Abstract
This paper aims to seek expedited fatigue analysis methods using the infrared self-heating technique.The fatigue analysis of NiTi shape memory alloys is obtained through a hybrid approach:fatigue tests to failure yield relatively shorter fatigue lives,while determining the fatigue limit,normally involving extremely high cycles approaching 107 cycles,is directly achieved via self-heating tests.This methodology significantly reduces testing cycles,costing only a fraction of the several-thousand-cycle tests typically required.The validity of this approach is successfully demonstrated through fatigue testing of 18Ni steel:the entire S-N curve is examined using the traditional fatigue test until a life of up to 107 cycles,and the indicated fatigue limit agrees well with the one directly determined through the self-heating method.Subsequently,this developed approach is applied to the fatigue analysis of shape memory alloys under complex loading,enabling the concurrent estimation of the limits of phase transformation-dominated low-cycle fatigue and high-cycle fatigue in the elastic regime on a single specimen.The results obtained align well with other supporting evidence.