Stressed Composite Structures


Book Description

The mechanics of structures with initial stresses is a traditional part of structural mechanics. It is closely related to the important problem of stability of structures. The basic concepts of elastic stability of structures go back to works by Euler (1759) and Bryan (1889). Later, it was found that the problem of deformation of solids with initial stresses is related to variational principles and nonlinear problems in elasticity; see Trefftz (1933), Marguerre (1938), Prager (1947), Hill (1958), Washuzu (1982). Historical detail up to the 1940s can be found in the book by Timoshenko (1953). Observing the basic concepts of the traditional mechanics of stressed structures, we agree that these are suitable for uniform structural elements (plates, beams, and so on) made of homogeneous materials, but not for complex structures (such as a network plate or a lattice mast) or structures made of composite materials (such as fiber reinforced or textile materials). Many concepts of the classical theory, such as a cross section or neutral plane (axis), correspond to no mechanical objects if we consider an inhomogeneous structure. As a result, we come to the conclusion that it would be useful to have a theory of thin inhomogeneous structures developed on the basis of 3-D elasticity theory with no simplifying assumptions (with no a priori hypothesis).




Analysis of process-induced distortions and residual stresses of composite structures


Book Description

The increased application of composite materials in lightweight structures leads to new integral design of structural parts, using the example of, an integral composite landing flap of an Airbus A320 aircraft. This offers possibilities to simplify the process chain, to decrease manufacturing costs and to have fibre fair structural design. The critical disadvantage of large integral designs is that process-induced deformations are a risk factor during the design phase of the manufacturing process, because rework is not always possible. Especially, the aircraft industry with its demands on high qualities / tolerances and the application of hot curing resin systems, requires knowledge-based methods for virtual process design to avoid time- and effort-consuming iterations. This thesis contributes to the understanding of the mechanism behind process-induced distortions and stresses related to the Resin Transfer Moulding (RTM) manufacturing process. The aim is to comprehend the phenomena, to identify related parameters and to present compensation strategies.




Residual Stresses in Composite Materials


Book Description

The residual stress is a common phenomenon in composite materials. They can either add to or significantly reduce material strength. Because of the increasing demand for high-strength, lightweight materials such as composites and their wide range of applications; it is critical that the residual stresses of composite materials are understood and measured correctly.The first edition of this book consists of thirteen chapters divided into two parts. The first part reviews destructive and non-destructive testing (NDT) techniques for measuring residual stresses. There are also additional chapters on using mathematical (analytical and numerical) methods for the calculation of residual stresses in composite materials. These include the simulated hole drilling method, the slitting/crack compliance method, measuring residual stresses in homogeneous and composite glass materials using photoelastic techniques, and modeling residual stresses in composite materials. The second part of the book discusses measuring residual stresses in different types of composites including polymer and metal matrix composites. The addition of nanoparticles to the matrix of polymeric composites as a new technique for the reduction of residual stresses is also discussed.In the Second Edition of this book, each of the original chapters of the first edition has been fully updated, taking into account the latest research and new developments. There are also five new chapters on the theoretical and experimental studies of residual stresses in the composite integrated circuits; residual stresses in additive manufacturing of polymers and polymer matrix composites; residual stresses in metal matrix composites fabricated by additive manufacturing; the eigenstrain based method for the incremental hole-drilling technique; and the estimation of residual stresses in polymer matrix composites using the digital image correlation technique.Residual Stresses in Composite Materials, Second Edition, provides a unique and comprehensive overview of this important topic and is an invaluable reference text for both academics and professionals working in the mechanical engineering, civil engineering, aerospace, automotive, marine, and sporting industries. - Presents the latest developments on theoretical and experimental studies of residual stresses in composites - Reviews destructive and non-destructive testing (NDT) techniques for measuring residual stresses - Discusses residual stresses in the polymer matrix, metal matrix, and ceramic matrix composites - Considers the addition of nanoparticles to the matrix as a new technique for reduction of residual stresses in polymeric composites - Introduces the latest advancements of research on the residual stresses in additive-manufactured polymer and metal matrix composites




