Download or read book Finite Element Analysis of Viscoelastic Core Sandwich Structures written by Xiaomin Li and published by . This book was released on 2002 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Analysis for Sandwich Structures with a Viscoelastic constrained Layer written by Yeun S. Jeung and published by . This book was released on 1998 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Modeling of Sandwich Structures with Viscoelastic Core written by Kamel Amichi and published by . This book was released on 2009 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Analysis written by Farzad Ebrahimi and published by BoD – Books on Demand. This book was released on 2012-10-10 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past few decades, the Finite Element Analysis (FEA) has been developed into a key indispensable technology in the modeling and simulation of various engineering systems. The present book is a result of contributions of experts from international scientific community and collects original and innovative research studies on recent applications of FEA in five major topics of mechanical engineering namely, fluid mechanics and heat transfer, machine elements analysis and design, machining and product design, wave propagation and failure-analysis and structural mechanics and composite materials. It is meant to provide a small but valuable sample of contemporary research activities around the world in this field and it is expected to be useful to a large number of researchers. The introductions, data, and references in this book will help the readers know more about this topic and help them explore this exciting and fast-evolving field.

Download or read book Analyses of Deformation in Viscoelastic Sandwich Composites Subject to Moisture Diffusion written by Nikhil P. Joshi and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sandwich composites with polymer foam core are currently used in load-bearing components in buildings and naval structures due to their high strength to weight and stiffness to weight ratios, excellent thermal insulation, and ease of manufacturing. During their service time, sandwich composites are exposed to various external mechanical and hygro-thermal stimuli. It is known that the constituent properties of the sandwich composites are greatly influenced by the temperature and moisture fields. For example extreme temperature changes and humid environmental conditions can significantly degrade the stiffness and strength of the polymer foam core. This study analyzes the effect of moisture diffusion on the deformation of viscoelastic sandwich composites, which are composed of orthotropic fiber-reinforced laminated skins and viscoelastic polymeric foam core. It is assumed that the elastic and time-dependent (transient) moduli at any particular location in the foam core depend on the moisture concentration at that location. Sequentially coupled analyses of moisture diffusion and deformation are performed to predict overall performance of the studied viscoelastic sandwich systems. A time and moisture dependent constitutive model is used for the polymer foam core. A time-integration algorithm is developed to link this constitutive model to finite element (FE) analyses framework. The overall time-dependent responses of the sandwich composites subject to moisture diffusion are analyzed using 2D plane strain and 3D continuum elements. A 23% increase in the transverse deformation of the viscoelastic sandwich beam is observed due to the moisture degradation. Experimental data and analytical models available in the literature are used to verify the results obtained from the FE code. Parametric studies on the effects of different diffusivity ratios of skin and core materials on stress, strain and displacement fields have been analyzed. At the initial times the effect of moisture on the field variables is found to be most pronounced in the case with the highest diffusivity ratio. Contributions of moisture dependent elastic and the time-dependent moduli to the overall stress, strain and displacement field have been studied. The structural analysis of the sandwich composite under combined moisture diffusion and mechanical loading for two kinds of problems using FE method is performed to complete the study.

Download or read book Finite Element Analysis of Structures with Constrained Viscoelastic Layer Damping written by Yung Chen and published by . This book was released on 1990 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Analysis of Anisotropic Viscoelastic Composite Structures and Analytical Determination of Optimum Viscoelastic Material Properties written by Sung Yi and published by . This book was released on 1992 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quasi-static linear anisotropic viscoelastic responses of composite structures subjected to mechanical and hygrothermal loads are formulated in terms of finite element algorithms. Laplace and/or Fourier transforms rather than direct time integrations are used in this formulation in order to improve accuracy and to save extensive computational time and storage. The present quasi-static viscoelastic analyses require the same computer memory as is needed for corresponding elastic eigenvalue problems. Bending and stretching of composite plates for which analytical solutions exist are examined in order to evaluate the accuracy and effectiveness of the present approach. The time dependent displacement fields in the transverse direction for the cross ply and angle ply laminates are calculated and the stacking sequence effects of the laminates are discussed in detail. Creep responses for GY70/339 composite laminates with or without a circular hole are also studied. The numerical results compare favorably with analytical solutions, i.e. within 1.8% for bending and 10$sp{-3}$% for tension. Numerical procedures for analyzing dynamic responses of composite structures with time, temperature and moisture dependent linear viscoelastic damping also have been developed in the time domain using variational principles and the Newmark average acceleration method. Recursion formulas have been formulated in order to reduce computer storage and only the previous time solution is required to compute the next time solution. Verification studies were conducted to evaluate the accuracy and convergence of the present numerical algorithm and they show that the numerical solutions agree well with the analytical ones. As examples, the dynamic transient responses of long cantilevered T300/934 composite Euler beams subjected to unit step and impulse loads were calculated using the presently developed procedures. By using generalized Maxwell models, expressions for stored and dissipated energies in anisotropic viscoelastic bodies are derived. The relaxation modulus curves are analytically generated for parameters such as the initial modulus, the fully relaxed equilibrium modulus, the slope of the transition region and the time span of the relaxation. The influences of relaxation modulus shapes and parameters on stored and dissipated energies under specific loads are then analyzed. By using the present finite element methods, the dynamic transient response of cantilever beams with free damping layers on both sides is calculated in order to evaluate performance of free layer damping treatments.

