On the Fracture Behaviour and the Fracture Pattern Morphology of Tempered Soda-Lime Glass


Book Description

The main criteria for assessing the load-bearing behaviour and risk potential of monolithic glass are its fragmentation and the morphology of the fragments. These depend strongly non-linearly on the strain energy density present in the glass at the time of fracture, which can be converted into fracture energy. Thus, the design and optimization of structural glazing in engineering requires both knowledge of the relevant parameters and mechanisms during the fracture process in glass and an understanding of the characteristics of the fracture structure. Based on fracture mechanics considerations and comprehensive experimental investigations, various aspects and physical quantities of fracture behaviour as well as characteristics and parameters of fracture pattern morphology of fragmented, tempered soda-lime glass were studied and correlated with the stored strain energy. The relationship between fragmentation behavior and strain energy was elaborated using the energy criterion in Linear Elastic Fracture Mechanics (LEFM) related to the initial strain energy before fragmentation and in the post-fracture state. Furthermore, a machine learning inspired approach for the prediction of 2D macro-scale fragmentation of tempered glass was developed and elaborated based on fracture mechanics considerations and statistical analysis of the fracture pattern morphology. A method was deduced and applied in which the fracture pattern of tempered glass is predicted and simulated by Voronoi tessellation of point patterns based on Bayesian spatial point statistics fed with energy conditions in LEFM.




Engineered Transparency 2021


Book Description

This book contains more than 70 articles and presents international trends in structural glazing and facade construction. Renowned authors from all over the world report on current research results and innovative construction projects.




A Concept for Measuring and Evaluating Optical Anisotropy Effects in Tempered Architectural Glass


Book Description

Optical anisotropy effects can occur in building envelopes made of tempered glass. The visual effect has been neglected in the evaluation of the building product and increasingly leads to disputes between the parties involved. This thesis extends the state of knowledge on the cause and perception of optical anisotropic effects and presents a concept for measuring and evaluating them in flat monolithic tempered architectural glass. Initially, an overview and description of current photoelastic measurement methods are given, and the accuracy of the used measurement setups is verified for the first time. The experimental basis for the concept is formed by extensive full-field retardation measurements in the laboratory and field studies of the maximum visibility of the anisotropy effects in an outdoor test rig with accompanying polarization measurements of the sky. Various glass types, geometries, and tempering levels are selected based on typically used products, and their influence on the resulting retardation image is investigated. Determining a correlation of the retardation images with the reflection images of selected test specimens in the outdoor test rig complements the experiments. Based on this, digital evaluation methods are presented, further developed, and applied to the measured retardation images. From the critical analysis of these results, limit values for different anisotropy quality classes are derived, and the concept is complemented. With the implementation of the evaluation methods and the limit values in commercial anisotropy scanners, the quality of each glass pane can be determined directly after tempering in the future. By choosing the highest quality class A, it will be possible in the future to significantly reduce anisotropy effects in constructions made of tempered glass panes.




Characterization of Laminated Safety Glass Interlayers


Book Description

Laminated safety glass enables the safe construction of transparent structures. The mechanical behaviour depends on the polymeric interlayer both in the intact and in the post fracture state. In the present work, the mechanical behaviour of ethylene vinyl acetate-based (EVA) and ionoplastic interlayers is investigated for the intact laminated safety glass condition. In particular, the influence of the semi-crystalline structure on the stiffness behaviour is studied with X-Ray Diffraction, Differential Scanning Calorimetry and Dynamic-Mechanical-Thermal-Analysis. The studies on the mechanical behaviour of the interlayer in the fractured laminated safety glass were carried out with polyvinyl butyral-based (PVB) interlayers. First, the temperature and frequency (time) dependent linearity limits are determined in Dynamic-Mechanical-Thermal-Analyses, second, the nonlinear viscoelastic material behaviour is investigated with tensile relaxation tests at different temperatures and strain levels.




Fractography of Glass


Book Description

As the first major reference on glass fractography, contributors to this volume offer a comprehensive account of the fracture of glass as well as various fracture surface topography. Contributors discuss optical fibers, glass containers, and flatglass fractography. In addition, papers explore fracture origins; the growth of the original flaws of defects; and macroscopic fracture patterns from which fracture patterns evolve. This volume is complete with photographs and schematics.




