Adiabatic shear localization: occurrence, theories, and applications

<div id="synopsistext" dir="ltr" class="sa"><img src="http://img2.imagesbn.com/p/9780080412665_p0_v1_s260x420.gif" border="0" alt="" hspace="8" width="100" height="153" align="left" />Adiabatic shear localization is a mode of failure that occurs in dynamic loading. It is characterized by thermal softening occurring over a very narrow region of a material and is usually a precursor to ductile fracture and catastrophic failure. This reference source is the first detailed study of the mechanics and modes of adiabatic shear localization in solids, and provides a systematic description of a number of aspects of adiabatic shear banding. The inclusion of the appendices which provide a quick reference section and a comprehensive collection of thermomechanical data allows rapid access and understanding of the subject and its phenomena. The concepts and techniques described in this work can usefully be applied to solve a multitude of problems encountered by those investigating fracture and damage in materials, impact dynamics, metal working and other areas. This reference book has come about in response to the pressing demand of mechanical and metallurgical engineers for a high quality summary of the knowledge gained over the last twenty years. While fulfilling this requirement, the book is also of great interest to academics and researchers into materials performance.</div><div dir="ltr" class="sa"><h3 id="yui_3_7_3_1_1356267270901_1326">Table of Contents</h3><table border="0" id="yui_3_7_3_1_1356267270901_1331"><tbody id="yui_3_7_3_1_1356267270901_1330"><tr id="yui_3_7_3_1_1356267270901_1329"><td id="yui_3_7_3_1_1356267270901_1601" width="20%">1</td><td id="yui_3_7_3_1_1356267270901_1328" width="70%">Introduction</td><td width="10%" align="right">1</td></tr><tr id="yui_3_7_3_1_1356267270901_1334"><td id="yui_3_7_3_1_1356267270901_1600" width="20%">1.1</td><td id="yui_3_7_3_1_1356267270901_1333" width="70%">What is an Adiabatic Shear Band?</td><td width="10%" align="right">1</td></tr><tr id="yui_3_7_3_1_1356267270901_1336"><td id="yui_3_7_3_1_1356267270901_1599" width="20%">1.2</td><td id="yui_3_7_3_1_1356267270901_1335" width="70%">The Importance of Adiabatic Shear Bands</td><td width="10%" align="right">6</td></tr><tr id="yui_3_7_3_1_1356267270901_1338"><td id="yui_3_7_3_1_1356267270901_1598" width="20%">1.3</td><td id="yui_3_7_3_1_1356267270901_1337" width="70%">Where Adiabatic Shear Bands Occur</td><td width="10%" align="right">10</td></tr><tr id="yui_3_7_3_1_1356267270901_1340"><td id="yui_3_7_3_1_1356267270901_1571" width="20%">1.4</td><td id="yui_3_7_3_1_1356267270901_1339" width="70%">Historical Aspects of Shear Bands</td><td width="10%" align="right">11</td></tr><tr id="yui_3_7_3_1_1356267270901_1422"><td id="yui_3_7_3_1_1356267270901_1570" width="20%">1.5</td><td id="yui_3_7_3_1_1356267270901_1421" width="70%">Adiabatic Shear Bands and Fracture Maps</td><td width="10%" align="right">14</td></tr><tr id="yui_3_7_3_1_1356267270901_1565"><td id="yui_3_7_3_1_1356267270901_1566" width="20%">1.6</td><td id="yui_3_7_3_1_1356267270901_1564" width="70%">Scope of the Book</td><td width="10%" align="right">20</td></tr><tr id="yui_3_7_3_1_1356267270901_1569"><td id="yui_3_7_3_1_1356267270901_1568" width="20%">2</td><td id="yui_3_7_3_1_1356267270901_1602" width="70%">Characteristic Aspects of Adiabatic Shear Bands</td><td width="10%" align="right">24</td></tr><tr id="yui_3_7_3_1_1356267270901_1593"><td id="yui_3_7_3_1_1356267270901_1592" width="20%">2.1</td><td id="yui_3_7_3_1_1356267270901_1603" width="70%">General Features</td><td width="10%" align="right">24</td></tr><tr id="yui_3_7_3_1_1356267270901_1573"><td id="yui_3_7_3_1_1356267270901_1572" width="20%">2.2</td><td width="70%">Deformed Bands</td><td width="10%" align="right">27</td></tr><tr id="yui_3_7_3_1_1356267270901_1591"><td id="yui_3_7_3_1_1356267270901_1590" width="20%">2.3</td><td width="70%">Transformed Bands</td><td width="10%" align="right">28</td></tr><tr id="yui_3_7_3_1_1356267270901_1589"><td