Research on configuration of access hole based on ultra-low cycle fatigue performance of steel beam-to-column connections
Severe cyclic loading can cause ultra-low cycle fatigue(ULCF)fracture of the materials around the access holes of steel moment connections.A general method for predicting the ULCF fracture is to substitute the stress-strain states of the material from numerical simulation into the cyclic void growth model(CVGM).The above method was extended to the improved cycle void growth model(ICVGM).The extended method was applied to the fracture prediction of connections with different access hole configurations in order to present the optimized configuration more intuitively.A calibration method for the ICVGM was proposed based on data from the literature to determine the corresponding parameters for Q355 steel.Then,the predicted results from ICVGM were compared with those of the fracture tests on local specimens of steel moment connections to demonstrate the consistency between them and verify the accuracy of ICVGM compared with CVGM.The fracture tendencies of the connections with different access holes were determined using the ICVGM to propose the optimized access hole.The FEM-based parametric analyses indicate that the fracture tendency of the joint decreases as the length of the access hole increases.The joints with the semi-circular and recommended access holes in FEMA-350 possess the lowest fracture tendencies.The optimized configuration improves the ductility of the joint by transferring the fracture point from the heat-affected zone to the base metal region.
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万方数据
维普
