A Study of Shear Crack Propagation in Gas-Pressurized Pipelines

1982 ◽  
Vol 104 (4) ◽  
pp. 338-343 ◽  
Author(s):  
E. Sugie ◽  
M. Matsuoka ◽  
T. Akiyama ◽  
H. Mimura ◽  
Y. Kawaguchi
Keyword(s):  
Crack Propagation ◽  
Crack Velocity ◽  
Shear Crack ◽  
Controlled Rolling ◽  
Full Scale ◽  
Pipe Length ◽  
On Line ◽  
Pressurized Pipelines ◽  
Quenching And Tempering ◽  
Crack Propagation And Arrest

Full-scale burst tests were carried out five times on line pipes of 48 in. o.d. × 0.720 in. w.t., Grad. X-70 manufactured by the controlled rolling and the quenching and tempering processes. It was found that the critical notch ductility for arresting a shear crack depends on the pipe length within which the crack is to be arrested. This result is well explained by solving the equation which governs change of crack velocity. The behavior of shear crack propagation and arrest can be well analyzed regardless of the existence or nonexistence of separation by Charpy energy.

Respirometry for determination of the influents SS-concentration

1996 ◽  
Vol 33 (1) ◽  
pp. 311-323 ◽  
Author(s):  
A. Witteborg ◽  
A. van der Last ◽  
R. Hamming ◽  
I. Hemmers
Keyword(s):  
Experimental Design ◽  
Activated Sludge ◽  
Substrate Concentration ◽  
Full Scale ◽  
Activated Sludge Process ◽  
Respiration Rates ◽  
On Line ◽  
Large Measurement ◽  
Set Up

A method is presented for determining influent readily biodegradable substrate concentration (SS). The method is based on three different respiration rates, which can be measured with a continuous respiration meter which is operated in a cyclic way. Within the respiration meter nitrification is inhibited through the addition of ATU. Simulations were used to develop the respirometry set-up and decide upon the experimental design. The method was tested as part of a large measurement programme executed at a full-scale plant. The proposed respirometry set-up has been shown to be suitable for a semi-on-line determination of an influent SS which is fully based on the IAWQ #1 vision of the activated sludge process. The YH and the KS play a major role in the principle, and should be measured directly from the process.

Automatic buffer capacity based sensor for effluent quality monitoring

1996 ◽  
Vol 33 (1) ◽  
pp. 81-87
Author(s):  
L. Van Vooren ◽  
P. Willems ◽  
J. P. Ottoy ◽  
G. C. Vansteenkiste ◽  
W. Verstraete
Keyword(s):  
Wastewater Treatment ◽  
Buffer Capacity ◽  
Wastewater Treatment Plants ◽  
Data Interpretation ◽  
Full Scale ◽  
Quality Monitoring ◽  
Effluent Quality ◽  
Capacity Curves ◽  
On Line

The use of an automatic on-line titration unit for monitoring the effluent quality of wastewater plants is presented. Buffer capacity curves of different effluent types were studied and validation results are presented for both domestic and industrial full-scale wastewater treatment plants. Ammonium and ortho-phosphate monitoring of the effluent were established by using a simple titration device, connected to a data-interpretation unit. The use of this sensor as the activator of an effluent quality proportional sampler is discussed.

Axial crack propagation and arrest in a pressurized cylinder: An experimental-numerical analysis

1999 ◽  
Vol 39 (4) ◽  
pp. 256-264 ◽  
Author(s):  
M. Kosai ◽  
A. Shimamoto ◽  
C. T. Yu ◽  
A. S. Kobayashi ◽  
P. W. Tan
Keyword(s):  
Numerical Analysis ◽  
Crack Propagation ◽  
Axial Crack ◽  
Pressurized Cylinder ◽  
Crack Propagation And Arrest

Crack Growth During Full Scale Reeling Simulation of Pipes With Girth Welds

2004 ◽  
Author(s):  
Oddvin O¨rjasaeter ◽  
Olav Jan Hauge ◽  
Guy Ba¨rs ◽  
Per Egil Kvaale
Keyword(s):  
Crack Propagation ◽  
Crack Growth ◽  
High Strain ◽  
High Stress ◽  
Strain Range ◽  
Full Scale ◽  
Small Scale ◽  
Final Fracture ◽  
Lack Of Fusion ◽  
Girth Welds

Installation of pipelines by reeling has proved to be an effective method. However, the pipe bending results in very high stress and strain and cannot be handled by conventional design rules, as stated in design codes, e.g. [2]: High strain crack growth must be assessed according to specific case-by-case selected criterions. In the present work the performance of 10” and 12 3/4” pipes with typical weld defects is studied — from initiation of cracks at notches to final fracture. Information was obtained from several sources: full scale cyclic bending of pipes, FE simulations, and small-scale tests. The plasticity during reeling operations results in substantial non-linear behavior due to varying cross section properties, cyclic creep, and different material response at tensile and compression side of the pipe. Hence, a full scale reeling simulation must be carefully planned and include sufficient tolerances. Critical cracks in pipe girth welds initiate mainly from the surface (undercuts, lack of penetration, or lack of fusion), but potentially also internally (lack of fusion or large pores). Various configurations of these parameters were investigated in full scale pipe tests. It was possible to verify both crack propagation during the reeling cycles, and the point of final fracture (for ECA verifications). In pipe design on must assure safe conditions for both reeling operations and for later in-service loading. Proper design tools must be available. Several methods for high strain crack growth analysis were considered and also compared to small-scale specimen data. Conventional strain-life methodology failed to predict the crack propagation accurately. A new approach including a tensile strain range parameter offered promising results.

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

scholarly journals A Study of Shear Crack Propagation in Spring-loaded DCB Testing

1978 ◽  
Vol 64 (7) ◽  
pp. 937-946 ◽  
Author(s):  
Yoshiyuki KURITA ◽  
Toshiya AKIYAMA ◽  
Takahiro FUJITA ◽  
Fusao KOSHIGA
Keyword(s):  
Crack Propagation ◽  
Shear Crack
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