Download or read book Viscoelastic Analysis of Sandwich Beams Having Aluminum and Fiber reinforced Polymer Skins with a Polystyrene Foam Core written by Altramese Lashé Roberts-Tompkins and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sandwich beams are composite systems having high stiffness-to-weight and strength-to-weight ratios and are used as light weight load bearing components. The use of thin, strong skin sheets adhered to thicker, lightweight core materials has allowed industry to build strong, stiff, light, and durable structures. Due to the use of viscoelastic polymer constituents, sandwich beams can exhibit time-dependent behavior. This study examines and predicts the time-dependent behavior of sandwich beams driven by the viscoelastic foam core. Governing equations of the deformation of viscoelastic materials are often represented in differential form or hereditary integral form. A single integral constitutive equation is used to model linear viscoelastic materials by means of the Boltzmann superposition principle. Based on the strength of materials approach, the analytical solution for the deformation in a viscoelastic sandwich beam is determined based on the application of the Correspondence Principle and Laplace transform. Finite element (FE) method is used to analyze the overall transient responses of the sandwich systems subject to a concentrated point load at the midspan of the beam. A 2D plane strain element is used to generate meshes of the three-point bending beam. User material (UMAT) subroutine in ABAQUS FE code is utilized to incorporate the viscoelastic constitutive model for the foam core. Analytical models and experimental data available in the literature are used to verify the results obtained from the FE analysis. The stress, strain, and deformation fields during creep responses are analyzed. Parameters such as the viscosity of the foam core, the ratio of the skin and core thicknesses, the ratio of the skin and core moduli, and adhesive layers are varied and their effect on the timedependent behavior of the sandwich system is examined.

Download or read book Vibration and Thermal Analysis and Optimum Design of Viscoelastic Sandwich Beam written by Jasrobin Singh Grewal and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Insights and Innovations in Structural Engineering Mechanics and Computation written by Alphose Zingoni and published by CRC Press. This book was released on 2016-11-25 with total page 3395 pages. Available in PDF, EPUB and Kindle. Book excerpt: Insights and Innovations in Structural Engineering, Mechanics and Computation comprises 360 papers that were presented at the Sixth International Conference on Structural Engineering, Mechanics and Computation (SEMC 2016, Cape Town, South Africa, 5-7 September 2016). The papers reflect the broad scope of the SEMC conferences, and cover a wide range of engineering structures (buildings, bridges, towers, roofs, foundations, offshore structures, tunnels, dams, vessels, vehicles and machinery) and engineering materials (steel, aluminium, concrete, masonry, timber, glass, polymers, composites, laminates, smart materials). Some contributions present the latest insights and new understanding on (i) the mechanics of structures and systems (dynamics, vibration, seismic response, instability, buckling, soil-structure interaction), and (ii) the mechanics of materials and fluids (elasticity, plasticity, fluid-structure interaction, flow through porous media, biomechanics, fracture, fatigue, bond, creep, shrinkage). Other contributions report on (iii) recent advances in computational modelling and testing (numerical simulations, finite-element modeling, experimental testing), and (iv) developments and innovations in structural engineering (planning, analysis, design, construction, assembly, maintenance, repair and retrofitting of structures). Insights and Innovations in Structural Engineering, Mechanics and Computation is particularly of interest to civil, structural, mechanical, marine and aerospace engineers. Researchers, developers, practitioners and academics in these disciplines will find the content useful. Short versions of the papers, intended to be concise but self-contained summaries of the full papers, are collected in the book, while the full versions of the papers are on the accompanying CD.

Download or read book Experimental and Numerical Estimation Of written by Angelo De Faenza and published by Angelo De Fenza. This book was released on 2012 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Finite Element Analysis of Foldcores for Sandwich Structures written by Ehsan Nabiyouni and published by . This book was released on 2013 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sandwich structures are used in many different industries. A sandwich panel is made of a light weight core sandwiched amongst two thin skins. The combination of light weight and desired mechanical properties makes sandwich panels ideal for aerospace and automotive industries. The core is typically made of cellular geometries or foams with a high second moment of inertia and thus a high stiffness in bending. Foldcore geometries provide some advantages, such as the less complex and faster manufacturing process, to overcome issues of regular cores used in sandwich panels. These benefits have made this type of core a preferred geometry in the sandwich structures. The most popular pattern used as a foldcore is called Chevron which can be changed to Modified Chevron as well. In this study another foldcore, called Waterbomb is proposed. The main objective of this study was to investigate feasibility of using auxetic foldcores for sandwich structures, and to develop a method whereby the effective mechanical properties of folded patterns, as possible candidates for sandwich structures, can be modeled using finite element analysis. These auxetic foldcores are of interest because they offer curved sandwich panels which can be used in manufacturing dome shape structures in a continuous process without any need to attach several flat sandwich panels. The study was done based on the properties of Aramet papers manufactured by Aramid, Ltd [42]. The mechanical properties needed for the linear elastic analysis were Young's modulus, density and Poisson's ratio. Values of density were provided by the manufacturer and a value of 0.3 was reasonable to be used as the Poisson's ratio for Aramid. The compressive modulus of each paper type was experimentally found. A total of 225 simulations were done, and the results showed different behaviors of the geometries under the compressive loads in z, x and y directions as well as shear loads in x and y directions. Comparisons based on geometry and loading were performed, and presented in tables and figures, thus, one can pick a geometry which is more suitable for their applications.

