Abstract
In this study, several two-parameter- concepts are analyzed experimentally and numerically with respect to their capability of characterizing in-plane and out-of-plane crack tip constraint effects. Different approaches utilizing the second term T stress of the linear-elastic crack tip stress field, a higher term A 2 of the power-law hardening crack tip stress field, a hydrostatic correction term Q for a reference stress field or the local triaxiality parameter h are compared. Experimental results for a pressure vessel steel 22NiMoCr3-7 are investigated by means of the different approaches regarding their capability of constraint characterization for enhanced transferability. Theoretical aspects are investigated in a modified boundary layer analysis and in three-dimensional nonlinear elastic-plastic finite element analyses of the specimens. It is found that, with respect to their capability of quantifying combined in-plane and out-of-plane constraint effects, the investigated concepts differ significantly.
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Abbreviations
- a :
-
Crack depth
- A i :
-
Intensities of the first three terms of the power-law hardening crack tip stress field
- B :
-
Specimen thickness or crack front length
- E :
-
Young’s modulus
- \(f^{(k)}_{ij}\) :
-
Circumferential stress distribution of the linear-elastic crack tip stress field
- h :
-
Stress triaxiality parameter
- I :
-
Constant of the HRR-singularity
- J :
-
J-integral
- J c :
-
Fracture toughness
- J elastic :
-
Elastic part of the global J-integral
- J 2 :
-
Second invariant of the Cauchy stress tensor
- K :
-
Stress intensity factor
- K I :
-
Mode-I stress intensity factor
- K Ic :
-
Fracture toughness
- K J :
-
Stress intensity factor determined from J-integral
- \(\dot{K}\) :
-
Loading rate
- K Jc :
-
Fracture toughness
- l :
-
Reference length scale parameter
- n :
-
Hardening exponent in the Ramberg–Osgood constitutive equation
- Q :
-
Q-parameter, additional hydrostatic stress superimposed on a reference field
- Q BLA :
-
Q-parameter determined from a FE small scale yielding reference field
- Q HRR :
-
Q-parameter determined from the HRR-singularity as reference field
- Q t :
-
Q-parameter determined from the out-of-plane stress component
- r :
-
Radius of crack front polar reference system
- s i :
-
Exponents in the power-series expansion of the power-law hardening crack tip stress field
- T :
-
Actual testing temperature
- T 0 :
-
Master curve reference temperature
- T stress :
-
Intensity of the second term of the linear-elastic crack tip stress field
- w :
-
Specimen nominal width
- x i :
-
Cartesian coordinates
- z :
-
Thickness coordinate of crack front polar reference system
- α :
-
Parameter in the Ramberg–Osgood constitutive equation
- δ ij :
-
Components of the unit tensor
- ε ij :
-
Components of the linearized strain tensor
- ε 0 :
-
Strain parameter in the Ramberg–Osgood constitutive equation
- η :
-
Plastic correction factor
- ν :
-
Poisson’s ratio
- φ :
-
Angle of crack front polar reference system
- σ ij :
-
Components of the Cauchy stress tensor
- σ′ ij :
-
Deviatoric components of the Cauchy stress tensor
- \(\tilde{\sigma}^{(k)}_{ij}\) :
-
Circumferential stress distribution of the power-law hardening crack tip stress field
- \({\sigma^{\rm ref}_{ij}}\) :
-
Reference crack front stress field
- σ e :
-
v. Mises equivalent stress
- σ I :
-
Maximum principal Cauchy stress
- σ 0 :
-
Yield stress
References
ASTM Standard E1921-02 (2002) Standard test method for determination of reference temperature T 0 for ferritic steels in the transition range. American Society for Testing and Materials, West Conshohocken, PA
Brocks W and Schmitt W (1995). The second parameter in J–R curves: constraint or triaxiality?. In: Kirk, M and Bakker, A (eds) Constraint effects in fracture—theory and applications, vol 2, ASTM STP 1244, pp 209–231. American Society for Testing and Materials, West Conshohocken, PA,
