Abstract：To address the creep-fatigue interaction failure of combustor liners in aero-engines subjected to complex thermo-mechanically coupled loads during high-temperature service, a life assessment methodology for combustor liners under elevated temperatures is developed. Based on a thermo-mechanically coupled cyclic viscoelastic–plastic constitutive model, a creep-fatigue interaction damage model is further introduced. Together, these models provide a unified description of the mechanical response and damage evolution of the material throughout the entire heating-holding-cooling cycle. GH5188 superalloy is selected as the target material. A series of experiments is conducted, including high-temperature tensile tests, low-cycle fatigue tests, and high-temperature creep tests. These experiments are used to identify the material parameters required for the proposed model, as well as to investigate the deformation behavior and creep characteristics of the alloy under cyclic thermo-mechanical loading. The experimental results indicate that the ratcheting effect of the alloy is negligible under the loading conditions considered in this study. Based on the calibrated material parameters, thermo-mechanically coupled finite element simulations of the combustor liner are performed using a commercial software platform. The simulations are employed to analyze the stress-strain response, damage distribution, and life evolution in critical regions of the liner, particularly near mixing holes where stress concentration occurs. The numerical results reveal that, with increasing loading cycles, the damage evolution of the combustor liner gradually transitions from fatigue-dominated to creep-dominated behavior. The proposed methodology provides a more comprehensive description of the coupled mechanical response and damage evolution of combustor liners under high-temperature service conditions. It offers an effective theoretical framework and analytical tool for life prediction and engineering design of high-temperature structural components, with strong potential for practical application in aero-engine structural integrity assessment.
2026, Vol. 47 
