Measuring use-related fracture velocity in lithic armatures to identify spears, javelins, darts, and arrows

2011 ◽  
Vol 38 (7) ◽  
pp. 1737-1746 ◽  
Author(s):  
W. Karl Hutchings
Keyword(s):  
Fracture Velocity

scholarly journals Source parameters of earthquakes, and discrimination between earthquakes and nuclear explosions

1968 ◽  
Vol 58 (5) ◽  
pp. 1503-1517
Author(s):  
John B. Davies ◽  
Stewart W. Smith
Keyword(s):  
Fault Plane ◽  
Source Parameters ◽  
Spectral Ratio ◽  
Shallow Earthquake ◽  
Compressional Waves ◽  
Nuclear Explosions ◽  
Deep Earthquakes ◽  
Fracture Velocity ◽  
Fault Length

Abstract The first part of this study describes a technique by which the source parameters of an earthquake can be obtained from the spectrum of compressional waves. The source parameters defined are fault length, fracture velocity, and fault plane attitude. Two large, deep earthquakes are examined using this technique. The source parameters determined compare favorably with those obtained previously using different techniques. In the second section a method is proposed for discrimination between underground explosions and earthquakes. The technique utilizes the ratio of the spectrums of the two classes of events where the path of propagation is common to both. On the basis of the analysis of the SHOAL event and a nearby shallow earthquake it appears that the duration as determined from the spectral ratio is almost 10 times smaller for an explosion than it is for a comparable earthquake.

GLASS-FRACTURE VELOCITY

1939 ◽  
Vol 22 (1-12) ◽  
pp. 302-307 ◽  
Author(s):  
F. E. Barstow ◽  
H. E. Edgerton
Keyword(s):  
Glass Fracture ◽  
Fracture Velocity

A two-dimensional source function for a dynamic brittle bilateral tensile crack

1970 ◽  
Vol 60 (4) ◽  
pp. 1209-1219 ◽  
Author(s):  
Merle E. Hanson ◽  
Allan R. Sanford
Keyword(s):  
Source Function ◽  
Near Field ◽  
Tensile Fracture ◽  
Two Dimensional ◽  
Tensile Crack ◽  
Elastic Continuum ◽  
Fracture Geometry ◽  
Velocity Function ◽  
Final Fracture ◽  
Fracture Velocity

abstract A numerical technic is used to simulate the two-dimensional elastic dynamic characteristics of a bilateral tensile fracture that accelerates, propagates and stops in an elastic continuum. The fracture-velocity function is specified for the calculation. Particle motion in the near field about the final fracture geometry is the result. Motion parallel to the fracture amounts to as much as 50 per cent of the perpendicular motion near the crack. The relaxation begins to occur after the fracture stops and the dynamic elastic radiation from both tips crosses the material.

The Application of the Battelle “Short Formula” to the Determination of Ductile Fracture Arrest Toughness in Gas Pipelines

2000 ◽  
Author(s):  
A. B. Rothwell
Keyword(s):  
Ductile Fracture ◽  
Original Description ◽  
Gas Pipelines ◽  
Research Committee ◽  
Original Intent ◽  
Decompression Wave ◽  
Wide Range ◽  
Fracture Arrest ◽  
Fracture Velocity

Many models and formulae have been put forward, over the years, for the determination of the toughness necessary for the arrest of propagating ductile fracture in gas pipelines. One of the first, and most prominent, was that developed by Battelle Columbus Laboratories for the Pipeline Research Committee of the American Gas Association. As originally embodied, the model involved the comparison of curves expressing the variation of fracture velocity and of decompression wave velocity with pressure (the “two-curve model” — TCM). To aid in analysis, at a time long before a computer was available on every desk, a “short formula” (SF) was developed that provided a good fit to the results of the TCM for a substantial matrix of conditions. This SF has subsequently been adopted by several standards bodies and used widely in the analysis of the results of full-scale burst tests. Since the original description of the derivation of the SF is to be found only in a report to the PRC dating back to the Seventies, many in the pipeline industry today are left without a full appreciation of its range of validity. The present paper briefly discusses the original intent of the SF as a substitute for the TCM, and presents the results of extensive calculations comparing the results of the two. It can be concluded that the SF provides an excellent estimate of the results of the TCM over a very wide range of design and operating parameters, within the limitations inherent in the method.

The maximum fracture velocity of silicon

1971 ◽  
Vol 6 (5) ◽  
pp. 390-394 ◽  
Author(s):  
J. H. Greenwood
Keyword(s):  
Fracture Velocity

Fracture Propagation in Underwater Gas Pipelines

1986 ◽  
Vol 108 (1) ◽  
pp. 29-34 ◽  
Author(s):  
W. A. Maxey
Keyword(s):  
Ductile Fracture ◽  
Pipe Wall ◽  
Fracture Propagation ◽  
Full Scale ◽  
Gas Pipelines ◽  
Buried Pipelines ◽  
Nitrogen Gas ◽  
Line Pipe ◽  
Fracture Velocity

Two full-scale ductile fracture propagation experiments on segments of line pipe pressurized with nitrogen gas have been conducted underwater at a depth of 40 ft (12 m) to evaluate the ductile fracture phenomenon in underwater pipelines. The pipes were 22-in. (559-mm) diameter and 42-in. (1067-mm) diameter. Fracture velocities were measured and arrest conditions were observed. The overpressure in the water surrounding the pipe resulting from the release of the compressed nitrogen gas contained in the pipe was measured in both experiments. The overpressure in the water reduces the stress in the pipe wall and thus slows down the fracture. In addition, the water surrounding the pipe appears to be more effective than soil backfill in producing a slower fracture velocity. Both of these effects suggest a greater tendency toward arrest for a pipeline underwater than would be the case for the same pipeline buried in soil onshore. Further verification of this effect is planned and a modified version of the existing model for predicting ductile fracture in buried pipelines will be developed for underwater pipelines.

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