Chao YJ, Yang S and Sutton MA (1994). On the fracture of solids characterized by one or two parameters: theory and practice. J Mech Phys Solids 42: 629–647
Chao YJ, Zhu XK, Kim Y, Lar PS, Pechersky MJ and Morgan MJ (2004). Characterization of crack-tip field and constraint for bending specimens under large-scale yielding. Int J Fract 127: 283–302
Du ZZ and Hancock JW (1991). The effect of non-singular stresses on crack-tip constraint. J Mech Phys Solids 39: 555–567
Henry BS and Luxmoore AR (1997). The stress triaxiality constraint and the Q-value as ductile fracture parameter. Eng Fract Mech 57: 375–390
Hohe J, Tanguy B, Friedmann V, Stöckl H, Böhme W, Varfolomeyeva V, Hebel J, Burdack M, Fehrenbach C, Schüler J, Sguaizer Y, Siegele D (2004) Kritische Überprüfung des Mastercurve-Ansatzes im Hinblick auf die Anwendung bei deutschen Kernkraftwerken, Report No. S8/2004. Fraunhofer Institut für Werkstoffmechanik, Freiburg
Hohe J, Hebel J, Friedmann V and Siegele D (2007). Probabilistic failure assessment of ferritic steels using the master curve approach including constraint effects. Eng Fract Mech 74: 1274–1292
Hutchinson JW (1968). Singular behavior at the end of a tensile crack in a hardening material. J Mech Phys Solids 16: 13–31
Kfouri AP (1986). Some evaluation of the elastic T-term using Eshelbys method. Int J Fract 30: 301–315
Kim Y, Zhu XK and Chao YJ (2001). Quantification of constraint on elastic-plastic 3D crack front by the J–A 2 three-term solution. Eng Fract Mech 68: 895–914
Kim Y, Chao YJ and Zhu XK (2003). Effect of specimen size and crack depth on 3D crack-front constraint for SENB specimens. Int J Solids Struct 40: 6267–6284
Nakamura T and Parks DM (1992). Determination of elastic T-stress along three-dimensional crack fronts using an interaction integral. Int J Solids Struct 29: 1596–1611
Nikishkov GP (1995). An algorithm and a computer program for the three-term asymptotic expansion of elastic-plastic crack tip stress and displacement fields. Eng Fract Mech 50: 65–83
O’Dowd NP (1995). Applications of two parameter approaches in elastic-plastic fracture mechanics. Eng Fract Mech 52: 445–465
O’Dowd NP and Shih CF (1991). Family of crack-tip fields characterized by a triaxiality parameter—I. Structure of fields. J Mech Phys Solids 39: 989–1015
Rice JR (1968). A path independent integral and the approximate analysis of strain concentration by notches and cracks. J Appl Mech 35: 379–386
Rice JR and Rosengren GF (1968). Plane strain deformation near a crack tip in a power-law hardening material. J Mech Phys Solids 16: 1–12
Wallin K (1991). Statistical modeling of fracture in the ductile-to-brittle transition range. In: Blauel, JG and Schwalbe, KH (eds) Defect assessment in components, fundamentals and applications, pp 415–445. Mechanical Engineering Publications, London
Williams ML (1957). On the stress distribution at the base of a stationary crack. J Appl Mech 24: 109–114
Yuan H and Brocks W (1998). Quantification of constraint effects in elastic-plastic crack front fields. J Mech Phys Solids 46: 219–241
Yang S, Chao YJ and Sutton MA (1993). Higher order asymptotic crack tip fields in a power-law hardening material. Eng Fract Mech 45: 1–20
Zhu XK and Leis BN (2006). Bending modified J–Q theory and crack-tip constraint quantification. Int J Fract 141: 115–134
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Hebel, J., Hohe, J., Friedmann, V. et al. Experimental and numerical analysis of in-plane and out-of-plane crack tip constraint characterization by secondary fracture parameters. Int J Fract 146, 173–188 (2007). https://doi.org/10.1007/s10704-007-9160-8
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DOI: https://doi.org/10.1007/s10704-007-9160-8