Study On The Joints Of Composite Beam And Continuous Compound Spiral Hoop Reinforced Concrete Column

With the improvement of science and technology, the composite structure constituted by steel beam and concrete column has been applied more and more in Japan because of low cost and good performance, the structure system constituted by composite beam (SC beam) and continuous compound spiral hoop reinforced concrete column (CCSHRC column) has more superiority than the structure constituted by steel beam and concrete column. In the SC beam and CCSHRC column structure system the structural dead-weight is depressed, the clean use area increases and less materials are used, this system also posses the advantages of the normal concrete structure and steel structure. Especially in the time that the civil structural steel product yield increases by degrees year after year, the bringing forward of this system accords construct ministry's appealing of construction industrialization and developing the structural steel products using. The endplate bolted SC beam and CCSHRC column joint and the bar passing force's joint of SC beam and CCSHRC column are the same with SC beam and CCSHRC column structure system, the bar passing force's joint of SC beam and CCSHRC column is audacious innovation of joint types. The joints' failure mechanism, the bearing capacity of core zone, hysteretic behavior under horizontal load and influence of the ratio of reinforcement in SC beam on the joint's behavior are not clear, and making these clear is very important in guiding design, popularizing the SC beam and CCSHRC column structure system and correlative code. At this point, the paper mainly does work as follows:For the first time the quasi-static tests are done to the full size endplate bolted connection of the SC beam and CCSHRC column specimen, the full size bar passing force's joint of SC beam and CCSHRC column specimens and the corresponding simulating core zone specimens to study the joint's seismic behavior and strength, the configuration advise is brought forward according to the test phenomenon and the test results.For the first time the three dimension finite element model of the full size endplate bolted connection specimen and simulating core zone specimen are set up by the solid element, the contact problem of the endplate and column surface and the material nonlinear of concrete, steel and bar are taken into account in modeling at the same time, the stress distributing in joint zone is accurately analyzed by the rational element meshing, also the seismic behavior of the joint under cyclic load is studied, the test results and finite element results are contrasted. Finally theauthor analyzes the concrete strength, the ratio of reinforcement in the SC beam and steel strength's influences on the joints seismic behavior.For the first time the endplate bolted connection's finite element model with the original crack is set up by the singular element, the fracture problem study is introduced to the finite element analyzing. The J integral value and stress intensity factor of the crack tip are calculated by the ANSYS Parametric Design Language program, and the developing of original crack is judged from the K Rule and J Integral Rule. Finally author analyzes the width of the original crack, concrete strength and the ratio of reinforcement in SC beam's influences on the fracture parameters such as the J integral value and crack mouth open displacement.The core zone bearing capacity formulas of two types of joints based on the tests are brought forward respectively according to the tests. For the endplate bolted connection of SC beam and CCSHRC column, the core zone bearing capacity formula based on the finite element analyzing is also brought forward, at the same time the test values of core zone's bearing capacity, the formula calculating values based on test and based on finite element analyzing are compared.The results of test and finite element analysis can guide the design of endplate bolted connection of SC beam and CCSHRC column, simultaneously the paper is use for reference in structural fracture analysis.