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EB

EB

ONLINE

Cham : Springer International Publishing : Imprint: Springer, 2017

1 online zdroj

ISBN 978-3-319-49350-3 (e-kniha)

ISBN 9783319493480 (print)

Foundations of Engineering Mechanics, ISSN 1612-1384

Printed edition: ISBN 9783319493480

This monograph analyses in detail the physical aspects of the elastic waves radiation during deformation or fracture of materials. I presents the  methodological bases for the practical use of acoustic emission device, and describes the results of theoretical and experimental researches of evaluation of the crack growth resistance of materials, selection of the useful AE signals. The efficiency of this methodology is shown through the diagnostics of various-purpose industrial objects. The authors obtain results of experimental researches with the help of the new methods and facilities..

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1 The Generation of Elastic Acoustic Emission Waves Due to the Fracture of Solids 1 // 1.1 Some Fracture Mechanics Criteria Under Quasi-Static Loading of Materials 1 // 1.1.1 Energy Criteria 4 // 1.1.2 Force Criteria 7 // 1.1.3 Deformation Criteria 11 // 1.2 Micro-Cracking of Solids 13 // 1.3 Physical Grounds of AE Generation 14 // 1.4 Basic Parameters of the AE Signals 17 // 1.4.1 Cumulative Count [60] 18 // 1.4.2 AE Count Rate [60] 18 // 1.4.3 Amplitude Distribution of AES 19 // 1.4.4 Spectral and Energy Distribution of AES 19 // 1.4.5 Identification of AES by the Waveform Type 20 // 1.5 Basic Analytical Dependences Between the Fracture Parameters and the AE Signals 20 // References 23 // 2 Propagation of Elastic Waves in Solids 29 // 2.1 Types of Elastic Waves 29 // 2.1.1 Some General Ideas on Elastic Strain 29 // 2.1.2 A Wave Equation for a Solid 31 // 2.1.3 Main Ideas of the Wave Process 32 // 2.1.4 Spatial Elastic Waves 35 // 2.1.5 Rayleigh Surface Wave 38 // 2.1.6 Head (Creeping) Wave 40 // 2.1.7 Waves at an Interface of Two Media 41 // 2.1.8 Waves in Layers and Plates 42 // 2.1.9 Waves in Bars 46 // 2.1.10 Other Types of Waves 47 // 2.2 Some Basic Acoustic Properties of Media 50 // 2.2.1 Impedance and Wave Resistance of a Medium 50 // 2.2.2 Decay of Elastic Waves 51 // 2.2.3 Diffraction of Elastic Waves 56 // 2.2.4 Refraction of Elastic Waves 61 // 2.3 AE Sources 61 // References 69 // 3 Analysis of Acoustic Emission Caused by Internal Cracks 75 // 3.1 Nucleation and Sub-critical CRACK Growth 76 // 3.1.1 Nucleation of a Mode I Penny-Shaped Crack 76 // 3.1.2 Nucleation of a Mode ID Penny-Shaped Crack 83 // 3.2 Modelling the Sub-critical Crack Growth at Local Areas of Its Contour as a Source of Acoustic Emission Signals 88 // 3.3 The Effect of Body Boundaries on AE Signals Caused by the Growth of an Internal Defect 91 //

3.4 The Waveguide Effect on the Change of the Parameters of AE Signals 95 // 3.5 The Assessment of Surface Displacements Caused by an Internal AE Source 98 // References 103 // 4 Some Methodological Foundations for Selecting and Processing AE Signals 107 // 4.1 Some General Methodical Guidelines on the Use of the AE Method in the Mechanical Testing of Materials with Cracks 107 // 4.2 Technical Aspects of Preparation for AE Tests 111 // 4.3 Selection of Informative Parameters of AE Signals 113 // 4.4 Simulation of AE Sources 114 // 4.5 Simulation of AE Events at the AET Output 120 // 4.6 Spectrum of the AE Signals During Macro-crack Growth 124 // 4.7 Directional Diagram of AE Radiation During Macro-crack // Growth 130 // 4.8 Estimation of AE Signals Caused by Propagation of Internal Crack-like Defects 134 // 4.9 Methods of the AET Mounting at IO 139 // 4.10 Selection of Useful AES During AE Tests 141 // 4.10.1 Selection of a Working Frequency Band of AE Facilities 142 // 4.10.2 Filtration of AES by Instrumental Facilities 148 // 4.10.3 Application of the “Dead Time” Mode 148 // 4.10.4 The Kaiser Effect Application 150 // 4.10.5 A Method of Spatial Selection of AES 151 // 4.10.6 Other Methodical Approaches 153 // References 154 // 5 Evaluation of Mechanical Characteristics and Static Crack // Growth Resistance of Materials with the Use of Aes 161 // 5.1 Identification of the AES Generated During Plastic Zone Growth 161 // 5.2 A Method for Evaluating a Macro-Crack Start 165 // 5.3 AE Estimation of the Stages of Sub-Critical Crack Propagation 171 // 5.3.1 Types of Specimens and Modes of AE Signals // Selection 171 // 5.3.2 Interpretation of Investigation Results 174 // 5.4 Estimation of a Macro-Crack Length Increment and SIE // Increase Under Static Loading 178 // 5.4.1 Some Theoretical Bases for AE Estimation of Macro-Crack Propagation Parameters 178 //

5.4.2 Test Results 180 // 5.5 AE Estimation of Strength Characteristics of Structural Materials 185 // 5.5.1 Investigation of Concrete Hardening by AE Signals // 5.5.2 AE Estimation of AES Amplitudes at a Fracture of Concrete in the Bridge Structure 194 // 5.5.3 AE Estimation of Mechanical Characteristics of Steels 201 // 5.5.4 AES Generation Under Reinforced Concrete Beam Bending 207 // References 211 // 6 Some Aspects of Applying the Acoustic Emission Method 219 // 6.1 Specific Features of Long-Term AE Testing of Industrial Objects 220 // 6.1.1 Selection of a Frequency Band and AET Placing 220 // 6.1.2 Calibration of an AE Testing System 222 // 6.1.3 Analysis and Presentation of AE Test Results 222 // 6.1.4 Stability of AE Parameters 223 // 6.1.5 Classification of AE Sources by Their Activity 228 // 6.2 Using the AE Methods for Testing the Offshore Platforms 233 // 6.3 Using the AE for Testing the Nuclear Reactors 236 // 6.4 Application of AE Method for Estimation of Strength // of Pressure Vessels and Pipelines 240 // 6.5 AE Inspection of Welded Joints 243 // 6.5.1 Verification of Selection of Materials, the Type // of Specimens, and an Investigation Method [21] 245 // 6.5.2 Results of the AE Research of the Welded Joints // and Their Interpretation 247 // 6.6 Selective On-Line AE Hydraulic Testing of an Oil Storage // Reservoir 255 // 6.6.1 Some Methodological Features of AE Testing of a // Reservoir 256 // 6.6.2 Criteria for Classifying AE Sources 259 // 6.6.3 Results of the AE Testing and Their Interpretation 262 // 6.7 AE Testing and Diagnostics of Building Structures 264 // 6.8 The AE Inspection of Bridges in Ukraine 267 // 6.9 Prospects for Further AE Application 276 // References 278