Effects of Loading Rate on Creep Crack Growth During the Succeeding Load-Hold Period Under Trapezoidal Fatigue Waveshapes

摘要

When turbines are started up in power plants, the procedures recommended by the manufacturer should be carefully followed. However, many utilities often start turbines so fast that they accelerate the crack growth of existing cracks. Hence, in order to accurately predict the crack growth life of a turbine rotor, a crack growth prediction model is needed in which the effects of load increase time on the creack growth rate during the succeeding load hold period are considered.