This book provides the reader with a comprehensive background of semiconductor lasers. It covers their structure, materials, operating principles supported by proper theory, and light power output, as well as conversion efficiency and how frequently the devices can be switched on and off. It also discusses the different lasers working at different wavelengths, viz, ultraviolet, visible, infrared and mid and far infrared regions of electromagnetic spectrum along with proper structure, materials and theory.
Properties, Processing, and Use in Design, Third Edition
Author: David Richerson
Publisher: CRC Press
Category: Technology & Engineering
Ceramic materials have proven increasingly important in industry and in the fields of electronics, communications, optics, transportation, medicine, energy conversion and pollution control, aerospace, construction, and recreation. Professionals in these fields often require an improved understanding of the specific ceramics materials they are using. Modern Ceramic Engineering, Third Edition helps provide this by introducing the interrelationships between the structure, properties, processing, design concepts, and applications of advanced ceramics. This student-friendly textbook effectively links fundamentals and fabrication requirements to a wide range of interesting engineering application examples. A follow-up to our best-selling second edition, the new edition now includes the latest and most important technological advances in the field. The author emphasizes how ceramics differ from metals and organics and encourages the application of this knowledge for optimal materials selection and design. New topics discuss the definition of ceramics, the combinations of properties fulfilled by ceramics, the evolution of ceramics applications, and their importance in modern civilization. A new chapter provides a well-illustrated review of the latest applications using ceramics and discusses the design requirements that the ceramics must satisfy for each application. The book also updates its chapter on ceramic matrix composites and adds a new section on statistical process control to the chapter on quality assurance. Modern Ceramic Engineering, Third Edition offers a complete and authoritative introduction and reference to the definition, history, structure, processing, and design of ceramics for students and engineers using ceramics in a wide array of industries.
Dynamic mechanical analysis (DMA) has left the domain of the rheologist and has become a prevalent tool in the analytical laboratory. However, information on the use of this important tool is still scattered among a range of books and articles. Novices in the field have to dig through thermal analysis, rheology, and materials texts just to find the basics. Updated with new material, expanded practical explanations, and new applications, Dynamic Mechanical Analysis, Second Edition continues to give chemists, engineers, and materials scientists a starting point for applying DMA to their individual fields. It imparts a clear understanding of how DMA works, its advantages, and possible limitations. Additional topics include stress/strain, data handling, experimental technology, test methods, and data analysis. One of the only references dedicated to DMA, this accessible and easy-to-read guide gathers the most pertinent information available on this important technique.
This paper presents results of recently completed studies aimed at characterizing the mechanical properties of irradiated U-10Mo fuel in support of monolithic base fuel qualification. Mechanical properties were evaluated in four-point bending. Specimens were taken from fuel plates irradiated in the RERTR-12 and AFIP-6 Mk. II irradiation campaigns, and tests were conducted in the Hot Fuel Examination Facility (HFEF) at Idaho National Laboratory (INL). The monolithic fuel plates consist of a U-10Mo fuel meat covered with a Zr diffusion barrier layer fabricated by co-rolling, clad in 6061 Al using a hot isostatic press (HIP) bonding process. Specimens exhibited nominal (fresh) fuel meat thickness ranging from 0.25 mm to 0.64 mm, and fuel plate average burnup ranged from approximately 0.4 x 1021 fissions/cm3 to 6.0 x 1021 fissions/cm3. After sectioning the fuel plates, the 6061 Al cladding was removed by dissolution in concentrated NaOH. Pre- and post-dissolution dimensional inspections were conducted on test specimens to facilitate accurate analysis of bend test results. Four-point bend testing was conducted on the HFEF Remote Load Frame at a crosshead speed of 0.1 mm/min using custom-designed test fixtures and calibrated load cells. All specimens exhibited substantially linear elastic behavior and failed in a brittle manner. The influence of burnup on the observed slope of the stress-strain curve and the calculated fracture strength is discussed.