Thermal Stress Analysis of Composite Beams, Plates and Shells


Book Description

Thermal Stress Analysis of Composite Beams, Plates and Shells: Computational Modelling and Applications presents classic and advanced thermal stress topics in a cutting-edge review of this critical area, tackling subjects that have little coverage in existing resources. It includes discussions of complex problems, such as multi-layered cases using modern advanced computational and vibrational methods. Authors Carrera and Fazzolari begin with a review of the fundamentals of thermoelasticity and thermal stress analysis relating to advanced structures and the basic mechanics of beams, plates, and shells, making the book a self-contained reference. More challenging topics are then addressed, including anisotropic thermal stress structures, static and dynamic responses of coupled and uncoupled thermoelastic problems, thermal buckling, and post-buckling behavior of thermally loaded structures, and thermal effects on panel flutter phenomena, amongst others. - Provides an overview of critical thermal stress theory and its relation to beams, plates, and shells, from classical concepts to the latest advanced theories - Appeals to those studying thermoelasticity, thermoelastics, stress analysis, multilayered structures, computational methods, buckling, static response, and dynamic response - Includes the authors' unified formulation (UF) theory, along with cutting-edge topics that receive little coverage in other references - Covers metallic and composite structures, including a complete analysis and sample problems of layered structures, considering both mesh and meshless methods - Presents a valuable resource for those working on thermal stress problems in mechanical, civil, and aerospace engineering settings




Composite Structures


Book Description

The papers contained herein were presented at the First International Conference on Composite Structures held at Paisley College of Technology, Paisley, Scotland, in September 1981. This conference was organised and sponsored by Paisley College of Technology in association with The Institution of Mechanical Engineers and The National Engineering Laboratory (UK). There can be little doubt that, within engineering circles, the use of composite materials has revolutionised traditional design concepts. The ability to tailor-make a material to suit prevailing environmental conditions whilst maintaining adequate reinforcement to withstand applied loading is unquestionably an attractive proposition. Significant weight savings can also be achieved by virtue of the high strength-to-weight and stiffness-to-weight characteristics of, for example, fibrous forms of composite materials. Such savings are clearly of paramount importance in transportation engineering and in particular aircraft and aerospace applications. Along with this considerable structural potential the engineer must accept an increased complexity of analysis. All too often in the past this has dissuaded the designer from considering composite materials as a viable, or indeed better, alternative to traditional engineering materials. Inherent prejudices within the engineering profession have also contributed, in no small way, to a certain wariness in appreciating the merits of composites. However, the potential benefits of composite materials are inescapable. The last two decades have seen a phenomenal increase in the use of composites in virtually every area of engineering, from the high technology v vi Preface aerospace application to the less demanding structural cladding situation.




Composite Structures 5


Book Description

The papers contained herein were presented at the Fifth International Conference on Composite Structures (ICCS/5) held at Paisley College of Technology, Scotland in July 1989. The conference was organised and sponsored by Paisley College of Technology. It was co-sponsored by the Scottish Development Agency, the National Engineering Laboratory, the US Air Force European Office of Aerospace Research and Development, the US Army Research, Development and Standardisation Group-UK, Strathclyde Regional Council and Renfrew District Council. It forms a natural and ongoing progression from the highly successful ICCS/1/2/3 and /4 held at Paisley in 1981, 1983, 1985 and 1987 respectively. It has often been said that at the end of each decade there is much to be gained by reflecting on the manifold factors that have influenced the path of one's life. Doubtless there is much truth in that ancient adage. since it is only by subjectively considering the past that a glimmer of the future is possible.




