Riccio Damage Growth in Aerospace Composites

1. Auflage 2015
ISBN: 978-3-319-04004-2
Verlag: Springer International Publishing
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 279 Seiten

Reihe: Springer Aerospace Technology

This book presents novel methods for the simulation of damage evolution in aerospace composites that will assist in predicting damage onset and growth and thus foster less conservative designs which realize the promised economic benefits of composite materials. The presented integrated numerical/experimental methodologies are capable of taking into account the presence of damage and its evolution in composite structures from the early phases of the design (conceptual design) through to the detailed finite element method analysis and verification phase. The book is based on the GARTEUR Research Project AG-32, which ran from 2007 to 2012, and documents the main results of that project. In addition, the state of the art in European projects on damage evolution in composites is reviewed. While the high specific strength and stiffness of composite materials make them suitable for aerospace structures, their sensitivity to damage means that designing with composites is a challenging task. The new approaches described here will prove invaluable in meeting that challenge.

Autoren/Hrsg.

Riccio, Aniello

Inhaltsverzeichnis

1;Contents;6
2;1 Introduction;8
2.1;1.1 State of the Art of European Projects on Composites Damage Management;8
2.2;1.2 AG-32 Objectives and Relationships with Previous Projects;11
2.3;1.3 AG-32 Work Breakdown Structure and Presentation of Results;12
3;Part I Detailed Methodologies for Damage Growth in Aerospace Composites;14
4;2 Detailed Methodologies for Integrated Delamination Growth and Fiber-Matrix Damage Progression Simulation;15
4.1;2.1 Introduction;15
4.2;2.2 Objectives;17
4.3;2.3 Description of the Method;18
4.3.1;2.3.1 Phenomenology;18
4.3.2;2.3.2 Theoretical Background;20
4.3.2.1;2.3.2.1 Intra-laminar Damage: A Progressive Damage Procedure;20
4.3.2.2;2.3.2.2 Stress Evaluation;20
4.3.2.3;2.3.2.3 Failure Criteria and Material Properties Degradation Rules;21
4.3.2.4;2.3.2.4 Inter-laminar Damage: Energy Release Rate and Crack Growth Criteria;23
4.3.3;2.3.3 Numerical Implementations in B2000;24
4.3.3.1;2.3.3.1 Progressive Damage Brick Element;25
4.3.3.2;2.3.3.2 Interface Fracture Element for Delamination Growth;26
4.3.3.3;2.3.3.3 Contact Element;28
4.3.4;2.3.4 Numerical Tool for Intra-laminar Damage and Delamination Growth;28
4.3.5;2.3.5 Benefits and Limitations of the Method and Added Value with Respect to the State of the Art;30
4.4;2.4 Validation of the Developed Numerical Tools: B2000 Applications;31
4.4.1;2.4.1 Tension-Loaded Laminate with Hole;31
4.4.2;2.4.2 Composite Delaminated Panels Loaded in Compression;34
4.4.3;2.4.3 Specimen Configuration #SS3;38
4.4.4;2.4.4 Specimen Configuration #SS4;42
4.4.5;2.4.5 Specimen Configuration #SS5;45
4.5;2.5 ABAQUSTM Exploratory Applications: Stiffened Panels with Embedded Delaminations and a Skin-Stringer Debonding;47
4.5.1;2.5.1 Simulating the Damage Onset and Evolution in ABAQUS;48
4.5.1.1;2.5.1.1 Inter-laminar Damage;48
4.5.1.2;2.5.1.2 Intra-Laminar Damage;49
4.5.2;2.5.2 Stiffened Panel with an Embedded Bay Delamination;50
4.5.3;2.5.3 Stiffened Panel with an Skin-Stringer Debonding;56
4.6;References;64
5;3 Delamination and Debonding Growth in Composite Structures;68
5.1;3.1 Introduction;68
5.2;3.2 Delamination Growth;70
5.2.1;3.2.1 Virtual Crack Closure Technique Fundamentals;71
5.2.2;3.2.2 Validation Benchmark Definition;72
5.2.3;3.2.3 FE Model Definition and Buckling Simulations;72
