Adiabatic shear localization: occurrence, theories, and applications

IMECH-IR > 力学所知识产出(1956-2008)

Adiabatic shear localization: occurrence, theories, and applications

Bai YL(白以龙)

; Dodd B

出版地

Oxford

出版者

Pergamon Press

1992

摘要

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.

1	Introduction	1
1.1	What is an Adiabatic Shear Band?	1
1.2	The Importance of Adiabatic Shear Bands	6
1.3	Where Adiabatic Shear Bands Occur	10
1.4	Historical Aspects of Shear Bands	11
1.5	Adiabatic Shear Bands and Fracture Maps	14
1.6	Scope of the Book	20
2	Characteristic Aspects of Adiabatic Shear Bands	24
2.1	General Features	24
2.2	Deformed Bands	27
2.3	Transformed Bands	28
2.4	Variables Relevant to Adiabatic Shear Banding	35
2.5	Adiabatic Shear Bands in Non-Metals	44
3	Fracture and Damage Related to Adiabatic Shear Bands	54
3.1	Adiabatic Shear Band Induced Fracture	54
3.2	Microscopic Damage in Adiabatic Shear Bands	57
3.3	Metallurgical Implications	69
3.4	Effects of Stress State	73
4	Testing Methods	76
4.1	General Requirements and Remarks	76
4.2	Dynamic Torsion Tests	80
4.3	Dynamic Compression Tests	91
4.4	Contained Cylinder Tests	95
4.5	Transient Measurements	98
5	Constitutive Equations	104
5.1	Effect of Strain Rate on Stress-Strain Behaviour	104
5.2	Strain-Rate History Effects	110
5.3	Effect of Temperature on Stress-Strain Behaviour	114
5.4	Constitutive Equations for Non-Metals	124
6	Occurrence of Adiabatic Shear Bands	125
6.1	Empirical Criteria	125
6.2	One-Dimensional Equations and Linear Instability Analysis	134
6.3	Localization Analysis	140
6.4	Experimental Verification	146
7	Formation and Evolution of Shear Bands	155
7.1	Post-Instability Phenomena	156
7.2	Scaling and Approximations	162
7.3	Wave Trapping and Viscous Dissipation	167
7.4	The Intermediate Stage and the Formation of Adiabatic Shear Bands	171
7.5	Late Stage Behaviour and Post-Mortem Morphology	179
7.6	Adiabatic Shear Bands in Multi-Dimensional Stress States	187
8	Numerical Studies of Adiabatic Shear Bands	194
8.1	Objects, Problems and Techniques Involved in Numerical Simulations	194
8.2	One-Dimensional Simulation of Adiabatic Shear Banding	199
8.3	Simulation with Adaptive Finite Element Methods	213
8.4	Adiabatic Shear Bands in the Plane Strain Stress State	218
9	Selected Topics in Impact Dynamics	229
9.1	Planar Impact	230
9.2	Fragmentation	237
9.3	Penetration	244
9.4	Erosion	255
9.5	Ignition of Explosives	261
9.6	Explosive Welding	268
10	Selected Topics in Metalworking	273
10.1	Classification of Processes	273
10.2	Upsetting	276
10.3	Metalcutting	286
10.4	Blanking	293
	Appendices	297
A	Quick Reference	298
B	Specific Heat and Thermal Conductivity	301
C	Thermal Softening and Related Temperature Dependence	312
D	Materials Showing Adiabatic Shear Bands	335
E	Specification of Selected Materials Showing Adiabatic Shear Bands	341
F	Conversion Factors	357
	References	358
	Author Index	369
	Subject Index	375