scholarly journals Separation of Crack Extension Modes in Composite Delamination Problems

2009 ◽  
pp. 324-324-19 ◽  
Author(s):  
JL Beuth ◽  
SH Narayan
Keyword(s):  
Crack Extension

Ductile Crack Extension Analysis for X80 Bending Deformation Using Damage-Based Model

2014 ◽  
Author(s):  
Satoshi Igi ◽  
Mitsuru Ohata ◽  
Takahiro Sakimoto ◽  
Kenji Oi ◽  
Joe Kondo
Keyword(s):  
Plastic Strain ◽  
Simulation Model ◽  
Crack Growth ◽  
Crack Extension ◽  
Damage Model ◽  
Stress Triaxiality ◽  
Crack Growth Behavior ◽  
Ductile Crack ◽  
Ductile Crack Growth ◽  
Notch Tip

This paper presents experimental and analytical results focusing on the strain limit of X80 linepipe. Ductile crack growth behavior from a girth weld notch is simulated by FE analysis based on a proposed damage model and is compared with the experimental results. The simulation model for ductile crack growth accompanied by penetration through the wall thickness consists of two criteria. One is a criterion for ductile crack initiation from the notch-tip, which is described by the plastic strain at the notch tip, because the onset of ductile cracking can be expressed by constant plastic strain independent of the shape and size of the components and the loading mode. The other is a damage-based criterion for simulating ductile crack extension associated with damage evolution influenced by plastic strain in accordance with the stress triaxiality ahead of the extending crack tip. The proposed simulation model is applicable to prediction of ductile crack growth behaviors from a circumferentially-notched girth welded pipe with high internal pressure, which is subjected to tensile loading or bending (post-buckling) deformation.

A criterion for crack extension II

1982 ◽  
Vol 16 (7) ◽  
pp. 775-779 ◽  
Author(s):  
N. Louat
Keyword(s):  
Crack Extension

Application of the R-Curve Concept to Fatigue Crack Growth

1978 ◽  
Vol 100 (4) ◽  
pp. 416-420 ◽  
Author(s):  
D. P. Wilhem ◽  
M. M. Ratwani
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Crack Extension ◽  
Stress Ratio ◽  
Cyclic Stress ◽  
Crack Growth Resistance ◽  
Resistance Curve ◽  
Cyclic Stress Ratio ◽  
Wide Range

Crack growth resistance for both static (rising load) and for cyclic fatigue crack growth has been shown to be a continuous function over a range of 0.1 μm to 10 cm in crack extension for 2024-T3 aluminum. Crack growth resistance to each fatigue cycle of crack extension is shown to approach the materials ordinary undirectional static crack resistance value when the cyclic stress ratio is zero. The fatigue crack extension is averaged over many cycles and is correlated with the maximum value of the crack tip stress intensity, Kmax. A linear plot of crack growth resistance for fatigue and static loading data shows similar effects of thickness, stress ratio, and other parameters. The effect of cyclic stress ratio on crack growth resistance for 2219 aluminum indicates the magnitude of differences in resistance when plotted to a linear scale. Prediction of many of these trends is possible using one of several available crack growth data correlating techniques. It appears that a unique resistance curve, dependent on material, crack orientation, thickness, and stress/physical environment, can be developed for crack extensions as small as 0.076 μm (3 μ inches). This wide range, crack growth resistance curve is seen of immense potential for use in both fatigue and fracture studies.

A statistical model for ubiquitiformal crack extension in quasi-brittle materials

2017 ◽  
Vol 228 (7) ◽  
pp. 2725-2732 ◽  
Author(s):  
Jing-Yan Li ◽  
Zhuo-Cheng Ou ◽  
Yi Tong ◽  
Zhuo-Ping Duan ◽  
Feng-Lei Huang
Keyword(s):  
Statistical Model ◽  
Crack Extension ◽  
Brittle Materials

Study on the Prediction of the Maximum Crack Extension Location for Surface Cracks

2016 ◽  
Vol 853 ◽  
pp. 3-7
Author(s):  
Jie Yang
Keyword(s):  
Crack Extension ◽  
Equivalent Plastic Strain ◽  
Simulation Method ◽  
Resistance Force ◽  
Surface Cracks ◽  
Constraint Effect ◽  
Crack Driving Force ◽  
Suitable Parameter ◽  
Maximum Crack ◽  
Finite Element Numerical Simulation

