Abstract
Addressing anthropogenic climate change is a great challenge that requires integrating renewable energy resources into the grid. The intermittent nature of renewables creates a demand for more flexible gas turbine operation conditions. This increases the number of startup and shutdown cycles and leads to gas turbine components experiencing a significant increase in low cycle fatigue (LCF) loading. This study examines the LCF performance of a widely used rotor blade material to support flexible power plant operation. The study is part of a multi-year government-funded project developing a probabilistic fatigue lifetime model for cast material, including defects like cast porosity. The present work is the second contribution in an ongoing series of studies [1]. The focus of this work is the investigation of the influence of defect size and shape on LCF performance. Because defects introduce a variety of uncertainties, understanding their influence is required for developing a probabilistic approach. Additional model input parameters subject to uncertainties, such as grain sizes and orientations that significantly depend on blade location and design, are also investigated.