Download or read book Advancements in Materials Processing Technology Volume 1 written by Rina Sahu and published by Springer Nature. This book was released on with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Composite Structures written by I.H. Marshall and published by Springer. This book was released on 1991-09-30 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers contained herein were presented at the Sixth International Conference on Composite Structures (ICCS/6) held at Paisley College, Scotland in September 1991. The Conference was organised and sponsored by Paisley College. It was co-sponsored by Scottish Enterprise, the National Engineering Laboratory, 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/1/2/3/4 and 5 held at Paisley in 1981, 1983, 1985, 1987 and 1989 respectively. As we enter the final decade of this century many organisations throughout the world are adopting a prophetic role by attempting to forecast future scientific advances and their associated impact on mankind. Although some would argue that to do so is folly, without such futuristic visionaries the world would be that much poorer. IntelJigent speculation based on research trends and historical advances, rather than fanciful theories, breathes a healthy air of enthusiasm into the scientific community. Surely this is the very oxygen necessary to ignite the fir~s of innovation and invention amongst pioneers of research.

Download or read book Mechanics of Sandwich Structures written by A. Vautrin and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 441 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main advantages of sandwiches as structural components are now well known and well-established. Due to the progress in polymer science and engineering and advances in manufacturing processes, sandwich structures can blend various functional and structural properties and therefore lead to highly innovating systems. The current difficulty to overcome is to provide designers with proper methodologies and tools that could enable them to design improved sandwich structures. Such dedicated design tools should be efficient, reliable, flexible and user-friendly. They should be based on advanced knowledge of sandwich behaviour at global and local scales. Such approach relies on our capability to test, identify, control and model structure performances. The impressive variety of core and face materials and the rapid developments in forming processes give new opportunities to design components which have more complex shapes and higher integrated functional and structural properties. Interest in sandwiches is permanently growing in industry and refined testing and modelling approaches should be encouraged to set up relevant guidelines to design reliable advanced structures. The European Society for Mechanics sponsored the EUROMECH 360 Colloquium on the 'Mechanics of Sandwich Structures' in Saint-Etienne, France, on 13 - 15 May 1997. The main purpose of EUROMECH 360 was to go into the most recent progresses in sandwich analysis and design, including mechanical modelling and testing. It was expected that the Colloquium should contribute to define new research directions to support development of advanced applications in strategic industrial sectors such as ground transportations or building and civil engineering.

Download or read book Emerging Trends in Mechanical Engineering written by L. Vijayaraghavan and published by Springer Nature. This book was released on 2019-12-11 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises select proceedings of the International Conference on Emerging Trends in Mechanical Engineering (ICETME 2018). The book covers various topics of mechanical engineering like computational fluid dynamics, heat transfer, machine dynamics, tribology, and composite materials. In addition, relevant studies in the allied fields of manufacturing, industrial and production engineering are also covered. The applications of latest tools and techniques in the context of mechanical engineering problems are discussed in this book. The contents of this book will be useful for students, researchers as well as industry professionals.

Download or read book ICCS19 19th International Conference on Composite Structures written by Antonio J.M. Ferreira and published by Società Editrice Esculapio. This book was released on 2016-08-01 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, it is quite easy to see various applications of fibrous composites, functionally graded materials, laminated composite, nano-structured reinforcement, morphing composites, in many engineering fields, such as aerospace, mechanical, naval and civil engineering. The increase in the use of composite structures in different engineering practices justify the present international meeting where researches from every part of the globe can share and discuss the recent advancements regarding the use of standard structural components within advanced applications such as buckling, vibrations, repair, reinforcements, concrete, composite laminated materials and more recent metamaterials. For this reason, the establishment of this 19th edition of International Conference on Composite Structures has appeared appropriate to continue what has been begun during the previous editions. ICCS wants to be an occasion for many researchers from each part of the globe to meet and discuss about the recent advancements regarding the use of composite structures, sandwich panels, nanotechnology, bio-composites, delamination and fracture, experimental methods, manufacturing and other countless topics that have filled many sessions during this conference. As a proof of this event, which has taken place in Porto (Portugal), selected plenary and keynote lectures have been collected in the present book.