5.2.4;3.2.4 Delamination Growth Algorithm;75
5.2.5;3.2.5 Correlation Between FE Simulations and Tests;77
5.2.6;3.2.6 Mesh Size Effect;78
5.2.7;3.2.7 Comparison Among Mixed-Mode Failure Criteria;78
5.2.8;3.2.8 Conclusions and Future Work;80
5.3;3.3 Debonding Growth;81
5.3.1;3.3.1 FE Modelling of DCB Coupons;82
5.3.2;3.3.2 Cohesive Zone (CZ) Elements;83
5.3.3;3.3.3 Mesh Dependency;84
5.3.4;3.3.4 Experimental Results on DCB Coupons;86
5.3.5;3.3.5 Correlation FE Model Simulation—Tests—DCB Coupons;88
5.3.6;3.3.6 Conclusions and Future Work;91
5.4;References;92
6;4 Delamination Growth in Composite Plates Under Fatigue Loading Conditions;94
6.1;4.1 Introduction;94
6.2;4.2 Fatigue Degradation: Linear Approach;95
6.3;4.3 Fatigue Degradation: Non-linear Approach;97
6.4;4.4 Numerical Application: Delamination Growth in a Composite Panel Subjected to Fatigue Load;99
6.5;4.5 Numerical Application: Sensitivity Analysis of Damage Propagation of a Delaminated Composite Panel Under Fatigue Load;104
6.6;4.6 Conclusions;109
6.7;References;109
7;5 Influence of Intralaminar Damage on the Delamination Crack Evolution;111
7.1;5.1 Introduction;111
7.2;5.2 Influence of Intralaminar Damage on the Interlaminar Damage Evolution;113
7.2.1;5.2.1 Influence of Intralaminar Damage on Delamination Crack Onset;113
7.2.1.1;5.2.1.1 Identification of the Intrinsic Out-of-Plane Tensile Strength;113
7.2.1.2;5.2.1.2 Determination of the Influence of Intralaminar Damages on the Onset of Delamination;117
7.2.2;5.2.2 Influence of Intralaminar Damage on Delamination Crack Propagation;119
7.2.2.1;5.2.2.1 The Tensile Flexure Test on Notched Specimen;120
7.2.2.1.1;Description of the Experimental Procedure;120
7.2.2.1.2;Description of the Experimental Device;121
7.2.2.1.3;Experimental Observations;122
7.2.2.1.4;Identification of the Interface Toughness in a T700GCM21 CarbonEpoxy Laminate;123
7.2.2.2;5.2.2.2 Demonstration of the Influence of Intralaminar Damage on the Interfacial Fracture Toughness;124
7.3;5.3 Modeling the Effect of Intralaminar Damage on the Interlaminar Damage Evolution;126
7.3.1;5.3.1 Cohesive Zone Model for Modeling the Interlaminar Damage;126
7.3.1.1;5.3.1.1 General Framework of the Cohesive Zone Model;126
7.3.1.2;5.3.1.2 Damage Evolution Law of the Interlaminar Damage;128
7.3.1.3;5.3.1.3 Determination of the Onset Criterion with Reinforcement of the Interfacial Strengths Under Out-of-Plane CompressionShearing Loadings;129
7.3.2;5.3.2 Damage Evolution Law of Intralaminar Damage;132
7.3.3;5.3.3 Damage Evolution Law of Delamination Including the Intralaminar Damage Effect;135
7.3.4;5.3.4 Implementation in a Finite Element Code;136
7.4;5.4 Application on Structural Test Cases;137
7.5;5.5 Conclusions;140
7.6;References;141
8;6 Microdamage Modeling in Laminates;145
8.1;6.1 Introduction;145
8.2;6.2 Experimental Methods for Damage State Characterization;150
8.3;6.3 Damage Initiation and Growth;154
8.3.1;6.3.1 Initiation Stress and Propagation Stress;154
8.3.2;6.3.2 Statistical Nature of Initiation Stress Distribution;157
8.3.3;6.3.3 Energy Release Rate Based Analysis of Intralaminar Crack Propagation;162
8.4;6.4 Stiffness of Damaged Laminate;168
8.4.1;6.4.1 Calculation Expressions;168
8.4.2;6.4.2 Examples of Calculation and Experiments;170
8.5;6.5 Conclusions;173
8.6;References;175
9;Part II Fast Methodologies for Damage Growth in Aerospace Composites;178
10;7 Finite Element Study of Delaminations in Notched Composites;179
10.1;7.1 Finite Element Delamination Study of a Notched Composite Plate;179
10.1.1;7.1.1 Element Type, Mesh, Boundary Condition and Applied Load;181
