Gas Turbine Hot Component LCF Evaluation Based on Notch Bar Specimen

Abstract Low-cycle fatigue damage of gas turbines occurs due to rapid start and stop, rapid load changes, and operating speed fluctuations. However, in the design process, life evaluation of GT components considering the change in the transient state requires a lot of time and resources. Therefore, sufficient safety factors are applied to the material properties, or the design is made so that the low-cycle fatigue life satisfies the design life from the steady-state analysis results calculated under harsh conditions. In addition, since GT components use SX/DS and EX materials, elastic-plastic analysis is essential. In this study, a method was devised to simulate the transient process using notched bar specimens to simulate the load conditions applied to actual components. In addition, an elastic-plastic analysis method was devised using the Hill Parameter for GT materials, and sufficient design safety for the design life of GT high-temperature components was verified, and practical evaluation method for low-cycle fatigue was established.