The increasing complexity of engineering systems has sparked increasing interest in multidisciplinary optimization (MDO). This paper presents a survey of recent publications in the field of aerospace where interest in MDO has been particularly intense. The two main challenges of MDO are computational expense and organizational complexity. Accordingly the survey is focused on various ways different researchers use to deal with these challenges. The survey is organized by a breakdown of MDO into its conceptual components. Accordingly, the survey includes sections on Mathematical Modeling, Design- oriented Analysis, Approximation Concepts, Optimization Procedures, System Sensitivity, and Human Interface. With the authors'' main expertise being in the structures area, the bulk of the references focus on the interaction of the structures discipline with other disciplines. In particular, two sections at the end focus on two such interactions that have recently been pursued with a particular vigor: Simultaneous Optimization of Structures and Aerodynamics, and Simultaneous Optimization of Structures Combined With Active Control.

/pdf/multidisciplinary-aerospace-design-optimization-survey-of-3xuwvr970l.pdf

Multidisciplinary Aerospace Design Optimization: Survey of Recent Developments

The increasing complexity of engineering systems has sparked increasing interest in multidisciplinary optimization (MDO). This paper presents a survey of recent publications in the field of aerospace where interest in MDO has been particularly intense. The two main challenges of MDO are computational expense and organizational complexity. Accordingly the survey is focussed on various ways different researchers use to deal with these challenges. The survey is organized by a breakdown of MDO into its conceptual components. Accordingly, the survey includes sections on Mathematical Modeling, Design-oriented Analysis, Approximation Concepts, Optimization Procedures, System Sensitivity, and Human Interface. With the authors' main expertise being in the structures area, the bulk of the references focus on the interaction of the structures discipline with other disciplines. In particular, two sections at the end focus on two such interactions that have recently been pursued with a particular vigor: Simultaneous Optimization of Structures and Aerodynamics, and Simultaneous Optimization of Structures Combined With Active Control.

/pdf/multidisciplinary-aerospace-design-optimization-survey-of-ghzjxaiur6.pdf

Multidisciplinary aerospace design optimization: Survey of recent developments

Equilibrium and stability equations of a rectangular plate made of functionally graded material under thermal loads are derived, based on the classical plate theory. When it is assumed that the material properties vary as a power form of thicknesscoordinate variable z and when the variational method is used, the system of fundamental differential equations isestablished. Thederived equilibrium and stability equationsforfunctionally graded plates areidenticalwith theequationsforhomogeneousplates. Bucklinganalysisoffunctionally graded platesunderfour typesofthermalloadsiscarriedoutresultinginclosed-formsolutions.Thebucklingloadsarereducedtothecritical buckling temperature relationsfor functionally graded plates with linearcomposition of constituent materials and homogeneous plates. The results are validated with the reduction of the buckling relations for functionally graded plates to those of isotropic homogeneous plates given in the literature.

Thermal Buckling of Functionally Graded Plates

http://rozup.ir/download/511517/sciencedirect6707ecd6-a448-20150419040005.pdf

Thermal buckling of a simply supported moderately thick rectangular fgm plate

Aeroelasticity is still dynamic, challenging, and a key part of cutting-edge airplane technology. Emerging trends, as well as challenges and needs in the field of airplane aeroelasticity, are surveyed and discussed. The paper complements other overview papers on various aspects of the fixed-wing aeroelastic problem, published recently for the centennial year of flight. It includes an extensive bibliography and emphasizes those aspects of aeroelastic technology development not covered thoroughly elsewhere.

Future of Airplane Aeroelasticity

Topic Collections Related Content Customize your page view by dragging and repositioning the boxes below. Related Journal Articles Filter by Topic > Homogenization of Reticulated Structures Appl. Mech. Rev (July, 2001) Research Advances in the Dynamic Stability Behavior of Plates and Shells: 1987â€“2005â€”Part I: Conservative Systems Appl. Mech. Rev (March, 2007) Historical review of Zig-Zag theories for multilayered plates and shells Appl. Mech. Rev (May, 2003) [+] View More Related Proceedings Articles Filter by Topic > A Combined Experimental-Numerical Method to Evaluate Powder Thermal Properties in Laser Powder Bed Fusion MSEC2018 (2018) A Simplified and Efficient Analysis of Morton Effect GT2018 (2018) Thermal Transport in Thorium Dioxide IMECE2017 (2017) [+] View More Related eBook Content Various Structures Design of Plate and Shell Structures> Chapter 12 Axially Loaded Members Design & Analysis of ASME Boiler and Pressure Vessel Components in the Creep Range> Chapter 2 Members in Bending Design & Analysis of ASME Boiler and Pressure Vessel Components in the Creep Range> Chapter 3 [+] View More Sections PDF Email Share Get Citation Get Alerts Some tools below are only available to our subscribers or users with an online account. SEARCH ADVANCED SEARCH Search Applied Mechanics Applied Mechanics Heat Transfer About ASME Digital Collection Email Alerts Library Service Center ASME Membership Contact Us Publications Permissions /Reprints Privacy Policy Terms of Use © 2019 ASME The American Society of Mechanical Engineers Journals Submit a Paper Announcements Call for Papers Title History Conference Proceedings About ASME Conference Publications Conference Proceedings Author Guidelines Conference Publications Toolbox eBooks About ASME eBooks Press Advisory & Oversight Committee Book Proposal Guidelines This site uses cookies. By continuing to use our website, you are agreeing to our privacy policy. | Accept Loading [Contrib]/a11y/accessibility-menu.js