To design a structure or component one must carefully consider the intimate relationship between how the component is supposed to perform and the properties of the material from which it is made. This can be a tricky balancing act, even with isotropic, homogeneous materials. By their very nature, composite materials can present complex problems in the testing of their structural performance. Focusing on composites of advanced fibers in a plastic matrix, this book provides the background and general principles to tackle such problems. Expert contributors examine how these materials react to all types of loading, including tensile, compressive, shear, short- or long-term, and in various environments that might significantly modify their behavior. They explore sample preparation for testing, address tensile, flexural, compression, shear, impact, and out-of-plane testing, and discuss fatigue and fracture mechanics.
The mechanical properties of whole bones, bone tissue, and the bone-implant interfaces are as important as their morphological and structural aspects. Mechanical Testing of Bone and the Bone-Implant Interface helps you assess these properties by explaining how to do mechanical testing of bone and the bone-implant interface for bone-related research
Abstract : Purpose: This paper aims to analyze the elastic-plastic delamination fracture behaviour of multilayered functionally graded four-point bending beam configuration. Design/methodology/approach: The mechanical response of beam is described by a power-law stress-strain relation. The fracture is studied analytically in terms of the strain energy release rate by considering the beam complimentary strain energy. The beam can have an arbitrary number of layers. Besides, each layer may have different thickness and material properties. Also, in each layer, the material is functionally graded along the beam width. A delamination crack is located arbitrary between layers. Thus, the crack arms have different thickness. Findings: The analysis developed is used to elucidate the effects of crack location, material gradient and non-linear behaviour of material on the delamination fracture. It is found that the material non-linearity leads to increase in the strain energy release rate. Therefore, the non-linear behaviour of material should be taken into account in fracture mechanics-based safety design of structural members and components made of multilayered functionally graded materials. The analysis revealed that the strain energy release rate can be effectively regulated by using appropriate material gradients in the design stage of multilayered functionally graded constructions. Originality/value: Delamination fracture behaviour of multilayered functionally graded four-point bending beam configuration is studied in terms of the strain energy release rate by taking into account the material non-linearity.
This study deals with the computational study of asymmetric glass reinforced plastic beams in off-axis four-point bending and the comparison of the induced results with experimental and analytical results. The measurement of the interlaminar shear strength of composite beams, an important design variable in many applications, may be successfully performed by the asymmetric bending test. A three-dimensional finite element analysis is adopted throughout the composite beams in order to, on the one hand, correlate with the experimental results and, on the other hand, to obtain the stress distributions at the supports and at the loading points where usually there is an abrupt variation due to the indentation existing because of the noses. From the finite element analysis and the experimental investigation possible crack initiation positions are determined.
Applications in the Restoration of Ancient Monuments
Author: Stavros K. Kourkoulis
Publisher: Springer Science & Business Media
Category: Technology & Engineering
In this volume scientists from different disciplines present their experience and their scientific work in progress. These concern the properties of a series of stones that have been used for the erection of some of the most important stone monuments of international cultural heritage and are also used today for substitution of missing parts or completion of damaged ones. It deals with the subject globally and contains unpublished research results.
Abstract: Modern printed circuit boards (PCB) are high performance products consisting of metal and dielectric materials in a multi-layered structure. Due to this build-up different failures, such as cracking or delamination, may occur during manufacturing and use leading to failure of the entire electronic device. The mismatch in the thermal expansion coefficients leads to stresses in the structure during temperature change, e.g., during the reflow process. To improve device reliability, it is critical to understand the delamination between different layers and to know the adhesion energy of the interfaces in a PCB. The adhesion energy in test PCBs was determined using four point bending (4PB) experiments before and after 15 reflow cycles. The investigations show that 4PB is applicable for determining the adhesion energy in samples made of halogen free pre-pregs and copper sheets with standard manufacturing processes. Furthermore, the applicability of the analytical adhesion energy calculation in the presence of non-linearities was examined by finite element simulations. It was found that friction between the sample and the pins of the loading device has an influence on the reaction force used for the calculation of the critical energy release rate. Plastic deformation of the 4PB sample, especially in the ductile copper layers, also will affect the analytically determined critical energy release rate. The role of both factors on the analytical approach to measure adhesion energies of PCB interfaces with 4PB will be shown and discussed. Graphical abstract: Highlights: 4 point bending is suitable to measure the interface strength of PCB materials. The influence of reflow cycles on the interface strength can be clearly shown. Friction leads to an overestimation of the calculated interface adhesion. Plastic deformation leads to an overestimation of the calculated interface adhesion.
