scholarly journals Investigation on brittle crack propagation and arrest behaviour under high crack driving force in steel

2018 ◽  
Vol 13 ◽  
pp. 116-122
Author(s):  
Fuminori Yanagimoto ◽  
Kazuki Shibanuma ◽  
Teppei Okawa ◽  
Katsuyuki Suzuki ◽  
Shuji Aihara
Keyword(s):  
Crack Propagation ◽  
Driving Force ◽  
Brittle Crack ◽  
Crack Driving Force ◽  
High Crack ◽  
Crack Propagation And Arrest

The crack driving force for fatigue crack propagation

1993 ◽  
Vol 44 (5) ◽  
pp. 821-829 ◽  
Author(s):  
R. Pippan
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Driving Force ◽  
Crack Driving Force

scholarly journals Study on Brittle Crack Propagation and Arrest Behavior in Plates and Beams Structure (1 st. report)

1981 ◽  
Vol 1981 (149) ◽  
pp. 211-218
Author(s):  
Takeshi Kanazawa ◽  
Susumu Machida ◽  
Hiroshi Yajima ◽  
Hajime Kawano
Keyword(s):  
Crack Propagation ◽  
Brittle Crack ◽  
Crack Propagation And Arrest

Steady-State Crack Propagation in Pressurized Pipelines

1977 ◽  
Vol 99 (1) ◽  
pp. 112-121 ◽  
Author(s):  
C. Popelar ◽  
A. R. Rosenfield ◽  
M. F. Kanninen
Keyword(s):  
Steady State ◽  
Crack Propagation ◽  
Driving Force ◽  
Crack Arrest ◽  
Operating Conditions ◽  
Unstable Crack ◽  
Crack Driving Force ◽  
Plastic Yield ◽  
Pressurized Pipelines ◽  
Full Scale Tests

Previous work at Battelle-Columbus on the development of a theoretical model for unstable crack propagation and crack arrest in a pressurized pipeline is extended in this paper by including the effect of backfill. The approach being developed involves four essential aspects of crack propagation in pipelines. These four components of the problem are: 1 – a shell theory characterization of the dynamic deformation of a pipe with a plastic yield-hinge behind an axially propagating crack, 2 – a fluid-mechanics treatment of the axial variations in the gas pressure acting on the pipe walls, 3 – an energy-based dynamic fracture mechanics formulation for the crack-driving force, and 4 – measured values of the dynamic energy absorption rate for pipeline steels. Comparisons given in the paper show that the steady-state crack speeds predicted by the model are in reasonably good agreement with the crack speeds measured in full-scale tests, both with and without backfill. The analysis further reveals the existence of a maximum steady-state crack-driving force as a function of the basic mechanical properties of the pipe steel and the pipeline goemetry and operating conditions. Quantitative estimates of this quantity provided by the model offer a basis for comparison with the empirical crack-arrest design criteria for pipelines developed by AISI, the American Gas Association, the British Gas Council, and British Steel. These are also shown to be in substantial agreement with the predictions of the model developed in this paper.

Effect of Notch Type in Drop-Weight Tear Test Specimen on Crack Propagation and Arrest Behavior

2018 ◽  
Author(s):  
Satoshi Igi ◽  
Toshihiko Amano ◽  
Takahiro Sakimoto ◽  
Yasuhiro Shinohara ◽  
Tetsuya Tagawa
Keyword(s):  
Crack Propagation ◽  
Large Scale ◽  
Crack Arrest ◽  
Brittle Crack ◽  
Chevron Notch ◽  
Drop Weight ◽  
Drop Weight Tear Test ◽  
Shear Area ◽  
The Impact ◽  
Crack Propagation And Arrest

The drop-weight tear test (DWTT) has been widely used to evaluate the resistance of linepipe steels against brittle fracture propagation. However, in the recent years there is an ambiguity in its evaluation if inverse fracture appears on the specimen fracture surfaces. Although cause of the inverse fracture is not fully understood, compressive pre-straining near the impact hammer and existing tiny split have been discussed as a possible cause. In this paper, machined notch in brittle weld DWTT for X65 was performed and compared with various notch types of DWTTs such as conventional DWTT specimen with a pressed notch (PN), a chevron notch (CN) and a static pre-cracked (SPC). The fracture appearances were compared with different strength X65 - X80 grades linepipes and with different initial notch types. The frequency of the inverse fracture appeared in these DWTTs were different in each material and each specimen types, but there were no cases where the inverse fracture did not occurs. The purpose of DWTT is to evaluate the brittle crack arrestability of the material in a pressurized linepipe. A large scale brittle crack arrest test, so called West Jeferson test is generally used to reproduce crack propagation and arrest behavior in an actual pipeline material. A middle scale test so called Crack Arrest Temperature (CAT) test was also proposed to check the shear area fraction measured in DWTT with API rating with that the local shear lip thickness fraction in those tests. CAT test can well reproduce crack propagation and arrest behavior under the condition of brittle crack initiation from the initial notch.

