects,aim for precast structures of related specifications and provide basic data for design method.According to the research on the shear behavior of precast connection surface,complete the following tasks:First of all,the simulation results of the finite element software ABAQUS and WCOMD are used to simulate and compare with the previous experiments.Before the simulation,introduces two types of software simulation methods,respectively,adopted after the previous experimental results compared the two simulation of finite element software validation.Comparison results show that:the simulation results of ABAQUS and WCOMD can effectively reflect the cracking trend,but the trend of the load displacement curve and the skeleton curve simulated by ABAQUS is more consistent with the trend of the experimental results;the maximum carrying capacity of ABAQUS and WCOMD simulation results are close to the measured values,but the ABAQUS simulation results are better.ABAQUS simulation itself coincide with trials are generally good,therefore,to local discontinuities,ABAQUS simulation method has good adaptability.Secondly,the different parameters of the prefabricated column wall specimens were designed,and the influence of different factors on shear connection surface were analyzed.Analysis results show that:With the increase of shear strength,the shear strength of joints increases,and the ductility coefficient decreases.From HRB335 to HRB500,the shear bearing capacity increased by 23.55%,the ductility coefficient is decreased by 4.29%.With the increase of reinforcement ratio,the shear strength and ductility coefficient of the specimens increased,from 0.209%to 0.838%,the shear capacity increased by 34.88%,and the ductility coefficient increased by 33.1%.With the connection improvement of cast in place concrete strength,the shear strength of the joints increases,the ductility coefficient decreases,and when the C40 is increased to C55 the shear strength increases by 6.47%and the ductility coefficient decreases by 10.29%.With the decrease of the shear key slot width of the connecting surface,the shear strength of the joint is reduced,and the ductility coefficient increases,varies from 180mim to 90mm,the shear bearing capacity is reduced by 14.61%,the ductility coefficient increased by 18.41%.With the decrease of the shear key slot depth,connecting the shear strength decreased,the ductility coefficient increased obviously,varies from 25mm to 9mm,the shear bearing capacity is reduced by 16.84%,the ductility coefficient increased by 138.34%.The shear strength,initial stiffness and ductility coefficient of the specimens are increased with the decrease of the width of the strip,changes from 300mm to 180mm,the shear bearing capacity increased by 17.53%,the initial stiffness increased by 39.36%,the ductility coefficient increased by 19.17%.With the increase of axial compression ratio,the shear strength and initial stiffness increase,while the ductility coefficient decreases.When the axial compression ratio is changed from 0 to 0.15,the shear capacity increases by 35.55%,the initial stiffness increases by 74.84%,and the ductility factor decreases by 5.91%.Finally,through the calculation,the author compares and analyzes the domestic and international building codes and the calculation formula of shear capacity of experts and scholars.Then according to the results of simulation analysis,using regression methods,establish a precast shear connection calculation formula of bearing capacity,and the calculation results are verified.