id="yui_3_7_3_1_1356267270901_1588" width="20%">2.4</td><td width="70%">Variables Relevant to Adiabatic Shear Banding</td><td width="10%" align="right">35</td></tr><tr id="yui_3_7_3_1_1356267270901_1575"><td id="yui_3_7_3_1_1356267270901_1574" width="20%">2.5</td><td width="70%">Adiabatic Shear Bands in Non-Metals</td><td width="10%" align="right">44</td></tr><tr><td width="20%">3</td><td width="70%">Fracture and Damage Related to Adiabatic Shear Bands</td><td width="10%" align="right">54</td></tr><tr><td width="20%">3.1</td><td width="70%">Adiabatic Shear Band Induced Fracture</td><td width="10%" align="right">54</td></tr><tr><td width="20%">3.2</td><td width="70%">Microscopic Damage in Adiabatic Shear Bands</td><td width="10%" align="right">57</td></tr><tr><td width="20%">3.3</td><td width="70%">Metallurgical Implications</td><td width="10%" align="right">69</td></tr><tr><td width="20%">3.4</td><td width="70%">Effects of Stress State</td><td width="10%" align="right">73</td></tr><tr><td width="20%">4</td><td width="70%">Testing Methods</td><td width="10%" align="right">76</td></tr><tr><td width="20%">4.1</td><td width="70%">General Requirements and Remarks</td><td width="10%" align="right">76</td></tr><tr><td width="20%">4.2</td><td width="70%">Dynamic Torsion Tests</td><td width="10%" align="right">80</td></tr><tr><td width="20%">4.3</td><td width="70%">Dynamic Compression Tests</td><td width="10%" align="right">91</td></tr><tr id="yui_3_7_3_1_1356267270901_1605"><td width="20%">4.4</td><td id="yui_3_7_3_1_1356267270901_1604" width="70%">Contained Cylinder Tests</td><td width="10%" align="right">95</td></tr><tr id="yui_3_7_3_1_1356267270901_1607"><td width="20%">4.5</td><td id="yui_3_7_3_1_1356267270901_1606" width="70%">Transient Measurements</td><td width="10%" align="right">98</td></tr><tr><td width="20%">5</td><td width="70%">Constitutive Equations</td><td width="10%" align="right">104</td></tr><tr><td width="20%">5.1</td><td width="70%">Effect of Strain Rate on Stress-Strain Behaviour</td><td width="10%" align="right">104</td></tr><tr><td width="20%">5.2</td><td width="70%">Strain-Rate History Effects</td><td width="10%" align="right">110</td></tr><tr><td width="20%">5.3</td><td width="70%">Effect of Temperature on Stress-Strain Behaviour</td><td width="10%" align="right">114</td></tr><tr id="yui_3_7_3_1_1356267270901_1609"><td width="20%">5.4</td><td id="yui_3_7_3_1_1356267270901_1608" width="70%">Constitutive Equations for Non-Metals</td><td width="10%" align="right">124</td></tr><tr id="yui_3_7_3_1_1356267270901_1611"><td width="20%">6</td><td id="yui_3_7_3_1_1356267270901_1610" width="70%">Occurrence of Adiabatic Shear Bands</td><td width="10%" align="right">125</td></tr><tr><td width="20%">6.1</td><td width="70%">Empirical Criteria</td><td width="10%" align="right">125</td></tr><tr><td width="20%">6.2</td><td width="70%">One-Dimensional Equations and Linear Instability Analysis</td><td width="10%" align="right">134</td></tr><tr><td width="20%">6.3</td><td width="70%">Localization Analysis</td><td width="10%" align="right">140</td></tr><tr><td width="20%">6.4</td><td width="70%">Experimental Verification</td><td width="10%" align="right">146</td></tr><tr><td width="20%">7</td><td width="70%">Formation and Evolution of Shear Bands</td><td width="10%" align="right">155</td></tr><tr><td width="20%">7.1</td><td width="70%">Post-Instability Phenomena</td><td width="10%" align="right">156</td></tr><tr><td width="20%">7.2</td><td width="70%">Scaling and Approximations</td><td width="10%" align="right">162</td></tr><tr><td width="20%">7.3</td><td width="70%">Wave Trapping and Viscous Dissipation</td><td width="10%" align="right">167</td></tr><tr><td width="20%">7.4</td><td width="70%">The Intermediate Stage and the Formation of Adiabatic Shear Bands</td><td width="10%" align="right">171</td></tr><tr><td width="20%">7.5</td><td width="70%">Late Stage Behaviour and Post-Mortem Morphology</td><td width="10%" align="right">179</td></tr><tr><td width="20%">7.6</td><td width="70%">Adiabatic Shear Bands