Stress Analysis of Fiber-reinforced Composite Materials


Book Description

Updated and improved, Stress Analysis of Fiber-Reinforced Composite Materials, Hyer's work remains the definitive introduction to the use of mechanics to understand stresses in composites caused by deformations, loading, and temperature changes. In contrast to a materials science approach, Hyer emphasizes the micromechanics of stress and deformation for composite material analysis. The book provides invaluable analytic tools for students and engineers seeking to understand composite properties and failure limits. A key feature is a series of analytic problems continuing throughout the text, starting from relatively simple problems, which are built up step-by-step with accompanying calculations. The problem series uses the same material properties, so the impact of the elastic and thermal expansion properties for a single-layer of FR material on the stress, strains, elastic properties, thermal expansion and failure stress of cross-ply and angle-ply symmetric and unsymmetric laminates can be evaluated. The book shows how thermally induced stresses and strains due to curing, add to or subtract from those due to applied loads.Another important element, and one unique to this book, is an emphasis on the difference between specifying the applied loads, i.e., force and moment results, often the case in practice, versus specifying strains and curvatures and determining the subsequent stresses and force and moment results. This represents a fundamental distinction in solid mechanics.




Engineering Mechanics of Fibre Reinforced Polymers and Composite Structures


Book Description

The book aims at giving an overview of current methods in engineering mechanics of FRP components and structures as well as hybrid components and structures. Main emphasis is on basic micro and macro mechanics of laminates. Long as well as short fibre composites are studied, and criteria for different kinds of rupture are treated. Micromechanical considerations for material characterization and mechanisms of static ductile and brittle rupture are studied, as well as FRP structures under thermal and dynamic loading programs. Optimum design and manufacture situations are described as well. The book makes designers familiar with the opportunities and limitations of modern high quality fibre composites. Practical engineering applications of the described analytical and numerical methods are also presented.




Engineered Repairs of Composite Structures


Book Description

Engineered Repairs of Composite Structures provides a detailed discussion, analysis, and procedures for effective and efficient repair design of advanced composite structures. It discusses the identification of damage types and the effect on structural integrity in composite structures, leading to the design of a repair scheme that focusses on the restoration of the structural integrity and damage tolerance. This book teaches the reader to better understand effective and efficient repair design, allowing for more structurally effective repairs of damaged composite structures. It also discusses the application of the repair and what is needed in the forming of the composite repair to meet the engineering design requirements. Aimed at materials engineers, mechanical engineers, aerospace engineers, and civil engineers, this practical work is a must have for any industry professional working with composite structures.




Properties for Design of Composite Structures


Book Description

PROPERTIES FOR DESIGN OF COMPOSITE STRUCTURES A comprehensive guide to analytical methods and source code to predict the behavior of undamaged and damaged composite materials In Properties for Design of Composite Structures: Theory and Implementation Using Software, distinguished researcher Dr. Neil McCartney delivers a unique and insightful approach to the development of predictive methods for the properties of undamaged and damaged laminated composite materials. The book focuses on presenting compact analytical formulae for several important effective properties—including mechanical, thermal, and electrical—that can be applied to a variety of reinforcement geometries. The author introduces a compact notation that enables an explicit treatment of laminate property determination, including the out-of-plane shear properties required for three-dimensional numerical simulations of structural features using finite and boundary element analyses. There is also a detailed consideration of ply crack closure and a useful study of the interrelationships between the effective thermoelastic constants of damaged laminates. The book also offers: A thorough introduction to the principles and formulae for homogenous materials and applications, including continuum and fracture concepts for homogeneous materials A comprehensive exploration of the properties of undamaged composites, including undamaged composite materials with multiple phases and the properties of a single undamaged lamina Practical discussions of the properties of damaged composites, including matrix cracking in UD composites and damaged laminates Consideration of effects of delamination, fatigue, and environmentally induced damage In-depth examinations of derivations of key results, including the analysis of bridged cracks and stress transfer mechanics for cross-ply and general symmetric laminates Perfect for composite design engineers in all types of material-supplying industries and manufacturing companies, Properties for Design of Composite Structures: Theory and Implementation Using Software will also earn a place in the libraries of undergraduate and graduate students in engineering, aerospace, and materials departments.