New Procedures in Nondestructive Testing : Proceedings of the Germany-U.S. Workshop Fraunhofer-Institut, Saarbrücken, Germany, Aug. 30 – Sept. 3, 1982

During recent years an increasing amount of research has been conducted to develop methods and procedures for improving inter­ pretation in nondestructive testing. This research covers appro­ priate testing procedures as well as the algorithms for interpre­ tation. In several cases a state has been reached which allows for implementation. The objective of the workshop was to bring together researchers and industrial users of both countries and colleagues from other countries for a thorough and critical discussion of how far we have come and where we have to go to solve the basic practical problems of interpretation in nondestructive testing and of data acquisition necessary for this purpose. Dr. Dau from EPRI stated during the last International Confer­ ence for Nondestructive Testing in Nuclear Industry that from the point of view of time and money spent research is the smallest part of innovation but, I would like to add in full agreement with him, the most essential. Without successful research innovation is not possible at all; but neither research and invention nor any other step in an innovation procedure can be left out. Our philosophy is to keep researchers involved until the end of the innovation. That means until a new or improved NOT-method is approved under industrial environment and implemented in industry. There can be no doubt that the further we proceed on this long road the more industry will have to be involved and assume the initiative, responsibility and the leading role. Front Matter....Pages I-XXII Front Matter....Pages 1-1 Requirements for the Data Acquisition During Ultrasonic Testing. Search Techniques and Defect Analysis....Pages 3-12 Hardware-Equipment for Automatic Ultrasonic Inspection by the ALOK-Technique....Pages 13-25 Numerical Filtering of Ultrasonic Backscattered Signals....Pages 27-32 Logarithmic Analog-To-Digital Conversion — A New Concept for the Processing of Ultrasonic Data....Pages 33-41 Principles and Practical Applications of Controlled Signals....Pages 43-51 Ultrasonic Plate Testing with a Freely Programmable Electronic System....Pages 53-62 Microprocessor Controlled UT-Equipment....Pages 63-70 EMUS-Probes for Bulk Waves and Rayleigh Waves. Model for Sound Field and Efficiency Calculations....Pages 71-80 Transient Radiation Pattern of Ultrasonic Transducers on Elastic Half-Spaces....Pages 81-92 Front Matter....Pages 93-93 Classification and Reconstruction of Defects by Combined Acoustical Holography and Line-Saft....Pages 95-104 Pulse-Synthesis and Pulse-Adaptation in Ultrasonic Imaging for NDT....Pages 105-112 Acoustic Imaging....Pages 113-125 Visualization of Ultrasound by Optical Holography....Pages 127-131 Inspection of Thick-Walled Components by Ultrasonics and Evaluation of the Data by the ALOK-Technique....Pages 133-150 An Ultrasonic Phased Array System for Defect Classification and Reconstruction....Pages 151-162 Ultrasonic Characterization of Rough Cracks....Pages 163-174 Surface Cracks: Size and Failure Prediction Using Long Wavelength Measurements....Pages 175-192 Characterization of Surface Defects by Rayleigh-Waves....Pages 193-202 Frequency Dependent Interaction of Ultrasonic Waves with Surface-Breaking Cracks....Pages 203-212 Measurement of Crack Depth With Ultrasonic Methods — Through Transmission- and Reflection Modes....Pages 213-228 Front Matter....Pages 93-93 Sizing of Near-Surface Fatigue Cracks in Cladded Pressure Vessels by the Multiple Beam-Satellite Pulse Technique....Pages 229-237 A Feature Based Ultrasonic System for Reflector Classification....Pages 239-250 Front Matter....Pages 251-251 Resonance Scattering Methods for NDT, Acoustics, and RADAR....Pages 253-263 Scattering of Ultrasonic Waves in Single Phase Polycrystalline Metals Including Multiple Scattering....Pages 265-275 Results on Broadband Scattering and Diffraction Suggest Methods to Classify and Reconstruct Defects in QNDE....Pages 277-285 NDE Technique for Detection and Characterization of Porosity....Pages 287-303 Effects of Mutual Coupling Between Different Points of a Scatterer on Imaging....Pages 305-316 Forward and Inverse Ultrasonic Scattering Measurements in Realistic Geometries....Pages 317-336 Bulk Defect Characterization Using Short Wavelength Measurements....Pages 337-354 Front Matter....Pages 355-355 Identification and Parametric Modeling of Transient Waves....Pages 357-367 Ray Methods for Scattering of Ultrasonic Waves by Cracks....Pages 369-379 Inverse Scattering Algorithms....Pages 381-391 Exact Direct and Inverse Scattering in Spatial Frequency/Time Space....Pages 393-402 Application of High Frequency Inverse Scattering to Nondestructive Testing....Pages 403-412 Extensions of Randon’s Projection Theory in RADAR Target Shape Reconstruction....Pages 413-424 Implementation of Inverse-Scattering Algorithms for Characterizing Voids in Gas Turbine Rotor Discs....Pages 425-433 Front Matter....Pages 435-435 Propagation and Scattering of High-Frequency and Pulsed Signals in the Presence of a Concave Boundary....Pages 437-446 Transfer-Functions Characterizing the Propagation of AE-Signals....Pages 447-457 