###### Abstract  
The study aims to investigate the impact of uniform, grooving and non-uniform corrosion degradation on the hot-spot stresses of a T-shaped tubular joint using the finite element method. The through-thickness linearization method is employed to estimate the hot-spot stresses, allowing a more reasonable consideration of the effect of grooving corrosion and non-uniform corrosion. The grooving corrosion degradation is modelled assuming that the corrosion rate of the weld metal is 1.4 times that of the base metal. The non-uniform corrosion is modelled by moving the nodes around the weld by a random distance along the direction perpendicular to the surface. The random distances are generated based on the surface roughness parameter Ra. The results indicate that the stress concentration factor (SCF) increases with the uniform corrosion depth. The grooving corroded tubular joint results in a higher SCF than those of the corresponding uniformly corroded tubular joint. The non-uniform corrosion can lead to SCF deviations from the SCF of the uniformly corroded tubular joint. The SCF deviation at the critical region follows the normal distribution, and its standard deviation increases with Ra. fatigue; grooving corrosion; non-uniform corrosion; hot-spot stress; tubular joint 2020  
T-shaped Tubular Joint Subjected to Uniform, Grooving and Non-uniform Corrosion. 20 fatigue damage for different corrosion models. [PERSON] et al. [7] investigated the accelerated corrosion degradation of highly stressed steel, and the time-dependent SCF as a function of corrosion deterioration was analysed considering the non-uniform corrosion of welded joints. [PERSON] and [PERSON] [4] established a reliability-based model for the assessment of deteriorating ships subjected to multiple environmental conditions. The model was based on a fracture mechanics formulation, and the corrosion-induced increased crack growth rate was considered in two aspects: (1) the increased stress range produced by the plate thinning (wastage) effect and (2) corrosion fatigue itself. Following the same strategy, [PERSON] et al. [5] performed the fatigue reliability assessment of welded multi-planar tubular joints of the support structure of a fixed jacket offshore wind turbine considering the effect of corrosion and inspection. Tubular joints are widely used in offshore structures and are prone to fatigue due to the high stress concentration. The stress concentration is quantified by the SCF defined as the ratio of the hot-spot stress of a point of the weld toe to the nominal stress, which depends on the joint type, geometric dimensions, and the loading type. Extensive studies have been performed to develop parametric equations for the calculation of SCFs of tubular joints. The Efthymiou equations are widely adopted in practice and incorporated into design codes [8]. Reviews on the SCFs of tubular joints can be found in [10; 11; 12]. The coating life is not considered, and the well-developed corrosion degradation phase is dealt with in the present study. In addition to the well-known uniform corrosion, the grooving and non-uniform corrosion are investigated. The grooving corrosion is referred to as preferential weld line corrosion degradation, with a localized line of material deterioration normally adjacent to welded joints long abutting stiffeners and at stiffener or plate butts or seams [2]. Incidents probably caused by grooving corrosion in a bulk carrier were reported [13]. Some studies have been performed to evaluate the effect of grooving corrosion on the ultimate strength of stiffened plate structures [14; 15]. The effect of grooving corrosion on the load-bearing capacity of welded hollow spherical joints was investigated using the finite element method [16; 17]. The grooving corrosion may also happen around the brace-to-chord weld of tubular joints, which can affect the SCFs. However, there are no detailed studies on the modelling of the grooving corrosion in the SCF analyses and on the effect of grooving corrosion on the SCFs of tubular joints.