Experimental Study On Seismic Performance Of Fabricated Bolted Joint Under Low-Cycle Reciprocating Loads

In recent years,prefabricated buildings have been vigorously promoted by the state because of the advantages of environmental protection,convenient transportation and construction,and low production cost of the factory assembly line.The prefabricated building has played a considerable role in the growing demand for residential buildings.Moreover,its applicability to innovative technologies,systematic high-quality control,low construction cycle,and low CO₂emission,has become the preferred structure of residential buildings.Its reliability,durability,and stability have a very important impact on the safety of the whole structure.The seismic analysis of beam-column joints is the core problem of the whole structure.In order to study the aseismic behavior of prefabricated dry beam-column joint under cyclic load,a novel type of dry beam-column joint is proposed,which consists of exposed corbel column,T-beam,and connected by 8 standard bolts.The joint is subjected to vertical periodic vibration load.The failure mode,hysteretic behavior,stiffness degradation,and ductility of the joint were investigated by comparing the test with the finite element model.On this basis,further optimization of 12 standard bolted joints is proposed for research and analysis.The main work and conclusions are as follows:（1）The research of prefabricated building structures at home and abroad is classified and summarized.The key to affecting the seismic behavior of the structure is the conduction and energy consumption behavior of each joint.The strength,deformation,energy consumption,and connection position of the joint are the key points of the research.This paper analyzes the development of prefabricated building structures in China and puts forward the research content of a novel type of concrete beam-column joint connected by bolts.（2）In this paper,a novel type of dry joint connected by 8 grade 5.6 standard bolts is proposed,and the design structure of the new type dry-type joint,the fabrication and assembly of test components,the test device,and the test scheme are introduced.（3）The core area bolts that connected by 8 grade 5.6 standard bolts are damaged,steel plates are deformed,and cracks appear at the T-beam end,but the overall structure is stable without significant deformation failure.The reliability of the finite element model analysis is proved by comparing the test and the three-dimensional finite element model.Moreover,connected by 12 grade 5.6 standard bolts are further proposed for the research and analysis.（4）The finite element software ABAQUS carries out the finite element numerical simulation analysis of connected by 8 grade 5.6 standard bolts,connected by 12 grade5.6 standard bolts,and traditional cast-in-place joints.The main material parameters,initial conditions,and boundary conditions of the finite element model are consistent with the experimental results.By comparing and analyzing the calculation results of three-dimensional finite element models of the 3 nodes,it is concluded that the seismic capability of the novel type dry joints is better,which meets the requirements of seismic codes.The results show that the anti-seismic capacity of the novel type dry joint is equivalent to that of the traditional cast-in-place joint.Although the bolt damage and deformation in the core area of the joint,the performance of the steel plate is damaged,and the end of the T-beam is cracked,the overall structure remains stable without large deformation and failure.Further research shows that the bolt has a significant energy conservation effect,reducing the damage and deformation of the joint core area.The seismic performance of a joint connected by 12 standard bolts is better than that of a joint connected by 8 standard bolts,and the new dry joints conform to the seismic design concept of"strong joints and weak members".Figure[46]table[6]reference[76]...