ADVANCES IN FRACTURE RESEARCH
CONTENTS CHAPTER 1: COMPRESSIVE STRENGTH OF LAMINATED COMPOSITES: ON APPLICATION OF THE CONTINUUM FRACTURE THEORY 1 INTRODUCTION 2 THE MODEL OF A PIECEWISE-HOMOGENEOUS MEDIUM 2 1 “EXACT APPROACH AND APPROPRIATE MODELS 2 2 PROBLEM STATEMENT FOR INCOMPRESSIBLE COMPOSITES UNDERGOING LARGE DEFORMATIONS 2 3 CHARACTERISTICS DETERMINANTS 3 ASYMPTOTIC ANALYSIS 3 1 THE LONG-WAVE APPROXIMATIONS (TRANSITION TO THE CONTINUUM THEORY) 3 2 ANALYSIS OF THE EQUATIONS FOR DIFFERENT MODES OF STABILITY LOSS 4 ACCURACY OF THE CONTINUUM THEORY FOR HYPERELASTIC NON-LINEAR MATERIALS WITH A NEO-HOOKEAN POTENTIAL 4 1 TRELOAR’S POTENTIAL 4 2 RESULTS AND DISCUSSION 5 CONCLUSIONS CHAPTER 2: MACROSCOPIC CRACK PROPAGATION DUE TO STRESS-CORROSION CRACKING IN UNIDIRECTIONAL GRP COMPOSITES: MICROMECHANICAL THEORY AND ITS APPLICATION 1 INTRODUCTION 2 MICROMECHANICAL THEORY OF MACROSCOPIC CRACK PROPAGATION DUE TO STRESS-CORROSION CRACKING 3 DISCUSSION 3 1 VERIFICATION BY EXPERIMENT 3 2 MACROSCOPIC CRACK PROPAGATION RATE FOR THE LIMITING VALUES OF ?0 3 3 POWER AND COEFFICIENT OF RATE IN SIMPLE POWER LAW [34, 35] 3 4 MACROSCOPIC CRACK PROPAGATION RATE IN ALIGNED SHORT GFRP COMPOSITES 3 5 EFFECT OF MATRIX BRIDGING ON MACROSCOPIC CRACK PROPAGATION RATE 4 APPLICATION TO ESTIMATING FAILURE TIMES OF GFRP COMPOSITE STRUCTURES 4 1 UNIDIRECTIONAL GFRP COMPOSITE PLATES 4 2 (0/90)N CROSS-PLY GFRP COMPOSITE LAMINATES CHAPTER 3: DAMAGE MECHANISMS IN PULTRUDED UNIDIRECTIONAL FIBER REINFORCED COMPOSITES UNDER STATIC AND FATIGUE LOADS 1 INTRODUCTION 1 1 REINFORCEMENT MATERIAL SUPPLY 1 2 DIE 1 3 THE PULLING MECHANISM 2 MECHANICAL CHARACTERISTICS 2 1 MATERIAL 2 2 STATIC MECHANICAL CHARACTERISTICS 3 EXPERIMENTAL TESTS 3 1 TENSILE TESTS 3 2 COMPRESSION TESTS 4 MICROSCOPIC EXAMINATION 4 1 MICROSCOPIC EXAMINATION IN THE MATERIAL NOT LOADED 4 2 BLACK SPECIMENS 4 3 COMPRESSION TESTS 5 FATIGUE TESTS 5 1 EFFECT OF THE STRESS RATIO AND OF THE GRIPPING CONDITIONS 5 2 EFFECT OF TEMPERATURE AND FREQUENCY 6 FATIGUE DAMAGE 6 1 STIFFNESS MEASUREMENTS 6 2 MICROSCOPICAL DAMAGE 7 CONCLUSIONS CHAPTER 4: FATIGUE DAMAGE OF PARTICLE REINFORCED METAL MATRIX COMPOSITES 1 INTRODUCTION 2 UNIAXIAL AND MULTIAXIAL STRESS-STRAIN RELATIONS 2 1 EXPERIMENTAL OBSERVATIONS 2 2 PREDICTION OF MECHANICAL PROPERTIES BY USING REPRESENTATIVE VOLUME ELEMENTS 3 EFFECT OF INHOMOGENEITY ON THE FATIGUE BEHAVIOR OF PMMCS 3 1 INHOMOGENEOUS PARTICLE