A model to predict the relaxation of weld residual stress by cyclic load: Experimental and finite element modeling

Experimental and analytical study of residual stresses relaxation in nitrided 42CrMo4 parts

“…The representation of the relaxed residual stresses with respect to the number of cycles N given in figure 13 shows the following points: (i) This model predicts the value of relaxed residual stress, which is close to those determined by x-ray diffraction [5,7,10,12]. (ii) The shape of the curve of the relaxation residual stress based on the logarithm of number of cycle, experimental and analytical (by applying of the Zaroog model) remains unchanged.…”

“…The modeling of cyclic relaxation of residual stresses has been studied by several researchers, many empirical equations have been proposed on the basis of experimental results. Several studies have produced estimates of residual stress relaxation phenomenon but there is still insufficient data for 42CrMo4 nitrided steel [2][3][4][12][13][14]. For this study three analytical models have been proposed in this paper in order to determine the residual stress values after cyclic loading.…”

“…Major fatigue life prediction methods modify the fatigue limits to account for the presence of residual stresses [1][2][3][4][5][6][7][8][9][10]. The compressive residual stress resulting from the different surface treatments such as shot peening, carburizing, nitriding, have a favorable effect on the resistance of fatigue crack initiation [3,7,[10][11][12].…”

“…Considerable amounts of experimental data showed that relaxation begins rapidly within the first cycles and slows with subsequent cycling. Additionally, a large relaxation of the compressive residual stress occurring on the first fatigue cycle has been observed by many researchers [1,3,4,[12][13][14][15]. Therefore, an accurate calculation of residual stresses and its relaxation becomes essential for fatigue life prediction.…”

Fatigue life prediction for butt‐welded joints considering weld‐induced residual stresses and initial damage, relaxation of residual stress, and elasto‐plastic fatigue damage

“…Consequently, there is an imminent urge to develop a method to comprehensively consider the weld‐induced residual stresses, initial damage, as well as the interactive relationship between the fatigue damage and residual stresses, when evaluating the fatigue property of welded structures. The continuum damage mechanics (CDMs) could be a suitable candidate because of its advantageous ability for describing the mechanical performance of a deteriorated material and for calculating the progressive damage by developing damage‐coupled constitutive model and thermodynamics‐based damage evolution laws . Do et al developed a nonlinear damage cumulative model, based on the CDM approach.…”