Thermal Buckling of Plates and Shells

An analytical approach for determining the thermal-structural response of a flexible rolled-up solar array due to a sudden increase in external heating is developed. Two analyses are presented: 1) an uncoupled thermal-structural analysis that assumes the heating and temperature gradients are not affected by thermally induced motions, and 2) a coupled thermal-structural analysis that includes the effects of structural deformations on heating and temperature gradients. The analytical methods identify key parameters for understanding the static and dynamic response. A stability criterion given in nondimensional parameters establishes the conditions for thermal flutter. Key parameters for thermal flutter include the ratio of thermal and structural response times, the solar inclination angle, and the system damping. Numerical calculations are presented for the solar arrays on the Hubble Space Telescope. Unstable oscillations are possible but are unlikely to have practical importance.

Thermally induced bending vibrations of a flexible rolled-up solar array

Since the first supersonic flight in October 1947, the United States has designed, developed and flown flight vehicles within increasingly severe aerothermal environments. Over this period, major advances in engineering capabilities have occurred that will enable the design of thermal structures for high speed flight vehicles in the twenty-first century. Progress in thermal-structures is surveyed for the last four decades to provide a historical perspective for future efforts.

Thermal structures - Four decades of progress

The performance of a significant number of spacecraft has been impacted negatively by attitude disturbances resulting from thermally induced deformations of flexible appendages. Motions of flexible appendages such as deployable booms and solar arrays result in disturbance torques reacting on the main body of a spacecraft and may have a significant effect on the attitude dynamics and control of the vehicle. The effects of thermally induced structural disturbances of a flexible appendage on the attitude dynamics of a simple spacecraft are investigated. The governing equations, including transient thermal effects, are formulated using a generalized form of Lagrange's equations for hybrid coordinate dynamical systems. An approximate solution based on modal expansion is presented for the case of a step change in solar heating that simulates an orbital eclipse transition. Analytical models are presented for the thermal-structural response of two types of flexible appendages: a thin-walled boom with tip mass and a solar panel. Numerical results demonstrate that the attitude response of the system consists of a slowly developing pointing error and superimposed oscillations whose magnitude is related to the ratio of the thermal and structural response times of the flexible appendage.

Thermally Induced Attitude Dynamics of a Spacecraft with a Flexible Appendage

Thermally induced structural motions are known to affect the attitude dynamics of low Earth orbiting satellites during eclipse transitions. Motions of e exible appendages such as solar panels lead to rigid body rotations of the entire satellite because the total angular momentum of the system is conserved. These potentially large attitude disturbances may violate pointing accuracy and jitter requirements. One type of thermally induced dynamics exhibited by solar panels is thermal snap. The Upper Atmosphere Research Satellite is a prominent example of a satellite that experiences thermal snap disturbances during eclipse transitions. This paper describes recent studies of thermally induced dynamicsof solarpanels, including an analysisofsatelliteattitudedynamics resulting from thermally induced structural motions and a laboratory investigation of the thermal-structural performance of a satellite solar panel. Analytical and experimental results demonstrate thermal bending deformations with acceleration transients that have characteristic thermal snap disturbance histories in response to rapid changes in heating. The studies show that solar panel thermal snap disturbances are caused by through-the-thickness temperature differences that vary at a nonconstant rate. Finite element analysis correctly predicts the thermal snap phenomenon observed in the solar panel experiments.

Earl A. Thornton

Papers

Thermal Buckling of Plates and Shells

Thermally induced bending vibrations of a flexible rolled-up solar array

Thermal structures - Four decades of progress

Thermally Induced Attitude Dynamics of a Spacecraft with a Flexible Appendage

Thermally Induced Dynamics of Satellite Solar Panels