Further considerations on the development of Surface Cracks under stable crack extension

1983 ◽  
Vol 14 (2) ◽  
pp. 41-44 ◽  
Author(s):  
B. Rüttenauer ◽  
W. Setz ◽  
L. Grüeter
Keyword(s):  
Crack Extension ◽  
Surface Cracks

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.

Experimental and Numerical Investigation of Sub-Clad and Surface Cracks in Cladded Components

2008 ◽  
Author(s):  
Jo¨rg Hohe ◽  
Marcus Brand ◽  
Dieter Siegele
Keyword(s):  
Numerical Simulation ◽  
Heat Treatment ◽  
Residual Stress ◽  
Crack Extension ◽  
Fracture Behavior ◽  
Large Scale ◽  
Ferritic Steels ◽  
Surface Cracks ◽  
Residual Stress Field ◽  
Treatment Processes

The present study is concerned with the fracture behavior of sub-clad and surface cracks in components consisting of ferritic steels with an austenitic welded cladding. For this purpose, two tests on large scale specimens have been performed. The residual stress field has been determined by means of a numerical simulation of the welding and heat treatment processes. Based on the results, a numerical simulation of the component tests was performed in order to enable a fracture mechanics assessment of the conditions leading to crack initiation and arrest in the ferritic and austenitic regions. It was observed that in the present tests failure was initiated in the ferritic material whereas the austenitic cladding remained stable even in the case of a limited crack extension in the ferritic base metal.

Toughness determination of zirconia toughened alumina ceramics from growth of indentation-induced cracks

1996 ◽  
Vol 11 (12) ◽  
pp. 3057-3063 ◽  
Author(s):  
D. Basu ◽  
B. K. Sarkar
Keyword(s):  
Stress Intensity ◽  
Crack Extension ◽  
Polished Surface ◽  
Surface Cracks ◽  
Transformation Toughening ◽  
Alumina Ceramics ◽  
Bend Tests ◽  
Point Bend ◽  
Zirconia Toughened Alumina

Short surface cracks were generated by Vickers indentation on the polished surface of alumina and different zirconia toughened alumina (ZTA) specimens, and their morphology was studied by serial sectioning. These cracks were grown in three-point bend tests under stepwise loading, and variation of toughness with crack extension was plotted to graphically separate the contributions from residual stress intensity and applied stress intensity factors. The plateau toughness determined from the intercept height of the crack extension plots exhibited an upward trend with zirconia content up to 15 vol % ZrO2 addition in the composition, which was proportional to the fraction of transformable tetragonal grains contributing to transformation toughening.

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