Glass


Book Description

Glass is a material with essentially unlimited application possibilities. This second edition of a comprehensive reference in glass science, points out the correlation between the performance of industrial processes and practice-relevant properties, such as strength and optical properties. Interdisciplinary in his approach, the author discusses both the science and technology, starting with an outline of history and applications, glass structure, and rheology. The sections on properties include mechanical strength and contact resistance, ageing, mechanics of glass processes, the production and control of residual stresses, high-tech products, and current research and development. Applications include glazing, packaging, optical glass, glass fibers for reinforcement, and abrasive tools. The development of touchscreen technology showed how important were the design and resistance of thin flexible glass and these new thin aluminosilicate glasses are also discussed.




Mechanical Properties of Ceramics


Book Description

A Comprehensive and Self-Contained Treatment of the Theory and Practical Applications of Ceramic Materials When failure occurs in ceramic materials, it is often catastrophic, instantaneous, and total. Now in its Second Edition, this important book arms readers with a thorough and accurate understanding of the causes of these failures and how to design ceramics for failure avoidance. It systematically covers: Stress and strain Types of mechanical behavior Strength of defect-free solids Linear elastic fracture mechanics Measurements of elasticity, strength, and fracture toughness Subcritical crack propagation Toughening mechanisms in ceramics Effects of microstructure on toughness and strength Cyclic fatigue of ceramics Thermal stress and thermal shock in ceramics Fractography Dislocation and plastic deformation in ceramics Creep and superplasticity of ceramics Creep rupture at high temperatures and safe life design Hardness and wear And more While maintaining the first edition's reputation for being an indispensable professional resource, this new edition has been updated with sketches, explanations, figures, tables, summaries, and problem sets to make it more student-friendly as a textbook in undergraduate and graduate courses on the mechanical properties of ceramics.




Light in Forensic Science


Book Description

The identification and quantification of material present and collected at a crime scene are critical requirements in investigative analyses. Forensic analysts use a variety of tools and techniques to achieve this, many of which use light. Light is not always the forensic analyst’s friend however, as light can degrade samples and alter results. This book details the analysis of a range of molecular systems by light-based techniques relevant to forensic science, as well as the negative effects of light in the degradation of forensic evidence, such as the breakage of DNA linkages during DNA profiling. The introductory chapters explain how chemiluminescence and fluorescence can be used to visualise samples and the advantages and limitations of available technologies. They also discuss the limitations of our knowledge about how light could alter the physical nature of materials, for example by breaking DNA linkages during DNA profiling or by modifying molecular structures of polymers and illicit drugs. The book then explains how to detect, analyse and interpret evidence from materials such as illicit drugs, agents of bioterrorism, and textiles, using light-based techniques from microscopy to surface enhanced Raman spectroscopy. Edited by active photobiological and forensic scientists, this book will be of interest to students and researchers in the fields of photochemistry, photobiology, toxicology and forensic science.




Introduction to Glass Science and Technology


Book Description

This book provides a concise and inexpensive introduction for an undergraduate course in glass science and technology. The level of the book has deliberately been maintained at the introductory level to avoid confusion of the student by inclusion of more advanced material, and is unique in that its text is limited to the amount suitable for a one term course for students in materials science, ceramics or inorganic chemistry. The contents cover the fundamental topics of importance in glass science and technology, including glass formation, crystallization, phase separation and structure of glasses. Additional chapters discuss the most important properties of glasses, including discussion of physical, optical, electrical, chemical and mechanical properties. A final chapter provides an introduction to a number of methods used to form technical glasses, including glass sheet, bottles, insulation fibre, optical fibres and other common commercial products. In addition, the book contains discussion of the effects of phase separation and crystallization on the properties of glasses, which is neglected in other texts. Although intended primarily as a textbook, Introduction to Glass Science and Technology will also be invaluable to the engineer or scientist who desires more knowledge regarding the formation, properties and production of glass.




Challenging Glass


Book Description

Contains topics that range from glass joints, fixings and adhesives to architectural designs to the strength, stability and safety of glass. This book also covers issues such as laminates and composite designs, glass lighting, the curving and bending of glass and the many facades of glass.