Analysis of Load-Displacement Relationship to Determine J-R Curve and Tearing Instability Material Properties

Ernst, Hugo A.; Paris, Paul C.; Rossow, M. P.; Hutchinson, J.W.

doi:10.1520/stp34937s

Cited by 98 publications

(38 citation statements)

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“…The early load separation analysis was performed by Ernst et al [114]. About 10 years later, Sharobeam and Landes [115,116] strictly verified the existence of load separation relationship for ductile materials using detailed experimental investigations and numerical finite element analyses.…”

Section: Early J Estimation and G-factor Equationsmentioning

confidence: 98%

“…An alternative technique named normalization method was developed to estimate instantaneous crack length directly from the load versus LLD data record. The basis is the principle of load separation [114][115][116] and the key curve method [126,144]. This technique does not require any devices for online monitoring of crack growth, but suggests an individual calibration curve to be used to determine instantaneous crack size.…”

Section: Normalization Data Reduction Techniquementioning

confidence: 99%

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Review of fracture toughness (G, K, J, CTOD, CTOA) testing and standardization

Zhu

Joyce

2012

Engineering Fracture Mechanics

611

126

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Stress intensity factor Energy release rate CTOD CTOA J-integral J-R curve K-R curve ASTM standard a b s t r a c tThe present paper gives a technical review of fracture toughness testing, evaluation and standardization for metallic materials in terms of the linear elastic fracture mechanics as well as the elastic-plastic fracture mechanics. This includes the early investigations and recent advances of fracture toughness test methods and practices developed by American Society for Testing and Materials (ASTM). The review describes the most important fracture mechanics parameters: the elastic energy release rate G, the stress intensity factor K, the Jintegral, the crack-tip opening displacement (CTOD) and the crack-tip opening angle (CTOA) from the basic concept, definition, to experimental estimation, test methods and ASTM standardizing practices. Attention is paid to guidelines on how to choose an appropriate fracture parameter to characterize fracture toughness for the material of interest, and how to measure the fracture toughness value defined either at a critical point or in a resistance curve format using laboratory specimens. The relevant ASTM fracture toughness test standards considered in this paper are E399 for K Ic testing, E561 for K-R curve testing, E813 for J Ic testing, E1152 for J-R curve testing, E1737 for J Ic and J-R curve testing, E1290 for CTOD (d) testing, a combined common test standard E1820 for measuring the three parameters of K, J and d, E1921 for the transition reference temperature T 0 testing and the master curve of cleavage toughness K Jc testing, and E2472 for CTOA testing. The effects of loading rate, temperature and crack-tip constraint on fracture toughness as well as fracture instability analysis are also reviewed.

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Section: Early J Estimation and G-factor Equationsmentioning

confidence: 98%

Section: Normalization Data Reduction Techniquementioning

confidence: 99%

Review of fracture toughness (G, K, J, CTOD, CTOA) testing and standardization

Zhu

Joyce

2012

Engineering Fracture Mechanics

611

126

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“…The plastic part can then be derived by dimensional analysis assuming that the plasticity is confined to the characteristic length of the uncracked ligament, o b , for any medium containing a crack. A second assumption regarding the dimensional integrand states that separation of variables can be applied (Ernst et al, 1979;Merkle and Corten, 1974). Moreover, it was later shown that the geometrical parameters associated to J can be estimated empirically for a compact tension specimen (Clarke and Landes, 1979).…”

Section: J-integralmentioning

confidence: 99%

“…In this incremental view of the crack initiation process, the energy release that occurs can further excite transient dynamic motion as well as multispectral (e.g. thermal) energy dissipation, which are both part of the associated energy redistribution (Döll, 1984;Ernst et al, 1979;Gross et al, 1993;Sharon et al, 1996). In this context, the experimental work by Döll and Gross et al suggested that most of the stored energy is dissipated as heat and that only a fraction (approximately 3%) of the total fracture energy could be associated with AE (Döll, 1984;Gross et al, 1993;Hack et al, 1989).…”

Section: Introductionmentioning

confidence: 99%

Energy dissipation via acoustic emission in ductile crack initiation

et al. 2016

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This article presents a modeling approach to estimate the energy release due to ductile crack initiation in conjunction to the energy dissipation associated with the formation and propagation of transient stress waves typically referred to as Acoustic Emission. To achieve this goal, a ductile fracture problem is investigated computationally using the Finite Elements Method based on a compact tension geometry under Mode I loading conditions. To quantify the energy dissipation associated with Acoustic Emission, a crack increment is produced given a pre-determined notch size in a 3D cohesive-based extended finite element model. The computational modeling methodology consists of defining a damage initiation state from static simulations and linking such state to a dynamic formulation used to evaluate wave propagation and related energy redistribution effects.The model relies on a custom traction separation law constructed using full field deformation measurements obtained experimentally using the Digital Image Correlation method. The amount of energy release due to the investigated first crack increment is evaluated through three different approaches both for verification purposes and to produce an estimate of the portion of the energy that radiates away from the crack source in the form of transient waves. The results presented herein propose an upper bound for the energy dissipation associated to Acoustic Emission, which could assist the interpretation and implementation of relevant nondestructive evaluation methods and the further enrichment of the understanding of effects associated with fracture.

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“…In LBB analysis, as an integrity analysis method against instability fracture of cracked piping, J-integral, tearing modulus (J/T) method (Ernst et al, 1979(Ernst et al, , 1981 and the limit load method were used. While the limit load method is appropriate for the analysis of stainless steel piping, J/T method is appropriate for the analysis of both carbon and stainless steel piping.…”

Section: Importance Of J-r Curve For Long Crack Extensionmentioning

confidence: 99%