An excellent book covering the biomechanical and clinical aspects of each ‘element’ of fracture fixation and informs on different effective methods of use in a very concise and lucid manner. Exceedingly valuable for postgraduate students, orthopaedic surgeons and teaching faculties as the book provides the basics and biomechanics of both new and old elements of fracture fixation. The simple sketches and descriptions will help the students and trainees to easily understand the basic and scientific rationales of modern operative fracture treatment. Techniques and implants involved in the management of fracture have been discussed in detail. Provides current knowledge on structure, design, material properties and functions of screws, plates, nails, wires and external fixators. Contains the relevant facts about commonly used implants in a simple and precise language. Essentially deals with metals used in fracture fixation and with the elements in some details. Deals with the structuring of the wreckage of the old bones. Highlights the different instruments used in fracture fixation along with the methods. New to this Edition New chapter on osteoporosis and fracture fixation. New topics included in this edition are: totally novel concepts of screw design and effective plate fixation, methods in osteoporotic bone stabilization, biomechanics of elastic stable intramedullary nail, innovative methods and devices to prevent cutout of sliding hip screw, fresh information on cable fixation and utilization of Kirschner wire, elements of ring fixator, latest materials in fracture treatment and contemporary norms of metal removal.
A boundary value collocation procedure was applied to the Williams stress function to determine values of the stress intensity factor K for single edge in rectangular section specimens subjected to three point bending. The results are presented in terms of the dimensionless quantity Y2 = K2B2W3/M2 where B and W are the specimen thickness and depth and M is the bending moment at midspan. The values of Y2 as a function of relative crack depth a/W for three-point bending are appreciably lower than the corresponding values for pure bending (determined previously by the same method) and decrease as the ratio of support span to specimen depth S/W decreases. Plots of Y2 against a/W are given for values of a/W up to 0. 5 and S/W equal to 4 and 8. The results were relatively insensitive to variations in the spread of the midspan load contact region, which was assumed to be related to the yield strength of the material. The results agreed fairly well with published results derived from experimental compliance measurements; one set gave higher values of Y2 than the present method, and the other set gave lower values. The plane-strain fracture toughness measurement capacity of three-point bend specimens is somewhat lower than that of four- point bend specimens, but the difference is of negligible practical importance.
Recent research is focused on the possibility to coat a metallic alloy with intermetallics or ceramics to improve wear and corrosion resistance, as well as creep behaviour at high temperatures, next to other properties of the alloy. Nowadays, this gains importance due to stricter environment guidelines. Here, we present a model to describe a non-symmetric compound in a high-temperature four-point bending test, performed at 400 ° C. The substrate material is an aluminium alloy AlSi10MgT6, and the coating material is the iron aluminide Fe24Al0.6Nb. Up next, a layer-wise theory is introduced to calculate the forces between substrate and coating. Furthermore, required material parameters are identified, and a new procedure to determine Young’s modulus of a coating is presented. Finally, simulation results are compared to experimental data, illustrating that the presented model is able to describe the material behaviour accurately.
Bulk metallic glasses are a new emerging field of materials with many desirable and unique properties. These amorphous materials have many diverse applications from structural applications to biomedical implants. This book provides a complete overview of bulk metallic glasses. It covers the principles of alloy design, glass formation, processing, atomistic modeling, computer simulations, mechanical properties and microstructures.