The effects of load conditions and structural parameters on fretting wear of annular flat in heavy-duty gas turbine

Heavy-duty gas turbine is the core equipment in energy and electricity systems. In the compressor of a heavy-duty gas turbine, the forces and torques are usually transmitted by the friction force of the annular flat contact interfaces between two adjacent discs. Aimed at the annular flat connection structure of the combined rotor in heavy-duty gas turbine, the distribution of fretting characteristics on the annular flat is analyzed. The wear depth was calculated on the contact interface based on the modified Archard's wear theory and finite element method. On the annular flat, the time-varying distributions of fretting characteristics with the progress of wear are investigated. The increase of fretting cycles increases the wear depth of the annular flat. Moreover, the effects of load conditions and disc geometrical parameters on the fretting characteristics are studied. The increase of tie rod preload force and transmitted torque will intensify the fretting wear on the annular flat. In addition, the decrease of the distance between the tie rod and the annular flat and the decrease of the width of the annular flat will exacerbate the fretting wear on the annular flat. A fretting wear experiment is conducted to verify the finite element model. The experimental results show the fitting curve of wear depth decreases from the inner radius to the outer radius, which aligns with the results obtained from the finite element simulation. Ultimately, the research of this paper will provide a reference for the design and engineering application of the annular flat contact interfaces.