High-temperature LCF behaviour of Gaussian-pitted high-strength high-ductility steel rebars.

• LCF tests on high-strength rebars assess effects of pitting corrosion and high temperatures. • Modeled Gaussian pit morphology leads to analytical stress concentration model. • Identifies fractography augmented factors contributing to faster fatigue failure in corroded rebars. • Corroded rebar softens faster under fatigue, requiring fewer cycles to reach the same level. • Corroded rebars lose upto 91 % of their energy dissipation capacity from 400 to 700 °C. Fatigue of high-strength high-ductility steel rebars under pitting corrosion and high-temperature remains largely unknown, specifically concerning temperature-dependent pit sensitivity effects, limiting their widespread adoption despite advantages. This study performs high-temperature, low-cycle fatigue tests on Fe 500D rebars with Gaussian pits. Moreover, experimental results are compared with average strain energy density method, augmented with fractography-based, temperature-dependent parameter models, including exponential pit sensitivity function. Results show accelerated cyclic softening, with up to 94% and 91% reductions in fatigue life and energy dissipation capacity in corroded rebars, respectively. The findings enhance fatigue life predictions, aiding the design of more resilient and safer structures. [ABSTRACT FROM AUTHOR]