Adhesive Bonding of Aircraft Composite Structures. Non-destructive Testing and Quality Assurance Concepts

Foreword
Preface
Acknowledgements
Contents
Abbreviations
1 Introduction to Recent Advances in Quality Assessment for Adhesive Bonding Technology
	1.1 Introduction
	1.2 Technological and Regulatory Framework
		1.2.1 Adhesive Bonding Processes
		1.2.2 Quality Assurance and Monitoring
		1.2.3 Quality Assessment for Adhesive Bonding
		1.2.4 Ten Heuristic Quality Assessment Principles for Adhesive Bonding Processes
		1.2.5 Extended Non-destructive Testing for Bonding CFRP
		1.2.6 Concepts for ENDT and Quality Assessment in Adhesive Bonding
	1.3 Recent Joint Research for Advancing QA in Adhesive Bonding
		1.3.1 Objectives and Rationale
		1.3.2 Concept and Approaches
		1.3.3 Aims and Key Aspects
		1.3.4 Impacts and Contributions
	1.4 Synopsis
	References
2 Characterization of Pre-bond Contamination and Aging Effects for CFRP Bonded Joints Using Reference Laboratory Methods, Mechanical Tests, and Numerical Simulation
	2.1 Introduction
	2.2 Materials and Sample Geometries
		2.2.1 Basic Materials
		2.2.2 Sample Geometries
	2.3 Manufacturing
		2.3.1 Adherend Manufacturing
		2.3.2 Adherend Pre-bond Contamination
		2.3.3 Bonding
	2.4 Experimental Procedure
		2.4.1 Characterization of CFRP Adherend Surfaces by Reference Methods
		2.4.2 Characterization of CFRP Bonded Samples by Reference Methods
	2.5 Mechanical Testing
		2.5.1 Fracture Toughness Testing
	2.6 Experimental Results
		2.6.1 Spectroscopic Surface Characterization
		2.6.2 Ultrasound Results
		2.6.3 Fracture Toughness Results
		2.6.4 Tensile Testing
		2.6.5 Centrifuge Test Results
	2.7 Numerical Simulation
		2.7.1 FE Model
		2.7.2 Numerical Results
	2.8 Conclusions/Synopsis
	References
3 Extended Non-destructive Testing for Surface Quality Assessment
	3.1 Introduction
	3.2 Aerosol Wetting Test (AWT)
		3.2.1 Principle and Instrumentation
		3.2.2 AWT Results
		3.2.3 AWT Results for the Pilot Level Samples
		3.2.4 AWT Performance in Inline Surface Quality Assessment
	3.3 Optically Stimulated Electron Emission (OSEE)
		3.3.1 Principle and Instrumentation
		3.3.2 OSEE Results
		3.3.3 Performance in Inline Surface Quality Assurance
	3.4 Electronic Nose
		3.4.1 Principle and Instrumentation
		3.4.2 E-nose Methodology
		3.4.3 Final Remarks
	3.5 Laser-Induced Breakdown Spectroscopy (LIBS)
		3.5.1 Principle and Instrumentation
		3.5.2 LIBS Results
		3.5.3 Performance in Inline Surface Quality Assurance
	3.6 Fourier-Transform Infrared Spectroscopy (FTIR)
		3.6.1 Principle and Instrumentation
		3.6.2 FTIR Results
		3.6.3 Performance in Inline Surface Quality Assurance
	3.7 Vibrometry Inspection
		3.7.1 Principle and Instrumentation
		3.7.2 Vibrometry Inspection Results
		3.7.3 Final Remarks
	3.8 Laser-Induced Fluorescence (LIF)
		3.8.1 Principle and Instrumentation
		3.8.2 LIF Results
	3.9 Conclusion
	References
4 Extended Non-destructive Testing for the Bondline Quality Assessment of Aircraft Composite Structures
	4.1 Introduction
	4.2 Electromechanical Impedance
		4.2.1 Principle and Instrumentation
		4.2.2 EMI Results
	4.3 Laser Shocks
		4.3.1 Principle and Instrumentation
		4.3.2 Laser Shock Results
	4.4 Nonlinear Ultrasonic Technique
		4.4.1 Principle and Instrumentation
		4.4.2 Nonlinear Ultrasonic Technique Results
	4.5 Conclusion
	References
5 Extended Non-destructive Testing Technique Demonstration in a Realistic Environment with Technology Assessment
	5.1 Introduction to the Full-Scale Demonstration Event
	5.2 Setup of the Full-Scale Demonstration: Materials, Workflow, and Operations
		5.2.1 Providing Real and Realistic Parts
		5.2.2 Participants and Operations
	5.3 Production User Case
		5.3.1 Workflow Overview
		5.3.2 Release Agent and Fingerprint Contamination
		5.3.3 Bonding Operations
	5.4 Repair User Case
		5.4.1 Workflow Overview
		5.4.2 Description of the Scarfing Operation
		5.4.3 Application of the De-icer and Fingerprint Solutions
		5.4.4 Description of the Bonded Repair Operations
	5.5 Results of the Full-Scale Demonstration: The Representative Production User Case of a CFRP Stringer
		5.5.1 Surface Quality Assessment
		5.5.2 Bonding Quality Assessment
	5.6 Results of the Full-Scale Demonstration: The Representative Bonded Repair User Case of an Airbus A350 Panel
		5.6.1 Surface Quality Assessment After Scarfing
		5.6.2 Bonded Repair Assessment
	5.7 First Evaluation of ENDT Procedures Introducing a Probability of Detection Approach
		5.7.1 Introduction and Motivation
		5.7.2 Input Data for POD Calculation and Compiled Hypotheses
		5.7.3 Examples of the First POD Evaluations
	5.8 The Results of the Full-Scale Demonstration: An Overall Synopsis of the Technology’s Performance
	References
6 Integrating Extended Non-destructive Testing in the Life Cycle Management of Bonded Products—Some Perspectives
	6.1 Introduction
	6.2 Data Transfer Along the Product Life Cycle
	6.3 Customization and Further Advancement of ENDT Tools and Procedures
	6.4 Harmonized Presentation of ENDT Data and Metadata
	6.5 Sensor Systems, Arrays and Networks for Assessing MoL Data
	6.6 Synopsis
	References