Download or read book Aeroelastic Tailoring with Composites Applied to Forward Swept Wings written by T. J. Hertz and published by . This book was released on 1981 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of aeroelastic tailoring with advanced composites has made forward swept wings a viable configuration option for high performance aircraft. Forward swept wings have an inherent tendency to encounter a static aeroelastic instability called divergence. The extreme weight penalty required to avoid this instability in conventional metallic construction has been the basis for the reluctance of designers to incorporate forward sweep in aircraft. Studies performed for the Flight Dynamics Laboratory and by others independently show that, through the use of aeroelastic tailoring (the design process that makes use of the directional properties of fibrous composite materials in wing skins and orients these materials in optimum directions) with advanced composite material, the aeroelastic behavior of a conventional aft swept wing can be controlled and forward swept wings can be constructed with composites that results in an increase in the divergence speed without a prohibitive increase in weight. This report presents the background and evolution of aeroelastic tailoring as applied to forward swept wings together with a summary of work required to establish an aeroelastic data base for forward swept design.

Download or read book A Demonstration of the Principle of Aeroelastic Tailoring Applied to Forward Swept Wings written by Van C. Sherrer and published by . This book was released on 1982 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: The principle of aeroelastic tailoring with advanced composite materials to increase the divergence speed of a forward swept wing has been demonstrated through low speed wind tunnel tests. The approach was to perform a low cost, fairly simple wind tunnel test on a variable sweep cantilever wing model. Available analytical methods were used and were shown to accurately predict the divergence speed of both aluminum and composite plate structures in the subsonic speed range. Methods were evaluated for predicting the onset of divergence using subcritical wind tunnel data. Results of the analyses and tests are presented.

Download or read book The Aerodynamic Analysis and Aeroelastic Tailoring of a Forward Swept Wing written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of forward-swept wings has aerodynamic benefits at high angles of attack and in supersonic regimes. These consist of reduction in wave drag, profile drag, and increased high angle of attack handling qualities. These increased benefits are often offset due to an increase in structural components, to overcome flutter and wing tip divergence due to high loading of the wing tips at high angles of attack. The use of composite materials and aeroelastic tailoring of the structures eliminates these instabilities without a significant increase in weight. This work presents the design of an aeroelastic wing structure for a highly forward-swept wing, and the verification of the aerodynamic and structural finite element analysis through experimental testing.

Download or read book Aeroelastic Stability and Performance Characteristics of Aircraft with Advanced Composite Sweptforward Wing Structures written by Terrence A. Weisshaar and published by . This book was released on 1978 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sweptforward metallic wings have not been considered to be a serious design concept for nearly thirty years. The large structural weights necessary to preclude aeroelastic divergence of metallic wing structures are unfavorable when compared to similar sweptback designs, designs that are usually divergence free. The development of fibrous laminated composite materials and the fact that forward swept wings may have superior aerodynamic performance has led to renewed interest in this design. In this report, laminated beam theory, together with aerodynamic strip theory, is used to predict the static aeroelastic divergence characteristics of swept wings. From the results of this theory, it is predicted that, because of elastic coupling between bending and torsional deformation of the wing box, laminated composites may be used to preclude wing divergence for a large range of wing forward sweep angles. Formulas are developed to illustrate the important parameters governing composite wing divergence. Two examples are presented to illustrate the use of these formulas. These examples show that composite forward swept wings have the potential to be feasible, efficient designs.

Download or read book Influence of Pylon Airloads and Composite Tailoring on Aeroelastic Stability of a Forward Swept Wing written by Jason C. Slaby and published by . This book was released on 2010 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeroelastic Tailoring of a Forward Swept Wing and Comparisons with Three Equivalent Aft Swept Wings written by William E. Triplett and published by . This book was released on 1980 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Commercial Aircraft Composite Technology written by Ulf Paul Breuer and published by Springer. This book was released on 2016-05-10 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is based on lectures held at the faculty of mechanical engineering at the Technical University of Kaiserslautern. The focus is on the central theme of societies overall aircraft requirements to specific material requirements and highlights the most important advantages and challenges of carbon fiber reinforced plastics (CFRP) compared to conventional materials. As it is fundamental to decide on the right material at the right place early on the main activities and milestones of the development and certification process and the systematic of defining clear requirements are discussed. The process of material qualification - verifying material requirements is explained in detail. All state-of-the-art composite manufacturing technologies are described, including changes and complemented by examples, and their improvement potential for future applications is discussed. Tangible case studies of high lift and wing structures emphasize the specific advantages and challenges of composite technology. Finally, latest R&D results are discussed, providing possible future solutions for key challenges such as low cost high performance materials, electrical function integration and morphing structures.

