Mechanical Testing of Materials

Preface
Contents
About the Authors
1 Tensile Testing
	1.1 Specimens and Testing
	1.2 Stress and Strain
	1.3 Engineering Stress–Strain Curves
	1.4 Yield Point
	1.5 Strain Hardening
	1.6 Hysteresis Loop in Plastic Deformation
	1.7 Bauschinger Effect
	1.8 True Stress–True Strain Curve
	1.9 Stress State in the Neck Area
	1.10 Approximate McGregor Method for Determining the Stress–Strain Curve
	1.11 Idealized Stress–Strain Curves
	1.12 Analytical Expression of Stress–Strain Curves
	1.13 Ductility
	1.14 Resilience
	1.15 Tensile Toughness
	1.16 Poisson’s Ratio
	1.17 Bulk Modulus
	1.18 Standards
	1.19 Material Properties
	Further Readings
2 Compression, Bending, Torsion and Multiaxial Testing
	2.1 Compression Test
		2.1.1 Specimens
		2.1.2 Stress–Strain Curve
		2.1.3 Comparison of Stress–Strain Curves in Compression and Tension
	2.2 Bending Test
	2.3 Torsion Test
	2.4 Multiaxial Testing
		2.4.1 Introduction
		2.4.2 Biaxial Tension Test
		2.4.3 Biaxial Tension/Compression Strip Test
		2.4.4 Tube Test
		2.4.5 Spherical Vessel Test
		2.4.6 Combined Tension/Compression–Torsion Ring Test
		2.4.7 Combined Tension/Compression–Torsion Tube Test
		2.4.8 Combined Tension/Compression–Torsion–Internal Pressure Tube Test
		2.4.9 Failure Criteria
	2.5 ASTM Standards
	Further Readings
3 Indentation Testing
	3.1 Introduction
	3.2 Contact Mechanics
	3.3 Macroindentation Testing
		3.3.1 Brinell Test
		3.3.2 Meyer Test
		3.3.3 Vickers Test
		3.3.4 Rockwell Test
	3.4 Microindentation Testing
		3.4.1 Vickers Test
		3.4.2 Knoop Test
	3.5 Nanoindentation Testing
		3.5.1 Introduction
		3.5.2 The Elastic Contact Method
		3.5.3 Nanoindentation for Measuring Fracture Toughness
		3.5.4 Nanoindentation for Measuring Interfacial Fracture Toughness—Conical Indenters
		3.5.5 Nanoindentation for Measuring Interfacial Fracture Toughness—Wedge Indenters
	3.6 ASTM Standards
	Further Readings
4 Fracture Mechanics Testing
	4.1 Critical Stress Intensity Factor Fracture Criterion
		4.1.1 The Linear Elastic Stress Field
		4.1.2 Strain Energy Release Rate
		4.1.3 Fracture Criterion
		4.1.4 Variation of Kc with Specimen Thickness
		4.1.5 Experimental Determination of KIc
	4.2 J-Integral Fracture Criterion
		4.2.1 J-Integral
		4.2.2 J-Integral Fracture Criterion
		4.2.3 Experimental Determination of J-Integral
	4.3 Crack Opening Displacement Fracture Criterion
		4.3.1 Introduction
		4.3.2 COD Design Curve
		4.3.3 Standard COD Test
	4.4 Strain Energy Density Failure Criterion
		4.4.1 Introduction
		4.4.2 Volume Strain Energy Density
		4.4.3 Basic Hypotheses
		4.4.4 Two-Dimensional Linear Elastic Crack Problems
		4.4.5 Critical Strain Energy Density Factor Sc
	4.5 Dynamic Problems
	4.6 ASTM Standards
	Further Readings
5 Fatigue and Environment-Assisted Testing
	5.1 Introduction
	5.2 Fatigue Study Based on Stress
		5.2.1 Basic Definitions
		5.2.2 Stress Versus Life (S–N) Curves
		5.2.3 The Effect of Mean Stress
		5.2.4 Multiaxial Stresses
		5.2.5 Variable Amplitude Loads
	5.3 Fatigue Study Based on Fracture Mechanics
		5.3.1 General Considerations
		5.3.2 Crack Propagation Laws
		5.3.3 Fatigue Life Calculations
	5.4 Variable Amplitude Loading
		5.4.1 Introduction
		5.4.2 Overload Effect
		5.4.3 Life Estimate Based on Summation of Crack Increments
		5.4.4 Models for Predicting Fatigue Life
		5.4.5 Miner Rule
	5.5 Fatigue Testing
		5.5.1 Introduction
		5.5.2 Uncracked Specimens
		5.5.3 Cracked Specimens
	5.6 Environment-Assisted Fracture
		5.6.1 Introduction
		5.6.2 Time-To-Failure Tests
		5.6.3 Growth Rate Tests
		5.6.4 Life Estimate
	5.7 ASTM Standards
	Further Readings
6 Creep Testing
	6.1 Mechanical Behavior of Materials
	6.2 Rheological Models
	6.3 Creep Deformation
		6.3.1 Steady-State Creep
		6.3.2 Transient Creep
		6.3.3 Relaxation Behavior
	6.4 Linear Viscoelasticity
	6.5 Nonlinear Creep
	6.6 Nonlinear Stress Relaxation
