Lester W. Schmerr Jr – författare

This book deals with ultrasonic nondestructive evaluation (NDE) inspections where high frequency waves are used to locate and characterize dangerous flaws (such as cracks) in materials. Ultrasonic NDE flaw inspections involve a very complex combination of electrical, electromechanical, and acoustic/elastic components so that it is important to understand the behavior of those components and their interactions in order to make quantitative flaw measurements. It will be shown that through the use of models and measurements it is now possible to characterize all the elements of an ultrasonic NDE flaw inspection system. Those elements include the pulser/receiver, the cabling, the transducers, and the wave propagation and scattering processes present in an ultrasonic NDE flaw measurement. It will also be demonstrated how to combine models and measurements of those elements to form ultrasonic measurement models which can simulate the flaw signals seen in ultrasonic NDE tests. This comprehensive modeling and measurement capability is described for the first time in this book. There are important engineering applications of this new tech- logy. For example, these ultrasonic models and measurements can be used to design new ultrasonic inspections as well as optimize existing ones. This technology can also help one to extract information on the nature of the flaw present from the measured ultrasonic flaw signals that can then be used to evaluate the safety and reliability of the material being inspected.

This text makes use of symbolic algebra and vector-matrix algebra to demonstrate a new approach to learning statics. Symbolic solutions are obtained, together with the types of solutions covered in other texts, so that students can see the advantages of this new approach.This innovative text is an extension of second-generation vector Statics courses to a new, third-generation matrix-vector Statics course, a course that addresses deformable as well as rigid bodies and employs MATLAB®.MATLAB® is used as a “calculator” whose built-in functions are used to solve statics problems. This text uses vectors and matrices to solve both statically determinate rigid body problems and statically indeterminate problems for deformable bodies.The inclusion of statically indeterminate problems is unique to this text. It is made possible by using symbolic algebra and a new, simplified vector-matrix formulation that combines the equations of equilibrium, the homogeneous solutions to those equations, and a description of the flexibilities found in the deformable elements of a structure to solve directly for the unknown forces/moments.

Build on the foundations of elementary mechanics of materials texts with this modern textbook that covers the analysis of stresses and strains in elastic bodies. Discover how all analyses of stress and strain are based on the four pillars of equilibrium, compatibility, stress-strain relations, and boundary conditions. These four principles are discussed and provide a bridge between elementary analyses and more detailed treatments with the theory of elasticity. Using MATLAB® extensively throughout, the author considers three-dimensional stress, strain and stress-strain relations in detail with matrix-vector relations. Based on classroom-proven material, this valuable resource provides a unified approach useful for advanced undergraduate students and graduate students, practicing engineers, and researchers.

This book deals with ultrasonic nondestructive evaluation (NDE) inspections where high frequency waves are used to locate and characterize dangerous flaws (such as cracks) in materials. Ultrasonic NDE flaw inspections involve a very complex combination of electrical, electromechanical, and acoustic/elastic components so that it is important to understand the behavior of those components and their interactions in order to make quantitative flaw measurements. It will be shown that through the use of models and measurements it is now possible to characterize all the elements of an ultrasonic NDE flaw inspection system. Those elements include the pulser/receiver, the cabling, the transducers, and the wave propagation and scattering processes present in an ultrasonic NDE flaw measurement. It will also be demonstrated how to combine models and measurements of those elements to form ultrasonic measurement models which can simulate the flaw signals seen in ultrasonic NDE tests. This comprehensive modeling and measurement capability is described for the first time in this book. There are important engineering applications of this new tech- logy. For example, these ultrasonic models and measurements can be used to design new ultrasonic inspections as well as optimize existing ones. This technology can also help one to extract information on the nature of the flaw present from the measured ultrasonic flaw signals that can then be used to evaluate the safety and reliability of the material being inspected.

Ultrasound is currently used in a wide spectrum of applications ranging from medical imaging to metal cutting. This book is about using ultrasound in nondestructive evaluation (NDE) inspections. Ultrasonic NDE uses high-frequency acoustic/elastic waves to evaluate components without affecting their integrity or performance. This technique is commonly used in industry (particularly in aerospace and nuclear power) to inspect safety-critical parts for flaws during in-service use. Other important uses of ultrasonic NDE involve process control functions during manufacturing and fundamental materials characterization studies. It is not difficult to set up an ultrasonic NDE measurement system to launch waves into a component and monitor the waves received from defects, such as cracks, even when those defects are deep within the component. It is difficult however to interpret quantitatively the signals received in such an ultrasonic NDE measurement process. For example based on the ultrasonic signal received from a crack, what is the size, shape, and orientation of the crack producing the signal? Answering such questions requires evaluation procedures based on a detailed knowledge of the physics of the entire ultrasonic measurement process. One approach to obtaining such knowledge is to couple quantitative experiments closely with detailed models of the entire ultrasonic measurement system itself. We refer to such models here as ultrasonic NDE measurement models. In other areas of engineering, models have revolutionized how engineering is practiced. A classic example is the impact of the finite-element method on elastic stress analysis.

This book describes a second-generation force-based method emerging from a general formulation where the partial differential equations of elasticity are replaced by equivalent algebraic equations.

Recognizing and demonstrating this important property of symbolic calculations is unique to this book. Examines symbolic and numeric MATLAB tools with engineering examples of linear and nonlinear equations, eigenvalue problems, and differential equations

Fundamentals of Ultrasonic Phased Arrays

This extensively revised and updated second edition of a widely read classic presents the use of ultrasound in nondestructive evaluation (NDE) inspections. Retaining the first edition's use of wave propagation /scattering theory and linear system theory, this volume also adds significant new material including:the introduction of MATLAB® functions and scripts that evaluate key results involving beam propagation and scattering, flaw sizing, and the modeling of ultrasonic systems.elements of Gaussian beam theory and a multi-Gaussian ultrasonic beam model for  bulk wave transducers.a new chapter on the connection between ultrasonic modeling and probability of detection (POD) and reliability models.new and improved derivations of ultrasonic measurement models.updated coverage of ultrasonic simulators that have been developed around the world.Students, engineers, and researchers workingin the ultrasonic NDE field will find a wealth of information on the modeling of ultrasonic inspections and the fundamental ultrasonic experiments that support those models in this new edition.

This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements. The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and seismology communities. A unique feature of this book is that it presents a unified theory of imaging with phased arrays that shows how common imaging methods such as the synthetic aperture focusing technique (SAFT), the total focusing method (TFM), and the physical optics far field inverse scattering (POFFIS) imaging method are all simplified versions of more fundamental and quantitative imaging approaches, called imaging measurement models.To enhance learning, this book first describes the fundamentals of phased array systems using 2-D models, so that the complex 3-D cases normally found in practice can be more easily understood. In addition to giving a detailed discussion of phased array systems, Fundamentals of Ultrasonic Phased Arrays also provides MATLAB® functions and scripts, allowing the reader to conduct simulations of ultrasonic phased array transducers and phased array systems with the latest modeling technology.