Download or read book Aeroelastic Behavior of Forward Swept Graphite epoxy Wing Aircraft with Rigid Body Freedoms written by Gun-Shing Chen and published by . This book was released on 1986 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical and experimental investigation was made of the aeroelastic flutter and divergence behavior of a forward swept graphite/epoxy wing aircraft in free flight. Because of the inherent "aeroelastic destiffening" of a forward swept wing and the "aerodynamic stiffening" of the aircraft short period mode, an aeroelastic/flight dynamic interaction becomes possible which can modify the aeroelastic behavior of cantilever wings. A transient aeroelastic analysis, using Rayleigh-Ritz formulation, modified strip theory and measured aircraft aerodynamic derivatives, was developed to predict and interpret the aeroelastic behavior and instability mechanism. The transient aerodynamic representation was obtained by approximating the Theodorsen function in the Laplace domain. With the augmented state variables, stability of the aeroelastic system was determined by linear eigenvalue analysis. A generic, full-span, 30° forward swept wing aircraft model allowing both rigid body pitch and plunge was constructed and tested at MIT's low speed wind tunnel. The effect of aeroelastic tailoring was demonstrated by wings made of different ply layups, namely, [02/90]s' , [152/0]s' , [302/0]s', and [-152/0]s'. These symmetric but unbalanced specimens were chosen to spin a wide range of bending-twisting coupling. Wind tunnel tests on the softly restrained "free flying" models revealed a so-called body freedom flutter, bending-torsion wing flutter, and a tunnel support related dynamic instability which could be eliminated by proper adjustment of the support stiffness. Good agreement with linear theory was found for all the observed instabilities and transient responses. The body freedom flutter boundary was compared with the cantilever wing divergence boundary, and was shown to follow the same aeroelastic tailoring trends, but to be more critical than the wing divergence. Additional tests on the model with rigid body pitch only resulted in a lower body freedom flutter speed, and thereby gave a conservative flutter boundary. The model with [152/0]a wing demonstrated the best tailored aeroelastic behavior for all wings tested.

Download or read book The Aerodynamic Analysis and Aeroelastic Tailoring of a Forward swept Wing written by David William Roberts and published by . This book was released on 2006 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: Aeroelastic, Forward-Swept, Divergence.

Download or read book Fibrous Composites in Structural Design written by Edward M. Lenoe and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 858 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Fourth Conference on Fibrous Composites in Structural Design was a successor to the First-to-Third Conferences on Fibrous Composites in Flight Vehicle Design sponsored by the Air Force (First and Second Conferences, September 1973 and May 1974) and by NASA (Third Conference, November 1975) which were aimed at focusing national attention on flight vehicle applications of a new class of fiber reinforced materials, the advanced com posites, which afforded weight savings and other advantages which had not been previously available. The Fourth Conference, held at San Diego, California, 14-17 November 1978, was the fi rst of these conferences to be jointly sponsored by the Army, Navy and Ai r Force together with NASA, as well as being the first to give attention to non-aerospace applications of fiber reinforced composites. While the design technology for aerospace applications has reached a state of relative maturity, other areas of application such as mi litary bridging, flywheel energy storage systems, ship and surface vessel components and ground vehicle components are in an early stage of development, and it was an important objective to pinpoint where careful attention to structural design was needed in such applications to achfeve maximum structural performance payoff together with a high level of reliability and attractive economics.

Download or read book Thin Walled Composite Beams written by Liviu Librescu and published by Springer Science & Business Media. This book was released on 2006-01-15 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation This is the first monograph devoted to the foundation of the theory of composite anisotropic thin-walled beams and to its applications in various problems involving the aeronautical/aerospace, helicopter, naval and mechanical structures. Throughout the theoretical part, an effort was made to provide the treatment of the subject by using the equations of the 3-D elasticity theory. Non-classical effects such as transverse shear, warping constraint, anisotropy of constituent materials yielding the coupling of twist-bending (lateral), bending (transversal)-extension have been included and their implications have been thoroughly analyzed. Thermal effects have been included and in order to be able to circumvent their deleterious effects, functionally graded materials have been considered in their construction. Implications of the application of the tailoring technique and of the active feedback control on free vibration, dynamic response, instability and aeroelasticity of such structures have been amply investigated. Special care was exercised throughout this work to address and validate the adopted solution methodologies and the obtained results against those available in the literature and obtained via numerical or experimental means.

Download or read book On the aeroelastic characteristics of the forward swept wing optimized by aeroelastic tailoring written by and published by . This book was released on 1993 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Introduction to Aircraft Aeroelasticity and Loads written by Jan Robert Wright and published by John Wiley & Sons. This book was released on 2008-02-28 with total page 559 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aeroelastic phenomena arising from the interaction of aerodynamic, elastic and inertia forces, and the loads resulting from flight / ground manoeuvres and gust / turbulence encounters, have a significant influence upon aircraft design. The prediction of aircraft aeroelastic stability, response and loads requires application of a range of interrelated engineering disciplines. This new textbook introduces the foundations of aeroelasticity and loads for the flexible aircraft, providing an understanding of the main concepts involved and relating them to aircraft behaviour and industrial practice. This book includes the use of simplified mathematical models to demonstrate key aeroelastic and loads phenomena including flutter, divergence, control effectiveness and the response and loads resulting from flight / ground manoeuvres and gust / turbulence encounters. It provides an introduction to some up-to-date methodologies for aeroelastics and loads modelling. It lays emphasis on the strong link between aeroelasticity and loads. It also includes provision of MATLAB and SIMULINK programs for the simplified analyses. It offers an overview of typical industrial practice in meeting certification requirements.

Download or read book Wind tunnel Experiments on Divergence of Forward swept Wings written by Rodney H. Ricketts and published by . This book was released on 1980 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Introduction to Structural Dynamics and Aeroelasticity written by Dewey H. Hodges and published by Cambridge University Press. This book was released on 2011-08-22 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text provides an introduction to structural dynamics and aeroelasticity, with an emphasis on conventional aircraft. The primary areas considered are structural dynamics, static aeroelasticity and dynamic aeroelasticity. The structural dynamics material emphasizes vibration, the modal representation and dynamic response. Aeroelastic phenomena discussed include divergence, aileron reversal, airload redistribution, unsteady aerodynamics, flutter and elastic tailoring. More than one hundred illustrations and tables help clarify the text and more than fifty problems enhance student learning. This text meets the need for an up-to-date treatment of structural dynamics and aeroelasticity for advanced undergraduate or beginning graduate aerospace engineering students.

Download or read book Transonic Unsteady Aerodynamics and Aeroelasticity 1987 written by and published by . This book was released on 1989 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: