Sandwich Structures 7: Advancing with Sandwich

Total Page:16

File Type:pdf, Size:1020Kb

Sandwich Structures 7: Advancing with Sandwich SANDWICH STRUCTURES 7: ADVANCINGWITH SANDWICH STRUCTURES AND MATERIALS Sandwich Structures 7: Advancing with Sandwich Structures and Materials Proceedings of the 7th International Conference on Sandwich Structures, Aalborg University, Aalborg, Denmark, 29-31 August 2005 Edited by O.T. THOMSEN Aalborg University, Aalborg, Denmark E. BOZHEVOLNAYA Aalborg University, Aalborg, Denmark and A. LYCKEGAARD Aalborg University, Aalborg, Denmark A C.I.P. Catalogue record for this book is available from the Library of Congress. ISBN-10 1-4020-3444-X (HB) ISBN-13 978-1-4020-3444-2 (HB) ISBN-10 1-4020-3848-8 (e-book) ISBN-13 978-1-4020-3848-8 (e-book) Published by Springer, P.O. Box 17, 3300 AA Dordrecht, The Netherlands. www.springeronline.com Printed on acid-free paper The cover depicts the ICSS-7 logo, by Kjeld Moseholm and Anders Lyckegaard. © Institute of Mechanical Engineering, Aalborg University, Denmark. Used by permission. All Rights Reserved © 2005 Springer No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording or otherwise, without written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Printed in the Netherlands. TABLE OF CONTENTS Preface xvii KEYNOTE LECTURES Sandwich structures: Past, present, andfuture 3 J.R. Vinson Sandwich structures technology in commercial aviation 13 A.S. Herrmann, P.C. Zahlen and I. Zuardy Damage assessment and damage tolerance of FRP sandwich structures 27 B. Hayman SESSIONSORGANISED BY THE ONR (Office of Naval Research, U.S. Navy, Program Manager Dr. Y. Rajapakse) Mechanics & Analysis Geometrical non-linear response of modern sandwich panels – Localized effects 47 Y. Frostig Global buckling of wide sandwich panels with orthotropic phases: An elasticity solution 57 G.A. Kardomateas Parametric study of structurallygraded core junctions 67 A. Lyckegaard, E. Bozhevolnaya and O.T. Thomsen Local effects induced by core junctions in sandwich beams under general loading conditions 77 E. Bozhevolnaya, A. Lyckegaard and O.T. Thomsen v vi Table of Contents Material characterization of PVC foam under staticanddynamic loading 87 D.C. Loup, R.C. Matteson and A.W.J. Gielen Dynamics Dynamic response of anisotropic sandwich panelstounderwater and in-airexplosions 97 L.Librescu, S.-Y. Oh and J. Hohe Enhancement of blast resistance of sandwich plates 107 G.J. Dvorak and Y.A. Bahei-El-Din Failure, Fracture, Damage and Fatigue A two-propertyyield, failure (fracture) criterion for isotropic matrix materials 117 R.M. Christensen On crack extension in foam cored sandwich fracture specimens 121 R.C. Matteson, L.A. Carlsson, F. Aviles and D.C. Loup Effect of geometric constraint on fracture toughness of PVC foam core sandwichbeams 131 K. Shivakumar, H. Chen and A. Bhargava Damage evaluation of sandwich structures using vibration and thermal signatures 143 A. Cecchini, F. Just-Agosto, D. Serrano and B. Shafiq Fatigue performance and size effects in sandwich composites 153 B. Shafiq, A. Quispitupa, F. Just and M. Banos Study of fatigue endurance of conventional and modified core junctions in sandwich beams 161 E. Bozhevolnaya, A. Lyckegaard and O.T. Thomsen Fatigue of closed cell foams 171 D.Zenkert, A. Shipshaand M. Burman Table of Contents vii Fatigue of pure and nanophased sandwich composites under shear loading 183 H.Mahfuz, S. Zainuddin, M.F. Uddin, V.K. Rangari and S. Jeelani Environmental Degradation Sea water effects on polymeric foams and their sandwichlay-ups 193 Y.J. Weitsman, X. Li and A. Ionita MODELLING, ANALYSIS AND DESIGN Sandwich plates: Stresses, deflection, buckling and wrinkling loads 201 H.-R. Meyer-Piening Modelling of viscoelastically damped sandwich beams: A comparative study 211 H. Hu, S. Belouettar, E. Daya and M. Potier-Ferry A homogenization based theory for laminated and sandwich beams 221 J.S. Hansen, G. Kennedy and S.F.M. de Almeida Modelling of composite and sandwich plates by a trigonometric layerwise theory and multiquadrics 231 C.M.C. Roque, A.J.M. Ferreira and R.M.N. Jorge Stabilitybehaviour of cylindrical and conical sandwich shellswith flexible core 241 C. Zhong and H.-G. Reimerdes High order nonlinear contact effects in the dynamic behavior of delaminated sandwich panels with a flexible core 251 H. Schwarts-Givli, O. Rabinovitch and Y. Frostig Bending behavior of sandwich panels with a “soft” core and embedded rigid inserts 261 O. Rabinovitch and E. Hamed Elastic behaviour of Zreinforced sandwichbeams 271 M. Leite, A. Silva and M. Freitas viii Table of Contents Wrinkling of shallow sandwich shells for the general case of multi-axial orthotropy, curvature andloading 281 V. Skvortsov andO.T. Thomsen Transverse stresses of a filler under multipoint loading of a sandwich panel 291 V.A. Polyakov, R.P. Shlitsa, V.V. Khitrov and V. I. Z higun A triangular finite element for sandwich plates accounting for transverse core compressibility 301 S. Demiray, W. Becker and J. Hohe Finite element for the static and stability analysis of sandwich plates 311 M.Linke, W. Wohlers and H.-G. Reimerdes Two FE formulations for a rapid 3D stress analysis of composite sandwich structures 321 A. Wetzel and L. Kärger Sandwich materials selection charts 331 J. Pflug and I. Verpoest Optimal design of laminated extended & honeycomb cores sandwich panelsunder out-of-plane load with simply supportedboundary conditions usinggeneticalgorithm 341 M.J. Jamali, I. Rajabiand M.H. Kadivar Designing sandwichinserts and core junctions for maximum structural stiffness usingdiscrete material optimization 351 J. Stegmann and E. Lund FRACTURE AND DAMAGE TOLERANCE On residual compressive strength prediction of composite sandwich panels after low-velocity impact damage363 Z. Xie, A.J. Vizzini and M. Yang Investigation of parameters dictating damage and energy adsorption characteristics in sandwich panels 373 G.Zhou, M. Hill and N. Hookham Table of Contents ix Real-time damage detection ofhoneycomb sandwich structures using small-diameter fiber Bragg grating sensors 383 S.Minakuchi, Y. Okabeand N. Takeda The influence offace sheet wrinkle defects on the performance of FRP sandwich structures 393 B.Hayman, C. Berggreen and R. Pettersson Residual strength ofdebonded sandwich panels loaded withlateral pressure 403 P. Jolma, S. Segercrantz and C. Berggreen Measurement of interface fracture toughness of sandwich structures 413 R.C. Østergaard and B.F. Sørensen Numerical study of fractured sandwich composites under flexural loading 423 E.E. Theotokoglou, L.A. Carlsson, C.D. Vrettos and H. Mahfuz Dependence of sandwich damage initiation and crack propagation on core material fracture properties 433 L. Berger, M. Morgenthaler, W. Cantwell, K. Feichtinger and R. Elkin Dependence ofinplane sandwich shear deformation on core material type and thickness 441 M. Morgenthaler, L. Berger, K. Feichtinger and R. Elkin Residual strength of in-plane loaded debonded sandwich panels. Experimental investigation 451 C. Lundsgaard-Larsen, C. Berggreen and A. Nøkkentved Residual strength of in-plane loaded debonded sandwich panels. Fracture mechanical modelling 461 C. Berggreen and B.C. Simonsen Resistance of fastenings of sandwich panels 471 P. H assinen x Table of Contents Experimentalfailure mode determination of GRP/PVC-foam sandwich T-joints 477 A.W.J. Gielen, W. Trouwborst and D.C. Loup Flexuralbehaviour of aluminium foam/composite structures 487 M.Styles, P. Compston and S. Kalyanasundaram Repairclassification for sandwich panelswithhail damage 497 M.Das,E.Madenci and H. Razi Damage tolerance assessment of repaired composite sandwich structures 507 R. Trask, B. Cripps and A. Shenoi DYNAMICS, VIBRATION AND SOUND Dynamical transient response of shallow sandwich panel subjected to pressure field 519 S. Kadyrov and V. Skvortsov Effect of transverse core compressibility on dynamic buckling of sandwich structures 527 J. Hohe, L. Librescu and S.Y. Oh Dynamiccharacterisation of marine sandwich structures 537 M.Battley, I. Stenius, J. Breder and S. Edinger Local free vibration analysis of initially stressed curved sandwich beam 547 W. Wang and R.A. Shenoi Vibration analysis of composite sandwich plates and layup optimization 557 H. Sekine, H. Shirahata and M. Matsuda Flexural vibrations of a three-layer sandwich beam 567 D. Backström and A. Nilsson Aneffective 2D linear elasticity vibrational modelfor layered and sandwich clamped-clamped unidirectional strips 577 S. Karczmarzyk Table of Contents xi Minimization of acoustic radiation from composite sandwich structures 587 H.Denliand J.Q. Sun On wave propagation in sandwich plates under heavy fluid loading 597 S. Sorokin and N. Peake Wave propagation in a sandwich plate loadedbyaviscous compressible fluid 605 A.V. Chubinskiy and S.V. Sorokin IMPACT Impact damageonlightweight sandwich panels 615 D. Zhou and W.J. Stronge Ballistic resistance of 2D & 3D woven sandwich composites 625 A. Shukla, J. Grogan, S.A. Tekalur, A. Bogdanovich and R.A. Coffelt Impact and indentation behavior of sandwich panels 635 C.-J. Lindholm A comparison of low energy impact behaviour in aluminium foam and polymer foam sandwich structures 643 P. Compston, M. Styles and S. Kalyanasundaram Numerical modeling of sandwich panel response to ballistic loading 653 J. Kepler and M.R. Hansen Low velocity impact investigations of sandwich panels with different cores 661 W. Göttner and H.-G. Reimerdes Mechanical behavior of rubber-filled multifunctional honeycomb sandwich composite 671 H.Hao, C.-R. Joe and D.-U. Kim Stitching effect on static and dynamic behaviour of sandwich structures 681 B. Lascoup, Z. Aboura, K. Khellil and M. Benzeggagh xii Table of Contents PROCESSING AND FABRICATION Continuous manufacturing and performance of 3D reinforced sandwich structures 693 G.LeRoy, C. Binetruy and P. Krawczak A novel extrusion-welded sandwich structure for thermoplastic composite storagetanks 703 E. Lagardere, M.-F. Lacrampe, O. Skawinski, P. Krawczak,C.Ducret and M. Giletti The opportunities offlexible foam processing for rigid foam sandwich cores 713 H. Mispreuve and L.
Recommended publications
  • Lightweight Highly Tunable Jamming-Based Composites
    SOFT ROBOTICS Volume 00, Number 00, 2020 ª Mary Ann Liebert, Inc. DOI: 10.1089/soro.2019.0053 Lightweight Highly Tunable Jamming-Based Composites Yashraj S. Narang,1,2 Buse Aktasx,1 Sarah Ornellas,3 Joost J. Vlassak,1 and Robert D. Howe1,4 Abstract Tunable-impedance mechanisms can improve the adaptivity, robustness, and efficiency of a vast array of en- gineering systems and soft robots. In this study, we introduce a tunable-stiffness mechanism called a ‘‘sandwich jamming structure,’’ which fuses the exceptional stiffness range of state-of-the-art laminar jamming structures (also known as layer jamming structures) with the high stiffness-to-mass ratios of classical sandwich com- posites. We experimentally develop sandwich jamming structures with performance-to-mass ratios that are far greater than laminar jamming structures (e.g., a 550-fold increase in stiffness-to-mass ratio), while simulta- neously achieving tunable behavior that standard sandwich composites inherently cannot achieve (e.g., a rapid and reversible 1800-fold increase in stiffness). Through theoretical and computational models, we then show that these ratios can be augmented by several orders of magnitude further, and we provide an optimization routine that allows designers to build the best possible sandwich jamming structures given arbitrary mass, vol- ume, and material constraints. Finally, we demonstrate the utility of sandwich jamming structures by integrating them into a wearable soft robot (i.e., a tunable-stiffness wrist orthosis) that has negligible impact on the user in the off state, but can reduce muscle activation by an average of 41% in the on state.
    [Show full text]
  • Dynamic Responses of Flexible-Link Mechanisms with Passive/Active Damping Treatment Jean-François Deü, Ana Cristina Galucio, Roger Ohayon
    Dynamic responses of flexible-link mechanisms with passive/active damping treatment Jean-François Deü, Ana Cristina Galucio, Roger Ohayon To cite this version: Jean-François Deü, Ana Cristina Galucio, Roger Ohayon. Dynamic responses of flexible-link mech- anisms with passive/active damping treatment. Computers and Structures, Elsevier, 2008, 86 (3-5), pp.258-265. 10.1016/j.compstruc.2007.01.028. hal-01519381 HAL Id: hal-01519381 https://hal.archives-ouvertes.fr/hal-01519381 Submitted on 7 May 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License Dynamic responses of flexible-link mechanisms with passive/active damping treatment J.-F. Deü, A.C. Galucio, R. Ohayon Conservatoire National des Arts et Me´tiers (CNAM), Structural Mechanics and Coupled Systems Laboratory, Case 353, 292 rue Saint Martin, 75141 Paris Cedex 03, France This work presents a finite element formulation for non-linear transient dynamic analysis of adaptive beams. The main contribution of this work concerns the development of an original co-rotational sandwich beam element, which allows large displacements and rota- tions, and takes active/passive damping into account.
    [Show full text]
  • Analysis Methods Used on the NASA Composite Crew Module (CCM)
    Analysis Methods used on the NASA Composite Crew Module (CCM) Craig Collier1, Phil Yarrington2, Mark Pickenheim3 [email protected] Collier Research Corp., Hampton, VA Brett Bednarcyk4 NASA Glenn Research Center, Cleveland, OH Jim Jeans5 Genesis Engineering Solutions, Inc., Lanham, MD The process in use by a national team from NASA research centers and industry partners for the analysis and design of a full scale composite crew module is presented. Methods, failure analyses, and design sizing approaches used by the team are identified. The HyperSizer® software coupled with FEA was used for trade studies of crew module shape configurations, material selections, sandwich panel dimensions, and composite layups and is being used for final analyses and stress report margins-of-safety. Different types of analyses were performed throughout the design maturity and their impacts to the evolving design discussed. These analyses include shell and backbone panel buckling, composite strength to damage tolerance criteria, laminate interlaminar shear, ply drop-offs, sandwich panel specific failures such as facesheet wrinkling, core shear, and core crushing, flat wise tension, core taper ramp downs, and adhesively bonded joints and bolted joints. © 2008 Collier Research Corporation. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. 1, 2, 3 Senior Research Engineers, Hampton, Virginia; AIAA Senior Member, [email protected] 4 Materials Research Engineer, AIAA Senior Member, [email protected] 5 Senior Engineer, [email protected] 1 American Institute of Aeronautics and Astronautics Fig.1, Ares I Crew Launch Vehicle that launches the NASA Crew Module. Fig.2, The Crew Module (CM) interfaces with the Service Module (SM) and the Launch Abort System (LAS).
    [Show full text]
  • Analysis of Sandwich Beam
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by International Journal of Science Engineering and Advance Technology (IJSEAT) International Journal of Science Engineering and Advance ISSN 2321-6905 Technology, IJSEAT, Vol 2, Issue 12 December-2014 Analysis of Sandwich Beam M Siva Prasad#1, P Satish Reddy #2, Matta Manoj #3, N.Guru Murthy #4 ME Department, Prasiddha College of Engg and Technology, Anathavaram 1 [email protected], [email protected], [email protected], [email protected] Abstract- Sandwich beams are composite systems materials. In general, these structures require high having high stiffness-to-weight and Strength-to- reliability assurance for which, the prediction of the weight ratios and are used as light weight load maximum load that the structure can withstand. bearing components. The use of thin, strong skin sheets adhered to thicker, lightweight core materials A sandwich structured composite is a special class of has allowed industry to build strong, stiff, light, and composite materials that is fabricated by attaching durable structures. Due to the use of viscoelastic two thin but stiff skins to a light weight but thick polymer constituents, sandwich beams can exhibit core. The core material is normally low strength time-dependent behaviour. This study examines the material, but its higher thickness provided the behaviour of sandwich beams driven by the sandwich composite with high bending stiffness with viscoelastic rubber core. Finite element (FE) method overall low density. Open and closes cell structured is used to analyze the overall transient responses, foams like polyvinylchloride, polyurethane, harmonic responses and the static responses of the polyethylene or polystyrene foams, and honey combs sandwich systems subject to a concentrated point are commonly used core materials.
    [Show full text]
  • Flexural Analysis and Composite Behavior of Precast Concrete Sandwich Panel
    FLEXURAL ANALYSIS AND COMPOSITE BEHAVIOR OF PRECAST CONCRETE SANDWICH PANEL Thesis Submitted to The School of Engineering of the UNIVERSITY OF DAYTON In Partial Fulfillment of the Requirements for The Degree of Master of Science in Civil and Environmental Engineering By Behnam Naji Dayton, Ohio December, 2012 FLEXURAL ANALYSIS AND COMPOSITE BEHAVIOR OF PRECAST CONCRETE SANDWICH PANEL Name: Naji, Behnam APPROVED BY: Elias Toubia, Ph.D. Steven Donaldson, Ph.D. Advisory Committee Chairman Committee Member Assistant Professor Assistant Professor Civil and Environmental Engineering Civil and Environmental Engineering Thomas Whitney, Ph.D. Committee Member Assistant Professor Civil and Environmental Engineering John G. Weber, Ph.D. Tony E. Saliba, Ph.D. Associate Dean Dean, School of Engineering School of Engineering & Wilke Distinguished Professor ii ©Copyright by Behnam Naji All rights reserved 2012 iii ABSTRACT FLEXURAL ANALYSIS AND COMPOSITE BEHAVIOR OF PRECAST CONCRETE SANDWICH PANEL Name: Naji, Behnam University of Dayton Advisor: Dr. Elias Toubia Several experimental studies have shown the effect of core shear contribution in precast concrete sandwich wall panels. Due to the complex nature of such construction, quantifying the contribution of the core on the behavior of the precast concrete sandwich wall panel subjected to lateral load and in-plane loads is still a challenge. Based on engineering judgment and experience, current design practices assume a certain percentage in composite action between the faces (wythes) of the sandwich panel. In this study, a general equation for the deflection of a simply supported sandwich panel under in-plane and lateral loads was developed. The formulated equation includes all mechanical properties of the core and the thick similar faces.
    [Show full text]
  • A Simple and Accurate Sandwich Plate Theory Accounting for Transverse Normal Strain and Interfacial Stress Continuity ⇑ X
    Composite Structures 107 (2014) 620–628 Contents lists available at ScienceDirect Composite Structures journal homepage: www.elsevier.com/locate/compstruct A simple and accurate sandwich plate theory accounting for transverse normal strain and interfacial stress continuity ⇑ X. Wang, G. Shi Department of Mechanics, Tianjin University, Tianjin 300072, China article info abstract Article history: This paper presents a simple and accurate sandwich plate theory accounting for the transverse normal Available online 2 September 2013 strain and interfacial stress continuity. A refined cubic polynomial is used for the transverse shear func- tion and a linear function is adopted for the transverse normal strain. The Heaviside step function and Keywords: stress continuity coefficients are employed respectively to enforce the interfacial continuity of the in- Sandwich plate theory plane displacements and transverse stresses. By the enforcement of the traction conditions on the plate Transverse shear function surfaces, there are only five independent field variables in the present sandwich plate theory. The varia- Transverse normal strain tional consistent equilibrium equations and boundary conditions in terms of both displacements and Interfacial stress continuity stress resultants are derived by utilizing the variational principle. The analytical solutions of the bending Analytical solution analyses of sandwich plates with different aspect ratios and stiffness ratios are solved to demonstrate the accuracy of this new sandwich plate theory. The resulting analytical solutions of deflections, normal stresses and transverse shear stresses are compared with the 3D elasticity solutions, the numerical results and the results given by other sandwich plate theories. The comparison study shows that this equivalent single layer sandwich plate theory is not only simple, but also capable of achieving the accu- racy of layerwise sandwich plate theories.
    [Show full text]
  • Diab Guideline to Core and Sandwich
    Guideline to Core and Sandwich Introduction to sandwich This document has been written to spread knowledge about sandwich and understanding of its behavior. 1.1 Why sandwich? It has long been known that by separating two materials below). This distinction, along with many other drivers with a lightweight material in between it will increase the such as the environmental benefits, extreme cost savings, structure’s stiffness and strength at very low weight and and freedom of design, are causing sandwich to become cost (see further explanation in “The sandwich principle” more and more popular in structural design. 1.1.1 Weight benefits One of the most driving reasons to use sandwich is that solution enables faster and smaller robots. Within the concept enables lightweight construction. The energy- theatre, it enables fast set changes between scenes. In saving benefits are described in the previous section, construction, a bridge or façade facilitates fast, effective but it also enables faster and more effective solutions in installation. In transportation, lower weight in containers many cases. Sports equipment is one segment for which or vessel construction enables higher payloads. Clearly, strength and speed are important. Another is racing, such the benefits of lightweight solutions go on and on. as sailing, speed boats etc. In industry, a lightweight 1.1.2 Environmental benefits Obviously, anything that moves consumes energy, and environmental impact of material choice in the beginning the heavier it is, the more energy consumed. Since using (energy) and in the end (recycling) of a vessel’s life cycle sandwich makes structural designs lighter, sandwich is minor (as long as the material choice saves weight) in solutions are extremely environmentally friendly.
    [Show full text]
  • Free Vibration of Flexible Soft-Core Sandwiches According to Layerwise Theories Differently Accounting for the Transverse Normal Deformability
    ORIGINAL ARTICLE Free Vibration of flexible soft-core sandwiches according to layerwise theories differently accounting for the transverse normal deformability Ugo Icardia* Andrea Urracia a Dipartimento di Ingegneria Meccanica e Aerospaziale - Politecnico di Torino - Corso Duca degli Abruzzi 24, 10129 Torino, Italy. E-mail: [email protected], [email protected] * Corresponding author https://doi.org/10.1590/1679-78255624 Abstract This study aims to generalize a previously developed accurate and inexpensive 3-D zig-zag theory up to an arbitrary representation form and to determine which simplifications are yet accurate in determining transverse shear and normal stress/deformation effects on vibrations of soft-core sandwiches with not moving middle/neutral plane (pumping). Natural frequencies are calculated using displacements assumed differently across the thickness, having fixed d.o.f., not yet explored forms of representation and zig-zag functions differently accounting for the transverse normal deformability and that partially or fully fulfill physical constraints. Applications are presented for sandwich plates and beams with length-to-thickness ratios and material properties of faces and core varying within an industrial range, for which layerwise effects are very important and so suited to the evaluation of theories. Analytical solutions are found using the same trial functions and expansion order for all theories, so to evaluate their accuracy under the same conditions. The choice of the representation form and of zig-zag functions is shown immaterial if displacement field coefficients are recomputed across the thickness by enforcing the fulfillment of all physical constraints (using symbolic calculus). Furthermore, it is shown that assigning a specific role to each coefficient is immaterial, as well as exchanging the order of representation of in-plane and transverse displacement components and even that zig-zag functions could be omitted.
    [Show full text]
  • Stress Analysis of Tapered Sandwich Panels with Isotropic Or Laminated Composite Facings Huyue Zhao
    The University of Maine DigitalCommons@UMaine Electronic Theses and Dissertations Fogler Library 2002 Stress Analysis of Tapered Sandwich Panels with Isotropic or Laminated Composite Facings Huyue Zhao Follow this and additional works at: http://digitalcommons.library.umaine.edu/etd Part of the Mechanical Engineering Commons Recommended Citation Zhao, Huyue, "Stress Analysis of Tapered Sandwich Panels with Isotropic or Laminated Composite Facings" (2002). Electronic Theses and Dissertations. 309. http://digitalcommons.library.umaine.edu/etd/309 This Open-Access Thesis is brought to you for free and open access by DigitalCommons@UMaine. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of DigitalCommons@UMaine. STRESS ANALYSIS OF TAPERED SANDWICH PANELS WITH ISOTROPIC OR LAMINATED COMPOSITE FACINGS I BY Huyue Zhao B.S. Huazhong University of Science and Technology, 1996 M.S. Huazhong University of Science and Technology, 2000 A THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science (in Mechanical Engineering) The Graduate School The University of Maine December, 2002 Advisory Committee: Senthil Vel, Assistant Professor of Mechanical Engineering, Co-Advisor Vincent Caccese, Associate Professor of Mechanical Engineering, Co-Advisor Donald A. Grant, RC. Hill Professor of Mechanical Engineering Michael "Mick" Peterson, Assistant Professor of Mechanical Engineering LIBRARY RIGHTS STATEMENT I In presenting this thesis in partial hlfillment of the requirements for an advanced degree at The University of Maine, I agree that the Library shall make it freely available for inspection. I hrther agree that permission for "fair use" copying of this thesis for scholarly purposes may be granted by the Librarian.
    [Show full text]
  • Carbon Foam Characterization
    CARBON FOAM CHARACTERIZATION: SANDWICH FLEXURE, TENSILE AND SHEAR RESPONSE A Thesis by MELANIE DIANE SARZYNSKI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 2003 Major Subject: Mechanical Engineering CARBON FOAM CHARACTERIZATION: SANDWICH FLEXURE, TENSILE AND SHEAR RESPONSE A Thesis by MELANIE DIANE SARZYNSKI Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved as to style and content by: _________________________________ _________________________________ Ozden Ochoa Paul Roschke (Chair of Committee) (Member) _________________________________ _________________________________ Harry Hogan Dennis O’Neal (Member) (Head of Department) _________________________________ William Schneider (Member) December 2003 Major Subject: Mechanical Engineering iii ABSTRACT Carbon Foam Characterization: Sandwich Flexure, Tensile and Shear Response. (December 2003) Melanie Diane Sarzynski, B.S., Texas A&M University Chair of Advisory Committee: Dr. Ozden Ochoa The focus of this research is characterizing a new material system composed of carbon and graphite foams, which has potential in a wide variety of applications encompassing aerospace, military, offshore, power production and other commercial industries. The benefits of this new material include low cost, light weight, fire-resistance, good energy absorption, and thermal insulation or conduction as desired. The objective of this research is to explore the bulk material properties and failure modes of the carbon foam through experimental and computational analysis in order to provide a better understanding and assessment of the material for successful design in future applications. Experiments are conducted according to ASTM standards to determine the mechanical properties and failure modes of the carbon foam.
    [Show full text]
  • Creep Behaviour of Geometrically Nonlinear Soft Core Sandwich Panels
    20th International Conference on Composite Materials Copenhagen, 19-24th July 2015 CREEP BEHAVIOUR OF GEOMETRICALLY NONLINEAR SOFT CORE SANDWICH PANELS Ehab Hamed1 and Yeoshua Frostig2 1Centre for Infrastructure Engineering and Safety, School of Civil and Environmental Engineering, University of New South Wales, NSW 2052, Sydney, Australia Email: [email protected], web page: http://www.unsw.edu.au 2Faculty of Civil and Environmental Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel. Email: [email protected], web page: http://www.technion.ac.il Keywords: Buckling, Creep, High-order, Sandwich panels, Viscoelasticity. ABSTRACT This paper investigates the effects of creep of the core material on the global geometrically nonlinear behavior of sandwich panels under axial and lateral loading conditions. The theoretical model combines the concepts of the hereditary (convolution) integral of viscoelasticity based on the principle of superposition, with the high-order sandwich theory. From the expansion of the relaxation moduli into Prony series, an incremental exponential law that corresponds to the rheological generalized Maxwell model is obtained, and which allows for a step-by-step time analysis that accounts for the change in deformations and stresses with time. The results show that creep of the core can lead to a significant reduction in the global buckling capacity of sandwich panels. 1 INTRODUCTION Sandwich panels that are made of metallic or laminated composite face sheets and a soft core find a wide spread use in many engineering applications. Under service conditions, sandwich panels can be subjected to different load scenarios, one of them being axial compression that is combined with lateral loading/effects due to imperfections, self-weight, and other effects.
    [Show full text]
  • Effect of Core Material Stiffness on Sandwich Panel Behavior Beyond the Yield Limit
    Proceedings of the World Congress on Engineering 2010 Vol II WCE 2010, June 30 - July 2, 2010, London, U.K. Effect of Core Material Stiffness on Sandwich Panel Behavior Beyond the Yield Limit Salih N. Akour1, Hussein Z. Maaitah2 Abstract—Sandwich panels attracted designer's interest due skins to produce a lightweight panel with exceptional to its light weight, excellent corrosion characteristics and rapid stiffness as shown in Fig. 1. The face skins act like the installation capabilities. Sandwich panels have been flanges of an I-beam to provide resistance to the separating implemented in many industrial applications such as face skins and carrying the shear forces. The faces are aerospace, marine, architectural and transportation industry. Sandwich panels consist of two face sheets and core. The core typically bonded to the core to achieve the composite action is usually made of material softer than the face sheets. Most of and to transfer the forces between the components. the previous work deals with sandwich panel in the elastic Work on the theoretical description of sandwich structure range. However the current investigation unveils the effect of behavior began after World War Two. Reference [1] is the the core material stiffness on sandwich panel beyond the yield first book published about sandwich structures, followed by limit of core material. The modulus of elasticity ratio of the [2] and more recently [3]. Reference [4] developed a method core (Foam) to face (sheet metal) is investigated by applying univariate search optimization technique. The load has been to design for minimum weight, and reported the failure increased in steps in quasi–static manner till face sheets reach mode map of sandwich construction, without considering the yield point.
    [Show full text]