in Multi-Dimensional Stress States</td><td width="10%" align="right">187</td></tr><tr><td width="20%">8</td><td width="70%">Numerical Studies of Adiabatic Shear Bands</td><td width="10%" align="right">194</td></tr><tr id="yui_3_7_3_1_1356267270901_1613"><td width="20%">8.1</td><td id="yui_3_7_3_1_1356267270901_1612" width="70%">Objects, Problems and Techniques Involved in Numerical Simulations</td><td width="10%" align="right">194</td></tr><tr><td width="20%">8.2</td><td width="70%">One-Dimensional Simulation of Adiabatic Shear Banding</td><td width="10%" align="right">199</td></tr><tr><td width="20%">8.3</td><td width="70%">Simulation with Adaptive Finite Element Methods</td><td width="10%" align="right">213</td></tr><tr><td width="20%">8.4</td><td width="70%">Adiabatic Shear Bands in the Plane Strain Stress State</td><td width="10%" align="right">218</td></tr><tr id="yui_3_7_3_1_1356267270901_1615"><td width="20%">9</td><td id="yui_3_7_3_1_1356267270901_1614" width="70%">Selected Topics in Impact Dynamics</td><td width="10%" align="right">229</td></tr><tr id="yui_3_7_3_1_1356267270901_1617"><td width="20%">9.1</td><td id="yui_3_7_3_1_1356267270901_1616" width="70%">Planar Impact</td><td width="10%" align="right">230</td></tr><tr><td width="20%">9.2</td><td width="70%">Fragmentation</td><td width="10%" align="right">237</td></tr><tr><td width="20%">9.3</td><td width="70%">Penetration</td><td width="10%" align="right">244</td></tr><tr><td width="20%">9.4</td><td width="70%">Erosion</td><td width="10%" align="right">255</td></tr><tr><td width="20%">9.5</td><td width="70%">Ignition of Explosives</td><td width="10%" align="right">261</td></tr><tr><td width="20%">9.6</td><td width="70%">Explosive Welding</td><td width="10%" align="right">268</td></tr><tr><td width="20%">10</td><td width="70%">Selected Topics in Metalworking</td><td width="10%" align="right">273</td></tr><tr><td width="20%">10.1</td><td width="70%">Classification of Processes</td><td width="10%" align="right">273</td></tr><tr><td width="20%">10.2</td><td width="70%">Upsetting</td><td width="10%" align="right">276</td></tr><tr><td width="20%">10.3</td><td width="70%">Metalcutting</td><td width="10%" align="right">286</td></tr><tr><td width="20%">10.4</td><td width="70%">Blanking</td><td width="10%" align="right">293</td></tr><tr><td width="20%">&nbsp;</td><td width="70%">Appendices</td><td width="10%" align="right">297</td></tr><tr><td width="20%">A</td><td width="70%">Quick Reference</td><td width="10%" align="right">298</td></tr><tr><td width="20%">B</td><td width="70%">Specific Heat and Thermal Conductivity</td><td width="10%" align="right">301</td></tr><tr id="yui_3_7_3_1_1356267270901_1619"><td width="20%">C</td><td id="yui_3_7_3_1_1356267270901_1618" width="70%">Thermal Softening and Related Temperature Dependence</td><td width="10%" align="right">312</td></tr><tr id="yui_3_7_3_1_1356267270901_1623"><td width="20%">D</td><td id="yui_3_7_3_1_1356267270901_1622" width="70%">Materials Showing Adiabatic Shear Bands</td><td width="10%" align="right">335</td></tr><tr id="yui_3_7_3_1_1356267270901_1628"><td width="20%">E</td><td id="yui_3_7_3_1_1356267270901_1627" width="70%">Specification of Selected Materials Showing Adiabatic Shear Bands</td><td width="10%" align="right">341</td></tr><tr id="yui_3_7_3_1_1356267270901_1630"><td width="20%">F</td><td id="yui_3_7_3_1_1356267270901_1629" width="70%">Conversion Factors</td><td width="10%" align="right">357</td></tr><tr id="yui_3_7_3_1_1356267270901_1632"><td width="20%">&nbsp;</td><td id="yui_3_7_3_1_1356267270901_1631" width="70%">References</td><td width="10%" align="right">358</td></tr><tr id="yui_3_7_3_1_1356267270901_1634"><td width="20%">&nbsp;</td><td id="yui_3_7_3_1_1356267270901_1633" width="70%">Author Index</td><td width="10%" align="right">369</td></tr><tr id="yui_3_7_3_1_1356267270901_1636"><td width="20%">&nbsp;</td><td id="yui_3_7_3_1_1356267270901_1635" width="70%">Subject Index</td><td id="yui_3_7_3_1_1356267270901_1637" width="10%" align="right">375</td></tr></tbody></table></div>

