The bearing performance of the bolt-sphere joints with stochastic pitting corrosion damage

Autor: Hao Yuan, Yuejing Luo, Desheng Ai, Huijuan Liu, Xiaodan Ren, Xiuhai Zhang
Rok vydání: 2019
Předmět:
Zdroj: Journal of Constructional Steel Research. 160:359-373
ISSN: 0143-974X
DOI: 10.1016/j.jcsr.2019.05.032
Popis: The bolted spherical nodes are widely used as member joints of lattice shell structures. With long-term service in a corrosive environment, the bearing performance degradation of these nodes due to corrosion especially pitting corrosion is threatening the safety of the entire structure. The paper presents a pilot study on the bearing performance of the bolt-sphere joint portion in the bolted spherical node with stochastic pitting corrosion damage. Aided by the finite element software ABAQUS, the bolt-sphere joints are modeled in 3D incorporating the helical thread contact and progressive damage of material. The pitting corrosion is induced by explicitly adding uniform distributed pits on the intact (pit-free/uncorroded) model while the pit depth is depending on the corrosion rate and service time. With the experimental data from the uniaxial tensile bearing capacity tests on uncorroded joints and the subsequent failure mode characterization, the load-displacement responses and simulated fracture surfaces by the corresponding virtual tests on the intact model are validated. Then the virtual tests are extended to the corroded joints with different corrosion time, by which the corresponding load-displacement curves and simulated failure process are obtained. It is found that the elastic axial stiffness is degenerated by 2.6% and 4.1% and the ultimate bearing capacity is degraded by 3.1% and 5.6%, after 50 years and 100 years of corrosion, respectively. The simulated fracture surfaces indicate that the domination of shear damage is gradually weakened by the increase of pits, leading to a more ductile fracture and a flatter cup-cone fracture surface.
Databáze: OpenAIRE
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