Abstract
Fatigue crack initiation and propagation involve plastic strains that require some work to be done on the material. Most of this irreversible energy is dissipated as heat and consequently the material temperature increases. The heat being an indicator of the intense plastic strains occurring at the tip of a propagating fatigue crack, when combined with the Neuber’s structural volume concept, it might be used as an experimentally measurable parameter to assess the fatigue damage accumulation rate of cracked components. On the basis of a theoretical model published previously, in this work the heat energy dissipated in a volume surrounding the crack tip is estimated experimentally on the basis of the radial temperature profiles measured by means of an infrared camera. The definition of the structural volume in a fatigue sense is beyond the scope of the present paper. The experimental crack propagation tests were carried out on hot-rolled, 6-mm-thick AISI 304L stainless steel specimens subject to completely reversed axial fatigue loading.
Highlights
On the basis of a theoretical model published previously, in this work the heat energy dissipated in a volume surrounding the crack tip is estimated experimentally on the basis of the radial temperature profiles measured by means of an infrared camera
N umerical or experimental evaluation of plastic dissipation at the tip of fatigue cracks have attracted the attention of several researchers, who investigated, just as few examples, crack propagation assessment criteria [1,2], the thermal effects on stress intensity factors [3,4], the plastic zone size and energy dissipation [5,6,7]
Such experimental technique is based on temperature measurements performed by means of an infrared camera or a thermocouple glued at the point of a component where the fatigue assessment is to be performed and it has the advantage that thermal boundary conditions do not need to be controlled during experimental tests
Summary
N umerical or experimental evaluation of plastic dissipation at the tip of fatigue cracks have attracted the attention of several researchers, who investigated, just as few examples, crack propagation assessment criteria [1,2], the thermal effects on stress intensity factors [3,4], the plastic zone size and energy dissipation [5,6,7]. In a previous paper, dealing with fatigue assessment of notches, the heat energy dissipated in a unit volume of material per cycle, Q, has been assumed as a fatigue damage index and a proper experimental procedure has been put forward to estimate the Q parameter at any point of a specimen or a component undergoing fatigue loadings [8] Such experimental technique is based on temperature measurements performed by means of an infrared camera or a thermocouple glued at the point of a component where the fatigue assessment is to be performed and it has the advantage that thermal boundary conditions do not need to be controlled during experimental tests. Experimental temperature distributions have been compared with an analytical solution available in the literature
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
