The Application of Laser Speckle Interferometry to Measure Strain at Elevated Temperatures and Various Loading Rates


Book Description

This report investigates the application of speckle interferometry for the measurement of strain when a material is subjected to various loading rates and elevated temperature conditions. The Medium Strain Rate Facility at the U.S. Army Materials Technology Laboratory was used to conduct uniaxial tension tests at strain rates of .00001/sec to .1/sec, temperatures up to 250 deg F and heating rates of 250 deg F/sec. Strain was measured by laser speckle interferometry technique and strain gages, the results of both methods were compared. Laser speckle interferometry was also used for the measurement of strain at large deformation, i.e., necking region of tensile specimens. The laser speckle interferometry results are in agreement with strain gage results at strain rates up to .1/sec for temperatures up to 250 deg F. This investigation also indicated laser speckle interferometry would be an excellent noncontact localized strain measuring device for adverse conditions if the following drawbacks were overcome. When using the ruby laser system, only one stress-strain data point can be obtained, the present system is not suited for strain rates over .1/sec and no results can be obtained if the specimen is heated to a point that it begins to emit intense red light. The shortcomings of laser speckle interferometry could be overcome by using another laser and data acquisition system. Keywords: Interferometry, Strain rate, Deformation temperature, Tension, Stress/strain relations, Speckle lasers.










Trends and Applications in Mechanical Engineering, Composite Materials and Smart Manufacturing


Book Description

The fields of Mechanical Engineering, Composite Materials, and Smart Manufacturing find themselves at the heart of a pivotal predicament. As these industries grapple with the demands for efficiency, sustainability, and innovation, a need arises for a unified exploration of the transformative solutions within these domains. At this crucial moment, researchers, academics, and practitioners worldwide need to focus on understanding and solving the complex issues that are hindering progress. Trends and Applications in Mechanical Engineering, Composite Materials and Smart Manufacturing delves into solutions that propel industries, economies, and societies into a future defined by progress and resilience. At its core, this book strives to examine the disciplines of mechanical engineering, composite materials, and smart manufacturing. With the collaborative efforts of diverse experts, it attempts to create a comprehensive resource that not only identifies emerging trends but also unveils their impact on the real world. By acting as a driving force for advancing current research, bridging knowledge gaps, and presenting innovative solutions, the publication contributes significantly to the collective understanding of these disciplines. The goal is to empower scholars, educators, and professionals with the knowledge and insights required to sculpt the future of these increasingly complex industries.




Microelectromechanical Systems and Devices


Book Description

The advances of microelectromechanical systems (MEMS) and devices have been instrumental in the demonstration of new devices and applications, and even in the creation of new fields of research and development: bioMEMS, actuators, microfluidic devices, RF and optical MEMS. Experience indicates a need for MEMS book covering these materials as well as the most important process steps in bulk micro-machining and modeling. We are very pleased to present this book that contains 18 chapters, written by the experts in the field of MEMS. These chapters are groups into four broad sections of BioMEMS Devices, MEMS characterization and micromachining, RF and Optical MEMS, and MEMS based Actuators. The book starts with the emerging field of bioMEMS, including MEMS coil for retinal prostheses, DNA extraction by micro/bio-fluidics devices and acoustic biosensors. MEMS characterization, micromachining, macromodels, RF and Optical MEMS switches are discussed in next sections. The book concludes with the emphasis on MEMS based actuators.










15th Annual Conference on Composites and Advanced Ceramic Materials, Part 2 of 2, Volume 12, Issue 9/10


Book Description

This volume is part of the Ceramic Engineering and Science Proceeding (CESP) series. This series contains a collection of papers dealing with issues in both traditional ceramics (i.e., glass, whitewares, refractories, and porcelain enamel) and advanced ceramics. Topics covered in the area of advanced ceramic include bioceramics, nanomaterials, composites, solid oxide fuel cells, mechanical properties and structural design, advanced ceramic coatings, ceramic armor, porous ceramics, and more.




Mechanics of Fiber and Textile Reinforced Cement Composites


Book Description

Among all building materials, concrete is the most commonly used—and there is a staggering demand for it. However, as we strive to build taller structures with improved seismic resistance or durable pavement with an indefinite service life, we require materials with better performance than the conventional materials used today. Considering the enormous investment in public infrastructure and society’s need to sustain it, the need for new and innovative materials for the repair and rehabilitation of civil infrastructure becomes more evident. These improved properties may be defined in terms of carbon footprint, life-cycle cost, durability, corrosion resistance, strength, ductility, and stiffness. Addressing recent trends and future directions, Mechanics of Fiber and Textile Reinforced Cement Composites presents new opportunities for developing innovative and cost-effective materials and techniques in cement and concrete composites manufacturing, testing, and design. The book offers mathematical models, experimental results, and computational algorithms for efficient designs with fiber and textile reinforced composite systems. It explores alternative solutions using blended cements, innovative reinforcing systems, natural fibers, experimental characterization of key parameters used for design, and optimized designs. Each chapter begins with a detailed introduction, supplies a thorough overview of the existing literature, and sets forth the reasoning behind the experimentation and theory. Documenting the composite action of fibers and textiles, the book develops and explains methods for manufacturing and testing cement composites. Methods to design and analyze structures for reduced weight, increased durability, and minimization of cement use are also examined. The book demonstrates that using a higher volume fraction of fiber systems can result in composites that are quasi-elastic plastic. Speaking to the need to optimize structural performance and sustainability in construction, this comprehensive and cohesive reference requires readers to rethink the traditional design and manufacturing of reinforced concrete structures.