Calorimetric Studies and Self-Heating Measurements for a Dual-Phase Steel Under Ultrasonic Fatigue Loading

Abstract

is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. This is an author-deposited version published in: https://sam.ensam.eu Handle ID ABSTRACTThe objective of the present research is to study the self-heating behavior of a dual-phase (DP) steel under ultrasonic fatigue loading and to investigate the effect of frequency on intrinsic heat dissipation of the material. The steel studied in this work is DP600 commercial DP steel. Fatigue tests were conducted 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 heat dissipation per cycle from temperature measurements. The variation of this dissipation versus stress amplitude in cyclic loading was also studied.

Representative volume element size determination for viscoplastic properties in polycrystalline materials

“…Further work will involve the extension of the present approach to the fatigue of metallic polycrystalline materials. The fatigue strength of polycrystalline materials is a longstanding problem in mechanical design, especially in the very high cycle fatigue regime, where the stress level is much lower than traditional fatigue limit ( Bathias and Paris, 2004 ;Stanzl-Tschegg et al, 2007 ;Phung et al, 2014 ;Torabian et al, 2016aTorabian et al, , 2016bTorabian et al, , 2017aTorabian et al, , 2017b. In order to reduce experiment duration time, many authors have resorted to the method of self-heating tests, in which the thermomechanical response of the material during cyclic loading is analyzed and the intrinsic dissipation is taken as the fatigue damage indicator to evaluate fatigue strength at various stress levels in the high and very high cycles fatigue domain ( Luong 1995 ;La Rosa et Risitano 20 0 0 ;Boulanger et al, 2004 ;Doudard et al, 2010 ;Chrysochoos et al, 2008 ;Connesson et al, 2011 ;Blanche et al, 2015 ;Guo et al, 2015 ).…”