Characterization of crack tip stress fields in test specimens using mode mixity parameters

The effect of creep damage formulation on crack tip fields, creep stress intensity factor and crack growth assessments

“…In Fig.1, the results of calculations are shown for plane stress and plane strain conditions using Eqs. (8)(9)(10)(11). For constant rupture time the particular forms (8-11) of general relationships (5,6), show a marked sensitivity to stress biaxiality and material constant .…”

“…n [10] one unified parameter in the form of a plastic stress intensity factor (SIF) is introduced based on the asymptotic elastic-plastic stress and strain the crack tip fields which gives more accurate the characterization of fracture resistant properties materials and structures under static and cyclic loading than the wide spread twoparametric theories. The plastic SIF takes into account both the in-plane and out-of-plane constraint effects at fracture.…”

Effect of different environmental conditions on surface crack growth in aluminum alloys

“…The procedure for calculating of the governing parameter of the elastic-plastic stress-strain fields in the form of I n -integral for the different specimen geometries by means of the elastic-plastic FEanalysis of the near crack-tip stress-strain fields suggested by [1][2][3]. In this case, the numerical integral of the crack tip field In changes not only with the strain hardening exponent n but also with the relative crack length b/D and the relative crack depth a/D:…”

“…Third, constrain parameters behaviour and governing parameter of elasticplastic stress field distribution along the crack front was obtained using FEM analysis. Crack growth interpretation is performed using the traditional elastic and new plastic SIF [1][2][3]. It is found that there is a steady relationship between the crack growth rate and the plastic SIF in the form of general curve within a relatively narrow scatter band for all tested specimens at different temperatures.…”

A creep stress intensity factor approach to creep–fatigue crack growth

“…The approach follows that in [13][14][15][16], whereby the plastic stress intensity factor (SIF) was introduced for the different geometry of several test specimens to take into account in-plane and out-of-plane constraint effects at fracture. Equations are also proposed for calculating I n -factor at both the deepest point along the crack front and at the crack tip on the surface.…”