The Old and New... A Narrative on the History of the Society for Experimental Mechanics


Book Description

The field of Experimental Mechanics has evolved substantially over the past 100 years. In the early years, the field was primarily comprised of applied physicists, civil engineers, railroad engineers, and mechanical engineers. The field defined itself by those who invented, developed, and refined experimental tools and techniques, based on the latest technologies available, to better understand the fundamental mechanics of materials and structures used to design many aspects of our everyday life. What the early experimental mechanician measured, observed, and evaluated were things like stress, strain, fracture, and fatigue, to name a few, which remain fundamental to the field today. This book guides you through a chronology of the formation of the Society for Experimental Mechanics, and its ensuing evolution. The Society was founded in 1935 by a very small group of individuals that understood the value of creating a common forum for people working in the field of Applied Mechanics of Solids, where extensive theoretical developments needed the input of experimental validation. A community of individuals who—through research, applications, sharp discussion of ideas—could fulfill the needs of a nation rapidly evolving in the technological field. The founders defined, influenced, and grew the field of what we now call Experimental Mechanics. Written as a narrative, the author describes, based on input from numerous individuals and personal experiences, the evolution of the New England Photoelasticity Conference to what we know today as the Society for Experimental Mechanics (SEM). The narrative is the author's perspective that invites members of the Society to contribute to the story by adding names of individuals, institutions, and technologies that have defined the Society over the past 75 years. Many of the key individuals who greatly influenced the advancement of the field of Experimental Mechanics are mentioned. These individuals are, in many ways, the founders of the field who have written textbooks, brought their teaching leadership and experiences to the classroom, worked on the Apollo project, and invented testing, evaluation, and measurement equipment that have shaped the fields of engineering. SEM's international membership is highly represented by those in academia, as you will read, although there has always been a powerful balance and contribution from industry and research organizations across the globe. The role of the experimental mechanician is defined, in many ways, through the individual legacies shared in the following pages....legacies that define the past and create the foundation for what is now and what is to come.




The Old and New...


Book Description

The field of Experimental Mechanics has evolved substantially over the past 100 years. In the early years, the field was primarily comprised of applied physicists, civil engineers, railroad engineers, and mechanical engineers. The field defined itself by those who invented, developed, and refined experimental tools and techniques, based on the latest technologies available, to better understand the fundamental mechanics of materials and structures used to design many aspects of our everyday life. What the early experimental mechanician measured, observed, and evaluated were things like stress, strain, fracture, and fatigue, to name a few, which remain fundamental to the field today. This book guides you through a chronology of the formation of the Society for Experimental Mechanics, and its ensuing evolution. The Society was founded in 1935 by a very small group of individuals that understood the value of creating a common forum for people working in the field of Applied Mechanics of Solids, where extensive theoretical developments needed the input of experimental validation. A community of individuals who—through research, applications, sharp discussion of ideas—could fulfill the needs of a nation rapidly evolving in the technological field. The founders defined, influenced, and grew the field of what we now call Experimental Mechanics. Written as a narrative, the author describes, based on input from numerous individuals and personal experiences, the evolution of the New England Photoelasticity Conference to what we know today as the Society for Experimental Mechanics (SEM). The narrative is the author's perspective that invites members of the Society to contribute to the story by adding names of individuals, institutions, and technologies that have defined the Society over the past 75 years. Many of the key individuals who greatly influenced the advancement of the field of Experimental Mechanics are mentioned. These individuals are, in many ways, the founders of the field who have written textbooks, brought their teaching leadership and experiences to the classroom, worked on the Apollo project, and invented testing, evaluation, and measurement equipment that have shaped the fields of engineering. SEM's international membership is highly represented by those in academia, as you will read, although there has always been a powerful balance and contribution from industry and research organizations across the globe. The role of the experimental mechanician is defined, in many ways, through the individual legacies shared in the following pages....legacies that define the past and create the foundation for what is now and what is to come.




Structure-Property Relationships under Extreme Dynamic Environments


Book Description

The inelastic response and residual mechanical properties acquired from most shock compressed solids are quite different from those acquired from quasi-static or moderate strain rates. For instance, the residual hardness of many shock compressed metals has been found to be considerably lower than those loaded under quasi-static conditions to the same maximum stress. However, the residual hardness of shock compressed metals is much higher than those loaded quasi-statically to the same total strain. These observations suggest that the deformation mechanisms active during inelastic deformation under shock compression and quasi-static or moderate rates may be quite different. Therefore, the primary objective of this short book is to offer the reader a concise introduction on the Structure-Property Relationships concerning shock compressed metals and metallic alloys via shock recovery experiments. The first phase of the book, chapters 1 through 3 provides a brief historical perspective on the structure-property relationships as it pertains to shock compression science, then plastic deformation in shock compressed metals and metallic alloys is described in terms of deformation slip, deformation twinning, and their consequences to spall failure. Existing knowledge gaps and limitations on shock recovery experiments are also discussed. The fundamentals of shock wave propagation in condensed media are presented through the formation and stability of shock waves, then how they are treated using the Rankine-Hugoniot jump relations derived from the conservation of mass, momentum, and energy. The equation of states which govern the thermodynamic transition of a material from the unshock state to the shock state is briefly described and the elastic-plastic behavior of shock compressed solids is presented at the back end of the first phase of this book. The second phase of the book describes the geometry and design of shock recovery experiments using explosives, gas and powder guns. Then results derived from the residual mechanical properties, microstructure changes, and spall failure mechanisms in shock compressed metals and metallic alloys with FCC, BCC, and HCP crystal lattice structures are presented. Also, results on the residual microstructure of explosively compacted powders and powder mixtures are presented. Lastly, the book closes with the new frontiers in shock recovery experiments based on novel materials, novel microscopes, novel mechanical processing techniques, and novel time-resolved in-situ XRD shock experiments.




