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

Abstract

ABSTRACT. Fields of stress, strain rate and process zone of a mode I creep crack growth are analyzed by employing damage evolution equations. Damage models for fracture of process zone represented by stress based formulation. Two expressions are presented to describe the stress-sensitive nature of multiaxial rupture behavior. Both damage free and defective creeping solids have been studied. The variation of creep stress and the crack-tip governing parameter in the form of creep In-integral with time and the evolution of creep damage were analyzed by using the FE-model. The effect of the introduced creep stress intensity factor as a function of creep time through the continuum damage mechanics of the creep crack growth are discussed in detail. KEYWORDS. Creep damage; Creep SIF; Multi-axial stress function.Citation: Shlyannikov, V., Tumanov, A., The effect of creep damage formulation on crack tip fields, creep stress intensity factor and crack growth assessments, Frattura ed Integrità Strutturale, 41 (2017) 285-292.

Methods of perturbation theory and their applications in nonlinear fracture mechanics: From the pioneering studies by Hutchinson, Rice and Rosengren until today

“…The present review shows that asymptotic solutions of fracture mechanics problem will be connected with derivation of multiterm asymptotic series expansions for the crack-tip fields using effective computer algorithms and procedures. [50][51][52][53][54][55][56][57] The further development of continuum damage mechanics will probably be connected with experimental determination of active damage accumulation zone in the vicinity of the crack tip via interference-optic methods, 50,61 tomographic scanning techniques, 62 and acoustic emission methods. 63…”

“…Thus, in the framework of continuum damage mechanics, the interaction between a macroscopic crack and distributed microscopic damage can be considered by describing the effect of damage in terms of a continuity parameter ψ (or a damage variable D = 1 − ψ). 10,38,54,55 The The traction free boundary conditions yield the following requirements:…”