| With its unique structural system and rich history and culture,Dougong has become a typical component of Chinese wood structure architecture,which is also indispensable in modern antique architecture.However,due to the limitation of its own material characteristics,there are some defects in corrosion resistance,fire resistance and durability,and it is difficult to repair.Therefore,with the continuous progress of society and science and technology,the wooden structure bucket arch in modern antique buildings is gradually replaced by concrete materials.Due to different materials,installation technology and ancient wood structure are also different,so some mechanical properties and failure patterns of the bucket arch will also change.In this paper,the low cycle cyclic loading test is carried out to study the seismic performance of the bucket arch joint,and the weak part of the bucket arch is strengthened to clarify its failure mode,which can provide guidance for the actual project.In this paper,five groups of prefabricated concrete bucket arch specimens are designed,and the experimental research is carried out under the action of low cycle reciprocating load.The parameter analysis is carried out for different axial compression ratio and different balance weight of the upper part of the bucket arch.The hysteretic curve,skeleton curve,stiffness degradation,ductility and energy consumption performance of each specimen are obtained.The failure mechanism and strain distribution of the joint area arc analyzed.The failure of the joint is mainly caused by the cracking of the concrete itself.The hysteretic curve of the specimen is full,the plastic deformation capacity of the structure at the prefabricated concrete bucket arch joint is fully exerted,and its energy consumption performance is prominent.The larger the axial compression ratio is,the more obvious the rigidity degradation of the specimen is.Through the numerical simulation,the seismic performance of the prefabricated concrete bucket arch joint is analyzed,and the results of the finite element analysis are compared with the test results.The two are basically consistent,which verifies the accuracy of the finite element model.The parameters of the bucket joint are analyzed,and the bucket with three different volume contents of steel fiber is further strengthened,and then the numerical simulation calculation of the seismic performance of the assembled concrete bucket arch joint is studied,focusing on the failure mode of the bucket and the distribution law of the stress-strain cloud diagram.The results show that steel fiber can restrain the development of plastic strain of bucket to a certain extent,which can improve the tensile strength and shear strength of bucket.Adding a certain amount of steel fiber can not only improve the seismic performance of the bucket,but also improve the overall seismic performance of the assembled concrete bucket arch. |
