Abstract: In this paper, a new type of precast concrete frame joints with wrapped steel tube and tie-bar was designed and constructed, and low cyclic loading tests were conducted. A total of four full-scale joints were designed for the tests, and the effects of the thickness of the wrapped steel tube and the reinforcement plate in the core area of the joints on the joint bearing capacity and stiffness were studied. Based on the existing experimental research results, the ABAQUS finite element model was established to simulate the mechanical properties and damage modes of the joints under cyclic loading, and to analyze the force mechanism of the joints. In the model, a plastic damage constitutive model of concrete, a bilinear elastoplastic model of steel reinforcement, and a mixed strengthening constitutive model of steel structure were adopted with the definition of steel flexible damage. The comparative test results show that the model accurately simulates the degradation of joint bearing capacity and the pinching of hysteresis curve, verifying the applicability of the model damage criterion. The energy consumption and stiffness degradation of the model were analyzed, and the effects of parameters such as the diameter of the tie-bar, the extension height of the wrapped steel tube, and the axial compression ratio on the mechanical properties of the joints were further investigated.
Keywords: precast concrete frame joints; tie-bar; finite element analysis; damage criterion
合肥工业大学学报自科版