	6.7 Stress–Strain Relationships in Three Dimensions
	6.8 Solution of Creep Problems
	6.9 Creep and Relaxation Testing
	6.10 ASTM Standards
	Further Readings
7 Testing at High Strain Rates
	7.1 Introduction
	7.2 Strain Rate
	7.3 Tests at Different Strain Rates
	7.4 High-Speed Load Frames
	7.5 Drop Weight Impact Test
		7.5.1 Introduction
		7.5.2 Experimental Procedure and Instrumentation
		7.5.3 Data Analysis
		7.5.4 Discussion
	7.6 Pendulum Impact Test
		7.6.1 Introduction
		7.6.2 Experimental Arrangement
		7.6.3 Energy Considerations
		7.6.4 Charpy Impact Test
		7.6.5 Izod Impact Test
		7.6.6 Discussion
	7.7 Split-Hopkinson (Kolsky) Bar Impact Test
		7.7.1 Introduction
		7.7.2 Experimental Arrangement
		7.7.3 Impact Stress Waves in the Bars
		7.7.4 Analysis of Experimental Data
		7.7.5 Modifications of SHPB Arrangement for Ceramics and Soft Materials
		7.7.6 Split-Hopkinson Tension Bar
		7.7.7 Split-Hopkinson Torsion Bar
	7.8 Taylor Impact Test
		7.8.1 Introduction
		7.8.2 Experimental Arrangement
		7.8.3 Specimen and Test Procedure
		7.8.4 Determination of the Yield Stress
	7.9 Expanding Ring Test
		7.9.1 Introduction
		7.9.2 Experimental Arrangement
		7.9.3 Mathematical Analysis
		7.9.4 Discussion
	7.10 Plate Impact Test
		7.10.1 Introduction
		7.10.2 Experimental Arrangement
		7.10.3 Rankine–Hugoniot Curve
	7.11 Optical Methods
	7.12 ASTM Standards
	Further Readings
8 Nondestructive Testing (NDT)
	8.1 Introduction
	8.2 Dye Penetrant Testing (PT)
		8.2.1 Principle
		8.2.2 Application
		8.2.3 Discussion
	8.3 Magnetic Particle Testing (MT)
		8.3.1 Introduction
		8.3.2 Detection of Discontinuities
		8.3.3 Discussion
	8.4 Eddy Current Testing (ECT)
		8.4.1 Theory and Principle
		8.4.2 Application
		8.4.3 Discussion
	8.5 X-ray Diffraction Testing
		8.5.1 Introduction
		8.5.2 X-rays
		8.5.3 X-ray Diffraction
		8.5.4 Measurement of Strain
		8.5.5 Instrumentation
		8.5.6 Discussion
	8.6 Ultrasonic Testing (UT)
		8.6.1 Introduction
		8.6.2 Operation
		8.6.3 Discussion
	8.7 Acoustic Emission Testing (AET)
		8.7.1 Introduction
		8.7.2 Sources of Acoustic Emission
		8.7.3 Propagation of AE Signals
		8.7.4 Testing
		8.7.5 Source Location
		8.7.6 Discussion
	8.8 ASTM Standards
	Further Readings
9 Testing of Concrete
	9.1 Introduction
	9.2 Compression Test
		9.2.1 Introduction
		9.2.2 Compression Stress
		9.2.3 Specimens
		9.2.4 Stress–Strain Curve
		9.2.5 Failure Mechanisms
		9.2.6 Effect of Specimen Ends
		9.2.7 Size Effect on Strength of Cylinders
		9.2.8 Comparison of Strength of Cubes and Cylinders
	9.3 Tension Test
		9.3.1 Introduction
		9.3.2 Direct Tension Test
		9.3.3 Brazilian (Splitting) Test
		9.3.4 Flexure Test
		9.3.5 The Ring Test
	9.4 Fracture Mechanics of Concrete
		9.4.1 Introduction
		9.4.2 Why Fracture Mechanics of Concrete?
		9.4.3 Tensile Behavior of Concrete
		9.4.4 The Fracture Process Zone
		9.4.5 Fracture Mechanics
		9.4.6 Cohesive Crack Models
		9.4.7 Experimental Determination of GIc
	9.5 Size Effect
	9.6 ASTM Standards
	Further Readings
10 Testing of Composites
	10.1 Introduction
	10.2 Fiber Reinforced Composites
	10.3 Tension Testing
		10.3.1 Introduction
		10.3.2 Specimens
		10.3.3 Experimental
		10.3.4 Data Reduction
	10.4 Compression Testing
		10.4.1 Introduction
		10.4.2 Shear Loading Methods
		10.4.3 End Loading Methods
		10.4.4 Sandwich Methods
		10.4.5 Data Reduction
	10.5 Shear Testing
		10.5.1 Introduction
		10.5.2 Rail Method
		10.5.3 Tensile Methods
		10.5.4 Iosipescu and Arcan Methods
	10.6 Interlaminar Shear Strength
	10.7 Interlaminar Fracture Toughness
		10.7.1 Introduction
		10.7.2 Mode-I Delamination
		10.7.3 Mode-II Delamination
		10.7.4 Mixed-Mode-I/II Delamination
		10.7.5 Mode-III Delamination
	10.8 Sandwich Materials
		10.8.1 Introduction
		10.8.2 Failure Modes
	10.9 ASTM Standards
		10.9.1 ASTM Standards for Fiber Composites
		10.9.2 ASTM Standards for Sandwich Materials
	Further Readings
Index