SpringerLink Springer Engineering eBooks 2017 English+International

Preface; Contents; Abbreviations; Nomenclature; 1 The Generation of Elastic Acoustic Emission Waves Due to the Fracture of Solids; 1.1 Some Fracture Mechanics Criteria Under Quasi-Static Loading of Materials; 1.1.1 Energy Criteria; 1.1.2 Force Criteria; 1.1.3 Deformation Criteria; 1.2 Micro-Cracking of Solids; 1.3 Physical Grounds of AE Generation; 1.4 Basic Parameters of the AE Signals; 1.4.1 Cumulative Count [60]; 1.4.2 AE Count Rate [60]; 1.4.3 Amplitude Distribution of AES; 1.4.4 Spectral and Energy Distribution of AES; 1.4.5 Identification of AES by the Waveform Type.

1.5 Basic Analytical Dependences Between the Fracture Parameters and the AE SignalsReferences; 2 Propagation of Elastic Waves in Solids; 2.1 Types of Elastic Waves; 2.1.1 Some General Ideas on Elastic Strain; 2.1.2 A Wave Equation for a Solid; 2.1.3 Main Ideas of the Wave Process; 2.1.4 Spatial Elastic Waves; 2.1.5 Rayleigh Surface Wave; 2.1.6 Head (Creeping) Wave; 2.1.7 Waves at an Interface of Two Media; 2.1.8 Waves in Layers and Plates; 2.1.9 Waves in Bars; 2.1.10 Other Types of Waves; 2.2 Some Basic Acoustic Properties of Media; 2.2.1 Impedance and Wave Resistance of a Medium.

2.2.2 Decay of Elastic Waves2.2.3 Diffraction of Elastic Waves; 2.2.4 Refraction of Elastic Waves; 2.3 AE Sources; References; 3 Analysis of Acoustic Emission Caused by Internal Cracks; 3.1 Nucleation and Sub-critical CRACK Growth; 3.1.1 Nucleation of a Mode I Penny-Shaped Crack; 3.1.2 Nucleation of a Mode III Penny-Shaped Crack; 3.2 Modelling the Sub-critical Crack Growth at Local Areas of Its Contour as a Source of Acoustic Emission Signals; 3.3 The Effect of Body Boundaries on AE Signals Caused by the Growth of an Internal Defect.

3.4 The Waveguide Effect on the Change of the Parameters of AE Signals3.5 The Assessment of Surface Displacements Caused by an Internal AE Source; References; 4 Some Methodological Foundations for Selecting and Processing AE Signals; 4.1 Some General Methodical Guidelines on the Use of the AE Method in the Mechanical Testing of Materials with Cracks; 4.2 Technical Aspects of Preparation for AE Tests; 4.3 Selection of Informative Parameters of AE Signals; 4.4 Simulation of AE Sources; 4.5 Simulation of AE Events at the AET Output; 4.6 Spectrum of the AE Signals During Macro-crack Growth.

4.7 Directional Diagram of AE Radiation During Macro-crack Growth4.8 Estimation of AE Signals Caused by Propagation of Internal Crack-like Defects; 4.9 Methods of the AET Mounting at IO; 4.10 Selection of Useful AES During AE Tests; 4.10.1 Selection of a Working Frequency Band of AE Facilities; 4.10.2 Filtration of AES by Instrumental Facilities; 4.10.3 Application of the "Dead Time" Mode; 4.10.4 The Kaiser Effect Application; 4.10.5 A Method of Spatial Selection of AES; 4.10.6 Other Methodical Approaches; References.

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.