SIZE AND SHAPE 3 2 INHOMOGENEOUS PARTICLE DISTRIBUTION IN PMMCS 3 3 EFFECT OF CLUSTERING DISTRIBUTION ON MONOTONIC MECHANICAL BEHAVIOR 3 4 EFFECT OF CLUSTERING DISTRIBUTION ON FATIGUE PROPERTIES OF PMMCS 3 5 INTEGRATED MODELING OF INHOMOGENEOUS DISTRIBUTION OF PARTICLES UNDERGOING LOCALIZED DAMAGE 4 MULTIAXIAL FATIGUE DAMAGE MECHANISMS AND MICRO-MACRO CORRELATION OF PMMCS 4 1 EFFECT OF MULTIAXIAL STRESS STATE ON THE FATIGUE DAMAGE IN PMMCS 4 2 MICRO-DAMAGE CRITERIA FOR PMMCS 4 3 MICRO-MACRO CORRELATION FOR PMMCS UNDERGOING MULTIAXIAL DAMAGE 5 SHORT AND LONG CRACK GROWTH 5 1 SHORT CRACK GROWTH 5 2 LONG CRACK GROWTH 5 3 CRACK-PHRASE DIAGRAM OF PMMCS 5 4 EFFECTS OF PARTICLE SIZE 6 FATIGUE LIFE 6 1 UNIAXIAL FATIGUE RESISTANCE 6 2 MULTIAXIAL FATIGUE 7 SUMMARY CHAPTER 5: MODELING AND PREDICTION OF THE MECHANICAL PROPERTIES OF WOVEN LAMINATES BY THE FINITE ELEMENT METHOD 1 INTRODUCTION 2 APPROACHES FOR THE MECHANICS OF WOVEN COMPOSITES 3 APPLICATION OF THE FINITE ELEMENT METHOD TO WOVEN COMPOSITES 3 1 IDENTIFICATION OF A REPRESENTATIVE VOLUME (RV) 3 2 FINITE ELEMENT MODELING OF RV 3 3 BOUNDARY CONDITIONS ON RV 3 4 CONSTITUTIVE LAWS 3 5 MODELING DAMAGE EVOLUTION 4 PREDICTION OF THE STIFFNESS RESPONSE 5 PREDICTION OF DAMAGE EVOLUTION AND STRENGTH RESPONSE 6 CONCLUSIONS CHAPTER 6: BOUNDARY ELEMENT ANALYSIS OF FRACTURE FAILURE IN ANISOTROPIC COMPOSITE LAMINATES 1 INTRODUCTION 2 ANISOTROPIC FRACTURE MECHANICS 2 1 STRESS INTENSITY FACTORS 2 2 J-INTEGRAL TECHNIQUE 2 3 J-INTEGRAL AND THE RATIO OF RELATIVE DISPLACEMENT TECHNIQUE 3 DUAL BOUNDARY ELEMENT METHOD FOR ANISOTROPIC ELASTOSTATICS 3 1 ELASTOSTATIC ANISOTROPIC FUNDAMENTAL SOLUTIONS 3 2 DISPLACEMENT EQUATION 3 3 TRACTION EQUATION 3 4 DISCRETIZATION AND CRACK MODELING 3 5 COMPUTATION OF PRINCIPAL-VALUE INTEGRALS 3 6 NUMERICAL EXAMPLE 4 QUASI-STATIC CRACK PROPAGATION 4 1 STRAIN ENERGY DENSITY CRITERION 4 2 NUMERICAL EXAMPLE 5 DUAL BOUNDARY ELEMENT METHOD FOR ANISOTROPIC ELASTODYNAMICS 5 1 DUAL RECIPROCITY BOUNDARY ELEMENT TECHNIQUE 5 2 STRESS INTENSITY FACTOR EVALUATION FOR DYNAMIC LOADING 5 3 NUMERICAL EXAMPLE CHAPTER 7: ANALYSIS OF PIEZOELECTRIC COMPOSITE LAMINATES WITH EDGE DELAMINATION 1 INTRODUCTION 2 BASIC EQUATIONS FOR PIEZOELECTRIC COMPOSITE LAMINATES ANALYSIS 2 1 PIEZOELECTRICITY BASIC EQUATIONS AND NOTATION 2 2 GOVERNING EQUATIONS FOR PIEZOELECTRIC LAMINATES 3 BOUNDARY INTEGRAL FORMULATION 3 1 RECIPROCITY STATEMENT FOR