In this paper, the plate with different surface cracks (different constraints) was selected, the finite element numerical simulation method was used to mod el the J-integral and the equivalent plastic strain (εp) distributions ahead of crack front, after the unified constraint characterization parameter Ap was calculated, a new parameter which considered both J-integral and constraint effectwasdefined and a new methodology was provided to ensure the maximum crack extension location of surface crack. The results show that if the location of the maximum is defined as the maximum crack extension location, the prediction results is consistent with the measured results in experiments. The parameter which considered both crack driving force and material resistance force is a suitable parameter, and can be used to predict the maximum crack extension location.

Crack-Extension Force for a Part-Through Crack in a Plate

1962 ◽  
Vol 29 (4) ◽  
pp. 651-654 ◽  
Author(s):  
G. R. Irwin
Keyword(s):  
Stress Field ◽  
Crack Extension ◽  
Crack Opening ◽  
Elliptical Crack ◽  
Field Parameter ◽  
Experimental Measurements ◽  
Boundary Points ◽  
Crack Extension Force ◽  
Extension Force

The crack stress-field parameter K and crack-extension force G at boundary points of a flat elliptical crack may be derived from knowledge that normal tension produces an ellipsoidal crack opening. Rough correction procedures can be employed to adapt this result for application to a part-through crack in a plate subjected to tension. Experimental measurements suggest this adapted result has a useful range of accuracy.

Crack Growth by Dimensional Reduction Methods

2012 ◽  
Vol 525-526 ◽  
pp. 17-20
Author(s):  
P.H. Wen ◽  
M.H. Aliabadi
Keyword(s):  
Crack Growth ◽  
Dimensional Reduction ◽  
Crack Extension ◽  
Initial Growth ◽  
Stress Criterion ◽  
The Maximum Principle ◽  
Reduction Methods ◽  
Small Increments ◽  
Crack Growth Path ◽  
Crack Paths

This paper presents a new fatigue crack growth prediction by using the dimensional reduction methods including the dual boundary element method (DBEM) and element-free Galerkin method (EFGM) for two dimensional elastostatic problems. One crack extension segment, i.e. a segment of arc, is introduced to model crack growth path. Based on the maximum principle stress criterion, this new prediction procedure ensures that the crack growth is smooth everywhere except the initial growth and the stress intensity factor of mode II is zero for each crack extension. It is found that the analyses of crack paths using coarse/large size of crack extension are in excellent agreement with analyses of the crack paths by the tangential method with very small increments of crack extension.

Determination of Fracture Toughness and K-R Curve for 2524-T3 Aluminum Alloy

2011 ◽  
Vol 291-294 ◽  
pp. 1039-1042
Author(s):  
Wei Xie ◽  
Shao Wei Tu ◽  
Qi Qing Huang ◽  
Ya Zhi Li
Keyword(s):  
Fracture Toughness ◽  
Aluminum Alloy ◽  
Stress Fracture ◽  
Test Data ◽  
Plane Stress ◽  
Crack Extension ◽  
Room Temperature ◽  
Mode I ◽  
Average Value

In the present work, the resistance to crack extension of 2524-T3 aluminum alloy under Mode I loading was studied by using the middle-cracked tension M (T) specimens. The curve, plane-stress fracture toughness and apparent plane-stress fracture toughness were calculated by test data. The average value of measured fracture toughness at room temperature was 161 MPam1/2. The results and conclusions can be referred in airplane skin design.

An Experimental Investigation of Fracture Criteria for Combined Extension and Bending

1969 ◽  
Vol 91 (4) ◽  
pp. 841-849 ◽  
Author(s):  
R. H. Wynn ◽  
C. W. Smith
Keyword(s):  
Experimental Investigation ◽  
Lower Bound ◽  
Crack Closure ◽  
Crack Extension ◽  
Fracture Criterion ◽  
Fracture Criteria ◽  
Cylindrical Bending ◽  
Cracked Plates

Experiments were performed on cracked plates loaded in combined extension and approximately cylindrical bending. A fracture criterion was developed from the Sih-Hartranft bending theory, which, when modified to account for precatastrophic crack extension, agreed well with the experiments in regions where the crack remained open at fracture and appeared to provide a lower bound in the region where crack closure occurred.

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