Prediction of Effective Moduli of Carbon Nanotube-Reinforced Composites with Waviness and Debonding

Carbon nanotubes (CNTs) have been regarded as ideal reinforcements of high-performance composites with enormous applications. However, the waviness of the CNTs and the interfacial bonding condition between them and the matrix are two key factors that influence the reinforcing efficiency. In this paper, the effects of the waviness of the CNTs and the interfacial debonding between them and the matrix on the effective moduli of CNT-reinforced composites are studied. A simple analytical model is presented to investigate the influence of the waviness on the effective moduli. Then, two methods are proposed to examine the influence of the debonding. It is shown that both the waviness and debonding can significantly reduce the stiffening effect of the CNTs. The effective moduli are very sensitive to the waviness when the latter is small, and this sensitivity decreases with the increase of the waviness. (C) 2008 Elsevier Ltd. All rights reserved.

Quantum Efficiency And Temperature Coefficients Of Gainp/Gaas Dual-Junction Solar Cell

GaInP/GaAs dual-junction solar cell with a conversion efficiency of 25.2% has been fabricated using metalorganic chemical vapor deposition (MOCVD) technique. Quantum efficiencies of the solar cell were measured within a temperature range from 25 to 160A degrees C. The results indicate that the quantum efficiencies of the subcells increase slightly with the increasing temperature. And red-shift phenomena of absorption limit for all subcells are observed by increasing the cell's work temperature, which are consistent with the viewpoint of energy gap narrowing effect. The short-circuit current density temperature coefficients dJ (sc)/dT of GaInP subcell and GaAs subcell are determined to be 8.9 and 7.4 mu A/cm(2)/A degrees C from the quantum efficiency data, respectively. And the open-circuit cell voltage temperature coefficients dV (oc)/dT calculated based on a theoretical equation are -2.4 mV/A degrees C and -2.1 mV/A degrees C for GaInP subcell and GaAs subcell.

A scaling law of photoionization in ultrashort pulses

By means of the numerical solution of time-dependant Schrodinger equation, we verify a scaling law of photoionization in ultrashort pulses. We find that for a given carrier-envelope phase and duration of the pulse, identical photoionizations are obtained provided that when the central frequency of the pulse is enlarged by k times, the atomic binding potential is enlarged by k times, and the laser intensity is enlarged by k(3) times. The scaling law allows us to reach a significant control over direction of photoemission and offers exciting prospects of reaching similar physical processes in different interacting systems which constitutes a novel kind of coherent control.

Carrier-envelope phase control of carrier-wave Rabi flopping in asymmetric semiparabolic quantum well

We investigate the carrier-wave Rabi flopping effects in an asymmetric semiparabolic semiconductor quantum well (QW) with few-cycle pulse. It is found that higher spectral components of few-cycle ultrashort pulses in the semiparabolic QW depend crucially on the carrier-envelope phase (CEP) of the few-cycle ultrashort pulses: continuum and distinct peaks can be achieved by controlling the CEP. Our results demonstrate that by adjusting the CEP of few-cycle ultrashort pulses, the intersubband dynamics in the asymmetric semiparabolic QW can be controlled in an ultrashort timescale with moderate laser intensity. (c) 2008 Optical Society of America.

Duration-dependent asymmetry in photoionization of H atoms in few-cycle laser pulses

The photoionization of H atoms irradiated by few-cycle laser pulses is studied numerically. The variations of the total ionization, the partial ionizations in opposite directions, and the corresponding asymmetry with the carrier-envelope phase in several pulse durations are obtained. We find that besides a stronger modulation on the partial ionizations, the change of pulse duration leads to a shift along carrier-envelope (CE) phase in the calculated signals. The phase shift arises from the nonlinear property of ionization and relates closely to the Coulomb attraction of the parent ion to the ionized electron. Our calculations show good agreement with the experimental observation under similar conditions.

