Self-Heating Measurements for a Dual-Phase Steel under Ultrasonic Fatigue Loading for stress amplitudes below the conventional fatigue limit

Abstract

The aim of the present research was to study the self-heating behavior of a dual-phase steel under ultrasonic fatigue loading for stress amplitudes lower than the conventional fatigue limit. The steel studied in this research was DP600 commercial dual phase steel. Fatigue tests were conducted for different values of stress amplitudes up to 107 cycles using an ultrasonic fatigue machine at a testing frequency of 20 kHz with flat specimens. An infrared camera was used to measure the mean temperature evolution during the tests. A specific form of heat diffusion equation was adopted in this work to calculate the intrinsic dissipation from temperature measurements. The variation of the dissipated energy versus stress amplitude under cyclic loading was also studied.