Compressive strength of corroded special-shaped welded hollow spherical joints based on numerical simulation

Abstract

Special-shaped welded hollow spherical joints (WHSJ) are increasingly used in several important spatial grid structures. The corrosion of WHSJ is inevitable and can eventually threaten structural safety. There is no research or comparison on the compressive strength of corroded special-shaped WHSJ. Therefore, through the simulation and analysis of the corrosion depth, corrosion mode, corrosion size, joint size, and steel material, the compressive strength of three types of special-shaped WHSJ after corrosion was studied, and the corresponding evaluation method for compressive strength was established. Results indicated that the loss of wall thickness (Tc/T) and the ratio of grooving corrosion (2Wc/D) were the key factors affecting the compressive strength of the special-shaped WHSJ after corrosion. The effect of corrosion on the bearing capacity was related to the size ratio (d/D). WHSJ connected by the H-beam were most affected by corrosion; the failure mode was basically buckling failure, but punching failure might occur in the H-beam WHSJ. The results obtained could form the basis for the selection of the WHSJ shapes and the evaluation of the bearing capacity of the space grid structure with special-shaped WHSJ after corrosion.