Front Matter....Pages 459-459 Numerical Modeling of Electromagnetic NDT Phenomena....Pages 461-470 A Model for the Interpretation of A.C. Magnetic Stray Flux Measurements....Pages 471-477 Front Matter....Pages 459-459 Developments and Investigations for the Application of the Pulsed Eddy Current Technique....Pages 479-488 Analytical Methods in Flaw Response Modeling and Inversion for EC Testing....Pages 489-495 Defect Classification by Multifrequency Eddy Current....Pages 497-507 Materials Testing by Self-Excited Square-Wave Oscillations with New Lift-Off Compensation....Pages 509-518 Front Matter....Pages 519-519 Measurement of Stress....Pages 521-537 The Use of the Temperature Dependence of Ultrasonic Velocity to Measure Applied and Residual Stresses....Pages 539-550 Determination of Mechanical Stress by Polarized Shear Waves....Pages 551-560 Comparison of Different Methods to Determine Residual Stresses Nondestructively....Pages 561-574 Determination of Residual Stresses Using Micromagnetic Parameters....Pages 575-585 Measuring of Closure Forces with Ultrasonic Diffracted Waves....Pages 587-596 Back Matter....Pages 597-606 1. Probes, Data Acquisition and Data Pre-Processing During Ultrasonic Testing 1.1 Requirements for the Data Acquisition During Ultrasonic Testing. Search Techniques and Defect Analysis 1.2 Hardware-Equipment for Automatic Ultrasonic Inspection by the Alok-Technique 1.3 Numerical Filtering of Ultrasonic Backscattered Signals 1.4 Logarithmic Analog-To-Digital Conversion — a New Concept for the Processing of Ultrasonic Data 1.5 Principles and Practical Applications of Controlled Signals 1.6 Ultrasonic Plate Testing with a Freely Programmable Electronic System 1.7 Microprocessor Controlled Ut-Equipment 1.8 Emus-Probes for Bulk Waves and Rayleigh Waves. Model for Sound Field and Efficiency Calculations 1.9 Transient Radiation Pattern of Ultrasonic Transducers On Elastic Half-Spaces 2. Classification and Reconstruction of Defects by Ultrasonic Testing 2.1 Classification and Reconstruction of Defects by Combined Acoustical Holography and Line-Saft ^ 2.2 Pulse-Synthesis and Pulse-Adaptation in Ultrasonic Imaging for Ndt 2.3 Acoustic Imaging 2.4 Visualization of Ultrasound by Optical Holography 2.5 Inspection of Thick-Walled Components by Ultrasonics and Evaluation of the Data by the Alok-Technique 2.6 An Ultrasonic Phased Array System for Defect Classification and Reconstruction 2.7 Ultrasonic Characterization of Rough Cracks. 2.8 Surface Cracks: Size and Failure Prediction Using Long Wavelength Measurements 2.9 Characterization of Surface Defects by Rayleigh-Waves 2.10 Frequency Dependent Interaction of Ultrasonic Waves with Surface-Breaking Cracks 2.11 Measurement of Crack Depth with Ultrasonic Methods. Through Transmission- and Reflection Modes 2.12 Sizing of Near-Surface Fatigue Cracks in Cladded Pressure Vessels by the Multiple Beam-Satellite Pulse Technique 2.13 a Feature Based Ultrasonic System for Reflector Classification 3. Forward Scattering ^ ^^ 3.1 Resonance Scattering Methods for Ndt, Acoustics, and Radar 3.2 Scattering of Ultrasonic Waves in Single Phase Polycrystalline Metals Including Multiple Scattering 3.3 Results on Broadband Scattering and Diffraction Suggest Methods To Classify and Reconstruct Defects in Qnde 3.4 Nde Technique for Detection and Characterization of Porosity 3.5 Effects of Mutual Coupling Between Different Points of a Scatterer on Imaging 3.6 Forward and Inverse Ultrasonic Scattering Measurements in Realistic Geometries 3.7 Bulk Defect Characterization Using Short Wavelength Measurements 4.1 Identification and Parametric Modeling of Transient Waves 4.2 Ray Methods for Scattering of Ultrasonic Waves by Cracks 4.3 Inverse Scattering Algorithms 4.4 Exact Direct and Inverse Scattering in Spatial Frequency/Time Space 4.5 Application of High Frequency Inverse Scattering To Nondestructive Testing ^ ^^ 4.6 Extensions of Radon’s Projection Theory in Radar Target Shape Reconstruction 4.7 Implementation of Inverse-Scattering Algorithms for Characterizing Voids in Gas Turbine Rotor Discs 5. Acoustic Emission 5.1 Propagation and Scattering of High-Frequency and Pulsed Signals in the Presence of a Concave Boundary 5.2 Transfer-Functions Characterizing the Propagation of Ae-Signals 6. Electrical and Magnetical Methods Theory and Applications 6.1 Numerical Modeling of Electromagnetic Ndt Phenomena 6.2 a Model for the Interpretation of A.C. Magnetic Stray Flux Measurements 6.3 Developments and Investigations for the Application of the Pulsed Eddy Current Technique 6.4 Analytical Methods in Flaw Response Modeling and Inversion for Ec Testing 6.5 Defect Classification by Multi-Multifrequency Eddy Current 6.6 Materials Testing by Self-Excited Square-Wave Oscillations with New Lift-Off Compensation 7. Nondestructive Stress Measurement ^ ^^ 7.1 Measurement of Stress 7.2 The Use of the Temperature Dependence of Ultrasonic Velocity To Measure Applied and Residual Stresses 7.3 Determination of Mechanical Stress by Polarized Shear Waves 7.4 Comparison of Different Methods To Determine Residual Stresses Nondestructively 7.5 Determination of Residual Stresses Using Micromagnetic Parameters 7.6 Measuring of Closure Forces with Ultrasonic Diffracted Waves List of Attendees. ^^