Numerical analysis of dynamic characteristics and fatigue life of worn chain rings in scraper conveyors

Scraper conveyors operate in harsh environments, leading to wear and breakage of the chain rings. To analyze the dynamic characteristics and fatigue failure of chain rings under realistic wear conditions, this study utilizes 3D scanning to create worn chain ring models, which are incorporated into the scraper conveyor rigid-discrete coupling model for simulation. The dynamic characteristics, including chain tension, displacement, and contact forces among the coal particles, sprockets, and chain, are investigated through coupled simulation. The stress distribution and fatigue life of both normal and worn chain rings are analyzed using the finite element method, and fatigue crack propagation is investigated using ABAQUS and FRANC3D. The results indicate that the contact force, maximum equivalent stress, and strain are lower when the worn chain ring engages with the sprocket compared to the normal chain ring. Additionally, the displacement in the Z -direction increases by approximately 11 mm during chain return. The fatigue life decreases significantly, with the normal chain ring experiencing 3462 load cycles, while the worn chain ring undergoes only 68.44 cycles. Crack analysis reveals a non-linear relationship between crack depth expansion and load cycles, with the crack expansion rate increasing fourfold.