Optical solitons in a four-level inverted-Y system

With one weak probe field and two strong pumping fields, the possibility of producing superluminal optical solitons is discussed in a lifetime-broadened inverted-Y atomic medium with proper parameters. As the group velocity of the solitons is larger than c, its occurrence can be controlled by modulating the intensities and the detunings of lasers.

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Routing scheme, permutation properties, and optical implementation of a four-shuffle-exchange-based Omega network

The routing scheme and some permutation properties of a four-shuffle-exchange-based Omega network are discussed. The corresponding optical setup, which is composed of 2-D phase spatial light modulators and calcite plates, is proposed and demonstrated through mapping the inputs to a 2-D array. Instead of one shuffle-exchange followed by one switching operation as in ordinary Omega networks, in our presented system, the shuffle interconnection embraced in the switches is accomplished simply by varying the switching structure of each stage. For the proposed polarization-optical modules, the system is compact in structure, efficient in performance, and insensitive to the environment. (C) 1997 Society of Photo-Optical Instrumentation Engineers.

Frequency upconversion properties of Er3+/Yb3+-codoped lead-germanium-bismuth oxide glasses

The frequency upconversion properties of Er3+/Yb3+-codoped heavy metal oxide lead-germanium-bismuth oxide glasses under 975 mn excitation are investigated. Intense green and red emission bands centered at 536, 556 and 672 run, corresponding to the H-2(1/2) --> I-4(15/2), S-4(3/2) --> I-4(15/2) and F-4(9/2) -->I-4(15/2) transitions of Er3+, respectively, were simultaneously observed at room temperature. The influences of PbO on upconversion intensity for the green (536 and 556 nm) and red (672 nm) emissions were compared and discussed. The optimized rare earth doping ratio of Er3+ and Yb3+, is 1:5 for these glasses, which results in the stronger upconversion fluorescence intensities. The dependence of intensities of upconversion emission on excitation power and possible upconversion mechanisms were evaluated and analyzed. The structure of glass has been investigated by means of infrared (IR) spectral analysis. The results indicate that the Er3+/Yb3+-codoped heavy metal oxide lead-germanium-bismuth oxide glasses may be a potential materials for developing upconversion fiber optic devices. (C) 2006 Published by Elsevier Ltd.

Influences of phase shift on superresolution performances of annular filters

This paper investigates the influences of phase shift on superresolution performances of annular filters. Firstly, it investigates the influence of phase shift on axial superresolution. It proves theoretically that axial superresolution can not be obtained by two-zone phase filter with phase shift pi, and it gets the phase shift with which axial superresolution can be brought by two-zone phase filter. Secondly, it studies the influence of phase shift on transverse superresolution. It finds that the three-zone phase filter with arbitrary phase shift has an almost equal optimal transverse gain to that of commonly used three-zone phase filter, but can produce a much higher axial superresolution gain. Thirdly, it investigates the influence of phase shift on three-dimensional superresolution. Three-dimensional superresolution capability and design margin of three-zone complex filter with arbitrary phase shift are obtained, which presents the theoretical basis for three-dimensional superresolution design. Finally, it investigates the influence of phase shift on focal shift. To obtain desired focal shifts, it designs a series of three-zone phase filters with different phase shifts. A spatial light modulator (SLM) is used to implement the designed filters. By regulating the voltage imposed on the SLM, an accurate focal shift control is obtained.

Design and application of three-zone annular filters

We design three-zone annular filters to be applied to optical storage system. The designed filters extend the depth of focus and realize transverse superresolution simultaneously, which will improve the performance of optical storage system greatly. And we propose two feasible schemes to improve imaging resolution of three-dimensional imaging system. One scheme depends on a complex filter formed by cascading of a three-zone phase filter and a three-zone amplitude filter. The complex filter converge the optimized transverse superresolution and the optimized axial superresolution of two different filters onto a single filter. It can improve the three-dimensional imaging performances greatly. Another scheme depends on a single three-zone complex filter. We propose a three-zone complex filter with phase shift 0.8 pi, which presents bigger design margin, better imaging quality and stronger three-dimensional superresolution capability. (c) 2006 Elsevier GmbH. All rights reserved.