scholarly journals Fracture Mechanical Modeling of Brittle Crack Propagation and Arrest of Steel (3)

1996 ◽  
Vol 1996 (179) ◽  
pp. 389-398 ◽  
Author(s):  
Shuji Aihara ◽  
Susumu Machida ◽  
Hitoshi Yoshinari ◽  
Yutaka Tsuchida
Keyword(s):  
Crack Propagation ◽  
Mechanical Modeling ◽  
Brittle Crack ◽  
Crack Propagation And Arrest

Mixed Mode Brittle Crack Propagation Modelling in a PWR Vessel Steel

2008 ◽  
Author(s):  
B. Prabel ◽  
S. Marie ◽  
A. Combescure
Keyword(s):  
Finite Element ◽  
Stress Field ◽  
Crack Propagation ◽  
Rapid Growth ◽  
Mixed Mode ◽  
Crack Path ◽  
Crack Tip ◽  
Crack Speed ◽  
Brittle Crack ◽  
Crack Propagation And Arrest

R&D activities and some development are performed at CEA on the brittle crack propagation and arrest. Phenomena occurring after the initiation of a brittle crack are not yet well understood. Absence of model able to predict the rapid growth of a brittle crack motivates this study. Due to the rapid growth of the crack, inertial effects and dynamic fracture should be considered. Assumption of a linear elastic solid are often preferred, but when plasticity of the material become non negligible (which is the case in the vicinity of the transition zone), these models become more limited. That’s why the paper presented here deals with dynamic crack propagation in elastic-viscoplastic material and aims at proposing a model able to predict the brittle crack propagation and arrest. To this end, experimental work is carried out for different geometries made of french RPV ferritic steel. Compact Tension specimens with different thickness, isothermal rings under compression with different positions of the initial defect to study also a mixed mode configuration. The test conditions and mains results (crack initiation, crack velocity measurements, ...) are collected and presented in a first part of the paper. To model efficiently the crack propagation in the Finite Element calculation, the eXtended Finite Element Method (X-FEM) implemented in the CEA F.E. software CAST3M is described in the second part of the paper. Thanks to this numerical technique, the crack path does not need to follow the element edges and the crack progress is directly incorporated in the degrees of freedom of the elements crossed by the crack. A two-steps methodology is presented in the third and fourth parts of this paper. The first step consider only the CT specimen, experimental crack speed evolution with time is imposed in numerical simulations. Energy terms and stress field at the crack tip are evaluated and discussed to build up a criterion. Then, the criterion identified on CT specimen is used in a second step as a predictive model to simulate crack propagation for each geometry studied (CT, ring in both mode I and mixed mode). In particular, crack propagation models based on the stress field evaluated at the crack tip and on a critical cleavage stress dependent on the strain rate, exhibit very good agreement with experimental data in term of crack speed, crack path and crack length at arrest. The mixed mode case is discussed in detail because to be pertinent, a model of brittle crack propagation should not only give the crack speed, but also its preferred direction of evolution.

Instability Analysis for Thermal Barrier Coating by Fracture Mechanical Modelings

2007 ◽  
Author(s):  
Amar N. Kumar ◽  
Amiya Nayak ◽  
Alok R. Patnaik ◽  
Xijia Wu ◽  
Prakash C. Patnaik
Keyword(s):  
Crack Initiation ◽  
Driving Force ◽  
Fracture Resistance ◽  
Crack Driving Force ◽  
Propagation Behavior ◽  
Barrier Coating ◽  
Order Of Magnitude ◽  
High Crack ◽  
Energy Balance Approach ◽  
Tbc Systems

Two simplistic models based on fracture mechanics considerations are used to advance the understanding of instability conditions in TBC systems. First model assumes isostrain behavior at and prior to the onset of crack initiation and is based on elastic energy balance approach. The other model is used for layer buckling and crack propagation behavior. The analysis for crack initiation suggests that the crack tip driving force, KI can reach a high value that is comparable to the fracture resistance of the coating material at and near the TBC/TGO interface even for a small nominal applied stress. The stresses required for the crack driving force (KI or GI) exceeding the fracture resistance of TBC materials are found to be in the range of 0.05 to 0.5 GPa. This appears to be an order of magnitude lower than the reported tangential tensile stress values of 1 to 2 GPa, but matches closely with the simulated transverse stress. High crack driving force resulting from low stress and small size defects (around 2 microns) facilitates early crack initiation in TBC system.

scholarly journals Study on Brittle Crack Propagation and Arrest Behavior in Plates and Beams Structure (2nd Report)

1983 ◽  
Vol 1983 (153) ◽  
pp. 316-321
Author(s):  
Hiroshi Yajima ◽  
Hajime Kawano ◽  
Yoshio Urabe
Keyword(s):  
Crack Propagation ◽  
Brittle Crack ◽  
Crack Propagation And Arrest
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