Fracture Mechanics: The Experimental Method of Caustics and the Det.-Criterion of Fracture

ISBN-13: 9781447119944 / Angielski / Miękka / 2012 / 285 str.

George A. Papadopoulos

Opis

Fracture and Mechanics is concerned with the experimental method of static and dynamic caustics and the Distribution of Determinant (Det.)-criterion of fracture. The Det.-criterion determines the conditions causing a crack and gives information on the expected angle of crack propagation. The object of this publication is to present the latest results to the re.earch and development community and to assist the teaching of experimental fracture mechanics and stress analysis in undergraduate and postgraduate courses. After discussing the basic theoretical considerations on the subject, experimental techniques and applications are introduced. Most of the results presented are based on the author's own investigations in the field of experimental mechanics since 1973 at the National Technical University of Athens.

Spis treści

I The Experimental Method of Caustics.- 1 Theory of Cracks.- 1.1 General Aspects.- 1.2 Physical Law.- 1.3 Plane-Stress Deformation.- 1.4 Plane-Strain Deformation.- 1.5 Generalized Plane-Stress Deformation.- 1.6 Complex-Stress Function.- 1.7 Westergaard Stress Function.- 1.8 Modes of Deformation.- 2 The Optical Method of Static Caustics.- 2.1 General Aspects.- 2.2 The Stress-Optical Law.- 2.3 Theory of Caustics.- 2.4 Application of the Method of Caustics in Plane Crack Problems.- 2.4.1 For Optically Isotropic Materials.- 2.4.2 For Optically Anisotropic Materials.- 2.5 Application of the Method of Caustics in Mixed-Mode Plane Crack Problems.- 2.5.1 The Stress Field at the Crack Tip for Mixed-Mode Deformation.- 2.5.2 Parametric Equations of Caustics for Biaxial Loading.- 2.5.3 Experimental Evaluation of the Biaxiality Factor k.- 2.6 Experimental Determination of the Stress-Optical Constants.- 2.7 Influence of Geometry of Edge-Cracked Plates on Stress Intensity Factors.- 2.8 Analysis of Elastic-Plastic Caustics.- 2.9 Equations of Caustics at V-Notch Tip.- 2.10 Influence of Stress-Assisted Diffusion on the Caustics.- 2.11 Study of Stress-Corrosion Crack Growth in Aluminium Alloys by Caustics.- 2.12 Influence of Orthotropy of Ductile Materials on the Caustics.- 3 The Optical Method of Dynamic Caustics.- 3.1 General Aspects.- 3.2 Dynamic Stress Field Around the Crack Tip.- 3.3 Parametric Equations of the Caustics.- 3.4 Dynamic Stress Intensity Factors $$K_I^d $$ and $$K_II^d $$.- 3.5 Application of Caustics in Dynamic Problems.- 3.5.1 Mode-I Dynamic Crack Propagation.- 3.5.2 Crack Propagation Model.- 3.6 Crack Propagation in Composite Materials.- 3.6.1 Particulate Composites.- 3.6.2 Rubber-Modified PMMA Models.- 3.6.3 PCBA-PMMA Sandwich Plates.- 3.7 Crack Propagation in Polystyrene.- 3.8 Crack Propagation Under Impact Bending Load.- 3.9 Fracture Behaviour Under Stress Pulse.- 3.9.1 Dynamic Behaviour of an Oblique Edge-Crack Under Stress Pulse.- 3.9.2 Dynamic Behaviour of a Sharp V-Notch Under Stress Pulse.- II The Det.-Criterion of Fracture.- 4 The Elastic Strain Energy Density.- 4.1 General Aspects.- 4.2 The Elastic Strain Energy.- 4.2.1 Evaluation of the Elastic Strain Energy Density from the Diameters of the Caustic.- 4.3 S2-Criterion of Fracture.- 5 Det.-Criterion of Fracture.- 5.1 General Aspects.- 5.2 Theoretical Consideration.- 5.2.1 Three-dimensional Crack Problems.- 5.2.2 Two-dimensional Crack Problems.- 6 Application of the Det.-Criterion in Plane Crack Problems.- 6.1 Cracked Plates Under Uniaxial Tension.- 6.1.1 For Singular Solution.- 6.1.2 For Solution with Constant Term.- 6.2 Cracked Plates Under Biaxial Loading.- 6.3 Cracked Plates Under Biaxial Loading With Higher-Order Approximation Solution.- 6.4 Blunt-Notched Plates Under Biaxial Loading.- 6.5 Edge-Cracked Plates Under Uniaxial Tension.- 6.5.1 For Singular Solution.- 6.5.2 For Solution with Constant Term.- 6.6 Edge Blunt-Notched Plates Under Uniaxial Tension.- 6.7 Cracked Plates Under Stress-Assisted Diffusion.- 6.7.1 For Singular Solution.- 6.7.2 For Solution with Constant Term.- 6.8 Dynamic Crack Bifurcation.- 7 Experimental Det.-Criterion of Fracture.- 7.1 The Maximum Shear Stress. Isochromatic and Isopachic Fringe Patterns.- 7.2 Experimental Method.- References.