10.1.2;7.1.2 Assumption and Particular Settings;181
10.1.3;7.1.3 Method;182
10.2;7.2 Results;182
10.2.1;7.2.1 Structural Response;182
10.2.2;7.2.2 Delamination;183
10.2.2.1;7.2.2.1 Delamination Initiation;183
10.2.2.2;7.2.2.2 Delamination Growth;184
10.3;7.3 Comparison and Discussion;185
10.4;7.4 Conclusions;186
10.5;References;187
11;8 Effect of the Damage Extension Through the Thickness on the Calculation of the Residual Strength of Impacted Composite Laminates;188
11.1;8.1 Introduction;188
11.2;8.2 Delamination Buckling and Growth;190
11.2.1;8.2.1 Delamination Buckling Theory;191
11.2.2;8.2.2 Approximate Calculation of Strain Energy Release Rate;192
11.3;8.3 Characterization of Damage;194
11.3.1;8.3.1 Numerical Implementation;194
11.3.2;8.3.2 Description of Method;195
11.3.3;8.3.3 Analytical Tool to Predict Damage Extension;197
11.4;8.4 Benefits and Limitations of the Method and Added Value with Respect to the State of the Art;199
11.5;References;199
12;9 A Fast Numerical Methodology for Delamination Growth Initiation Simulation;200
12.1;9.1 Introduction;200
12.2;9.2 Description of the Method: Theoretical Background;203
12.3;9.3 Finite Element Implementation;211
12.4;9.4 Numerical Application: Sensitivity Analysis on a Stringer-Stiffened Panel with an Embedded Delamination;213
12.5;9.5 Benefits and Limitations of the Method and Added Value with Respect to the State of the Art;216
12.6;References;219
13;Part III Manufacturing and Testing;222
14;10 An Experimental Study on the Strength of Out of Plane Loaded Composite Structures;223
14.1;10.1 Introduction;223
14.2;10.2 Mechanical Tests;224
14.2.1;10.2.1 Bending and Compressions Tests;224
14.2.2;10.2.2 Inspection—NDT and Fractography;225
14.3;10.3 Experimental Results;226
14.3.1;10.3.1 Bending Tests of Impacted Laminates;227
14.3.2;10.3.2 Bending Test of Notched Laminates;228
14.3.3;10.3.3 Fractoraphic Results;228
14.4;10.4 Conclusions;229
14.5;References;230
15;11 Buckling and Collapse Tests Using Advanced Measurement Systems;231
15.1;11.1 Introduction;231
15.2;11.2 Definitions;232
15.3;11.3 DLR Buckling Test Facility;233
15.4;11.4 Preparation of the Test Structures;235
15.5;11.5 Advanced Measurement Systems;236
15.5.1;11.5.1 Before the Test;236
15.5.1.1;11.5.1.1 Non-destructive Testing and Thickness Measurement;236
15.5.1.2;11.5.1.2 ATOS System—Optical Measurement of Imperfections;236
15.5.2;11.5.2 During the Test;237
15.5.2.1;11.5.2.1 ARAMIS System—Optical Measurement of Deformations;237
15.5.2.2;11.5.2.2 Thermography—Measurement of Degradation;239
15.5.2.3;11.5.2.3 Lamb-Waves—Measurement of Degradation;240
15.6;11.6 Material Properties;241
15.7;11.7 Test Results;242
15.7.1;11.7.1 Cyclic Tests and Collapse Test of a Stiffened Panel;242
15.7.2;11.7.2 Buckling Test of an Unstiffened Cylinder;247
15.8;References;248
16;12 Vacuum Infusion Manufacturing of CFRP Panels with Induced Delamination;249
16.1;12.1 Introduction;249
16.2;12.2 Liquid Composite Molding Overview;250
16.3;12.3 Experimental Activity;255
16.3.1;12.3.1 FRCP Manufacturing;255
16.3.2;12.3.2 Microscopy Analysis;259
16.4;12.4 Conclusions;259
16.5;References;261
17;13 Lock-in Thermography to Detect Delamination in Carbon Fibres Reinforced Polymers;262
17.1;13.1 Introduction;262
17.2;13.2 Non-destructive Testing with IRT;263
17.2.1;13.2.1 Basics on Lockin Thermography;264
17.3;13.3 Experimental Analysis;265
17.3.1;13.3.1 Specimens Preparation;265
17.3.2;13.3.2 Test Setup;266
17.4;13.4 Results and Discussion;268
17.4.1;13.4.1 Qualitative Analysis;269
17.4.2;13.4.2 Quantitative Analysis;273
17.5;13.5 Conclusions;276
17.6;References;277