MECHANICAL PERFORMANCE OF WELDED HOLLOW SPHERICAL JOINTS AT ELEVATED TEMPERATURES

Welded hollow spherical joints (WHSJs) have been extensively applied to spatial grid structures. However, the failure mechanism and assessment method of WHSJs under fire conditions have been rarely studied. In this study, the failure mechanism and high-temperature attenuation pattern of the axial compression performance of WHSJs at fire-induced high temperatures were explored via high-temperature axial compression experiments by using 18 specimens. A finite element (FE) model was constructed by using the ABAQUS software. The reliability of this FE model was verified by experimental results. The influencing patterns of the type of steel, stiffening rib arrangement, size of the WHSJ, and the test temperature on the high-temperature axial compression performance of WHSJs were discussed through the FE model. A simplified calculation method of the compressive bearing capacity of WHSJs at elevated temperatures was proposed on the basis of the test data and the FE parameterized analysis results. The findings of the simplified calculation method conformed to experimental and numerical simulation results. Copyright (C) 2020 by The Hong Kong Institute of Steel Construction. All rights reserved.