Fatigue-limit prediction of standard tensile specimen using lock-in thermography

Under conductance of Lock-in thermographic method with infrared camera on a standard tensile specimen(STS), the aim of this paper is to describe the thermal stress and predict the fatigue-limit by monitoring the temperature increment of dissipations energy. By measuring temperature distributions synchronously to reference signals at periodic variation of loading conditions and from study of Lock-in Thermography monitoring defects based on both amplitude modulations of temperature differences and phase delay, linear thermo-elastic effects are evaluated and describe the dissipation energy mechanism in structures under loading condition. Also, the fatigue-limit as followings is predicted acceding to random loading conditions.