The Integrated Test Analysis Process for Structural Dynamic Systems


Book Description

Over the past 60 years, the U.S. aerospace community has developed, refined, and standardized an integrated approach to structural dynamic model verification and validation. One name for this overall approach is the Integrated Test Analysis Process (ITAP) for structural dynamic systems. ITAP consists of seven sequential tasks, namely: (1) definition of test article finite element models; (2) systematic modal test planning; (3) measured data acquisition; (4) measured data analysis; (5) experimental modal analysis; (6) systematic test-analysis correlation; and (7) reconciliation of finite element models and modal test data. Steps 1, 2, and 7 rely strictly on mathematical model disciplines, and steps 3 and 4 rely on laboratory disciplines and techniques. Current industry practice of steps 5 and 6 calls for interaction of mathematical model and laboratory disciplines, which compromises the objectivity of both modeling and laboratory disciplines. This book addresses technical content, strategies, and key relevant experiences related to all steps of ITAP, except for measured data acquisition which is the specialized domain of highly experienced laboratory professionals who contend with mechanical and electrical practicalities of instrumentation, excitation hardware, and data collection systems.




Handbook of Experimental Structural Dynamics


Book Description

The SEM Handbook of Experimental Structural Dynamics stands as a comprehensive overview and reference for its subject, applicable to workers in research, product design and manufacture, and practice. The Handbook is devoted primarily to the areas of structural mechanics served by the Society for Experimental Mechanics IMAC community, such as modal analysis, rotating machinery, structural health monitoring, shock and vibration, sensors and instrumentation, aeroelasticity, ground testing, finite element techniques, model updating, sensitivity analysis, verification and validation, experimental dynamics sub-structuring, quantification of margin and uncertainty, and testing of civil infrastructure. Chapters offer comprehensive, detailed coverage of decades of scientific and technologic advance and all demonstrate an experimental perspective. Several sections specifically discuss the various types of experimental testing and common practices utilized in the automotive, aerospace, and civil structures industries. · History of Experimental Structural Mechanics · DIC Methods - Dynamic Photogrammetry · LDV Methods · Applied Digital Signal Processing · Introduction to Spectral - Basic Measurements · Structural Measurements - FRF · Random and Shock Testing · Rotating System Analysis Methods · Sensors Signal Conditioning Instrumentation · Design of Modal Tests · Experimental Modal Methods · Experimental Modal Parameter Evaluation · Operating Modal Analysis Methods · Analytical Numerical Substructuring · Finite Element Model Correlation · Model Updating · Damping of Materials and Structures · Model Calibration and Validation in Structures · Uncertainty Quantification: UQ, QMU and Statistics · Nonlinear System Analysis Methods (Experimental) · Structural Health Monitoring and Damage Detection · Experimental Substructure Modeling · Modal Modeling · Response (Impedance) Modeling · Nonlinear Normal Mode Analysis Techniques (Analytical) · Modal Modeling with Nonlinear Connection Elements (Analytical) · Acoustics of Structural Systems (VibroAcoustics) · Automotive Structural Testing · Civil Structural Testing · Aerospace Perspective for Modeling and Validation · Sports Equipment Testing · Applied Math for Experimental Structural Mechanics Contributions present important theory behind relevant experimental methods as well as application and technology. Topical authors emphasize and dissect proven methods and offer detail beyond a simple review of the literature. Additionally, chapters cover practical needs of scientists and engineers who are new to the field. In most cases, neither the pertinent theory nor, in particular, the practical issues have been presented formally in current academic textbooks. Each chapter in the Handbook represents a ’must read’ for someone new to the subject or for someone returning to the field after an absence. Reference lists in each chapter consist of the seminal papers in the literature. This Handbook stands in parallel to the SEM Handbook of Experimental Solid Mechanics, where this Handbook focuses on experimental dynamics of structures at a macro-scale often involving multiple components and materials where the SEM Handbook of Experimental Solid Mechanics focuses on experimental mechanics of materials at a nano-scale and/or micro-scale.




Mechanics of Materials Laboratory Course


Book Description

This book is designed to provide lecture notes (theory) and experimental design of major concepts typically taught in most Mechanics of Materials courses in a sophomore- or junior-level Mechanical or Civil Engineering curriculum. Several essential concepts that engineers encounter in practice, such as statistical data treatment, uncertainty analysis, and Monte Carlo simulations, are incorporated into the experiments where applicable, and will become integral to each laboratory assignment. Use of common strain (stress) measurement techniques, such as strain gages, are emphasized. Application of basic electrical circuits, such as Wheatstone bridge for strain measurement, and use of load cells, accelerometers, etc., are employed in experiments. Stress analysis under commonly applied loads such as axial loading (compression and tension), shear loading, flexural loading (cantilever and four-point bending), impact loading, adhesive strength, creep, etc., are covered. LabVIEW software with relevant data acquisition (DAQ) system is used for all experiments. Two final projects each spanning 2-3 weeks are included: (i) flexural loading with stress intensity factor determination and (ii) dynamic stress wave propagation in a slender rod and determination of the stress-strain curves at high strain rates. The book provides theoretical concepts that are pertinent to each laboratory experiment and prelab assignment that a student should complete to prepare for the laboratory. Instructions for securing off-the-shelf components to design each experiment and their assembly (with figures) are provided. Calibration procedure is emphasized whenever students assemble components or design experiments. Detailed instructions for conducting experiments and table format for data gathering are provided. Each lab assignment has a set of questions to be answered upon completion of experiment and data analysis. Lecture notes provide detailed instructions on how to use LabVIEW software for data gathering during the experiment and conduct data analysis.







Catalogue of the Reference Library


Book Description