Heat dissipation energy under fatigue based on infrared data processing

Abstract

The presented work is devoted to the experimental study of heat dissipation process caused by fatigue crack propagation. To investigate a spatial and time temperature evolution at the crack tip, set of experiments has been carried out using plate titanium specimens with pre-grown centred fatigue crack. An original mathematical algorithm for experimental data treatment has been developed to obtain the power of heat dissipation caused by plastic deformation at the crack tip. The algorithm includes spatial-time filtration and relative motion compensation procedures. The time dependence of the stored energy was calculated as the difference between work caused by plastic deformation near the crack tip and heat dissipation energy obtained from experimental data. As a result, it has been shown that the stored energy has to accumulated during the fatigue test and has to be equal to zero when the crack reaches the critical length corresponding to the failure of sample.