Rapid evaluation method for compressive performance degradation of welded hollow spherical joints based on random corrosion distribution

The use of welded hollow spherical joints (WHSJs) is widespread in spatial structures. However, steel is susceptible to corrosion during operation, which can lead to a decrease in the mechanical performance of the joints and ultimately affect the overall safety of the structure. This study focuses on assessing the compressive performance degradation of WHSJs after corrosion. A sophisticated finite element model of corroded joints was developed using the life and death element method. System parameter analysis and sensitivity analysis were conducted, utilizing parameters such as the diameter-to-thickness ratio, axial corrosion ratio, circular corrosion ratio, corrosion depth, envelope ratio, and sphere diameter ratio. Considering the factors mentioned above, a grid-based method was proposed to rapidly evaluate the compressive bearing capacity degradation of corroded joints: When the corrosion area has an irregular and randomly distributed shape, this method can quickly assess the performance degradation of joints by combining "regular corrosion areas that just envelop random corrosion areas" with a "correction factor that considers the degree of random corrosion distribution". This method provides a methodological foundation and technical guidance for evaluating the safety performance of WHSJs and similar joints after corrosion.