PIEZOELECTRIC PLY 3 2 GENERALIZED DISPLACEMENTS BOUNDARY INTEGRAL REPRESENTATION 3 3 BOUNDARY INTEGRAL EQUATIONS 3 4 GENERALIZED STRESS BOUNDARY INTEGRAL REPRESENTATION 3 5 FUNDAMENTAL SOLUTIONS 4 NUMERICAL NODEL 4 1 CONVERGENCE ANALYSIS 5 FUNDAMENTAL CHARACTERISTICS OF PIEZOELECTRIC LAMINATES BEHAVIOR 6 APPLICATION TO THE EDGE DELAMINATION ANALYSIS CHAPTER 8: ANALYSIS OF INTERFACE CRACKS WITH CONTACT IN COMPOSITES BY 2D BEM 1 INTRODUCTION: INTERFACE CRACKS IN FIBER REINFORCED COMPOSITES 2 INTERFACE CRACK MODELS 2 1 ISOTROPIC BIMATERIALS 2 2 ORTHOTROPIC BIMATERIALS 2 3 REMARKS ON APPLICATION OF THE INTERFACE CRACK MODELS 3 INTERFACE CRACK PROPAGATION AND KINKING 3 1 CRACK PATHS IN HOMOGENEOUS ISOTROPIC MATERIALS 3 2 INTERFACE CRACK PATHS 4 BEM FOR 2D ORTHOTROPIC ELASTICITY 4 1 SOME BASIC CONCEPTS OF THE COMPLEX VARIABLE FORMULATION OF 2D ORTHOTROPIC ELASTICITY 4 2 THE SOMIGLIANA DISPLACEMENT IDENTITY 4 3 THE SOMIGLIANA STRESS IDENTITY 4 4 SOME FEATURES OF BEM IMPLEMENTATION 5 WEAK FORMULATION OF INTERFACE/CONTACT CONDITIONS IN BEM WITH NON-CONFORMING MESHES 5 1 CONTACT CONDITIONS 5 2 WEAK FORMULATION OF CONTACT CONDITIONS 5 3 STABILITY CONDITIONS 5 4 INCREMENTAL APPROACH 6 BEM ANALYSIS OF DELAMINATION IN 0°/90° LAMINATE 6 1 STRESS STATE AT THE NEIGHBOURHOOD OF THE CRACK TIP 6 2 ENERGY RELEASE RATE OF THE DELAMINATION CRACK 6 3 CONCLUDING REMARKS 7 BEM ANALYSIS OF PROPAGATION OF FIBER/MATRIX INTERFACE CRACK SUBJECTED TO TRANSVERSAL LOAD 7 1 THE BEM MODEL 7 2 THE INTERFACE CRACK 7 3 KINKING OF THE INTERFACE CRACK 7 4 CONCLUDING REMARKS 8 CONCLUSIONS CHAPTER 9: BOUNDARY ELEMENT ASSESSMENT OF THREE-DIMENSIONAL BIMATERIAL INTERFACE CRACKS 1 INTRODUCTION 2 CRACK TIP FIELD AND BIOMATERIAL INTERFACES 2 1 SINGULAR STRESS FIELD 2 2 NEAR TIP CONTACT ZONE 2 3 THREE-DIMENSIONAL ENERGY RELEASE RATE 2 4 PHASE ANGLES 3 J-INTEGRAL AND STRESS INTENSITY FACTOR COMPUTATION 3 1 THE ENERGY DOMAIN INTEGRAL 3 2 THE INTERACTION INTEGRAL 4 BOUNDARY ELEMENT ANALYSIS 4 1 MULTIDOMAIN BEM FORMULATION 4 2 DISPLACEMENT DERIVATIVES, STRESSES AND STRAINS 4 3 BOUNDARY ELEMENT IMPLEMENTATION 5 EXAMPLES 5 1 AN EXTERNAL CIRCUMFERENTIAL CRACK IN A CYLINDRICAL BAR 5 2 TENSION PANEL WITH A SLANT INTERFACE CRACK 5 3 THICK TENSION BIOMATERIAL PLATE WITH A CENTER INTERFACE CRACK 6 APPLICATION EXAMPLE: FIBER/MATRIX INTERFACE CRACK UNDER TRANSVERSE LOADING 6 1 PRELIMINARIES 6 2 BOUNDARY ELEMENT MODEL 6 3 RESULTS AND DISCUSSION