ASTROS - A multidisciplinary automated structural design tool

Neill, D. J.

doi:10.2514/3.45976

Cited by 115 publications

(33 citation statements)

References 5 publications

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“…The order of complete-aircraft models for stress and aeroelastic analyses is typically 3000 to 30000 degrees of freedom. Adequate solutions for this problem size are standard features of common finite-element codes [5,29].…”

Section: Generation Of Baseline Modesmentioning

confidence: 99%

“…The common approach to the formulation of dynamic aeroelastic equations [3,4] is the modal approach where the structural displacements are represented by a limited set of low-frequency natural vibration modes. Commonly used structural analysis and optimization schemes such as ASTROS [5] and NASTRAN [6] use the modal approach in the dynamic response and stability disciplines, but the static aeroelastic and stress disciplines are treated by the discrete approach with typically large-order finite-element models with thousands of degrees of freedom. The computational costs associated with the repeated construction of the full discrete finite-element models when the structure changes during the design process, and the associated large-order analyses degrade the usefulness of automated aeroelastic design schemes, especially in the preliminary design stages when extensive trade-off studies for various design concepts are needed.…”

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confidence: 99%

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Procedures and Models for Aeroservoelastic Analysis and Design

Karpel

2001

Z. angew. Math. Mech.

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The multi‐disciplinary area that deals with the interaction of the structural, aerodynamic, and control systems of flight vehicles is called aeroservoelasticity. The various aircraft design aspects which are affected by aeroservoelastic interaction are presented with a common modal‐based formulation. The disciplinary and interaction techniques are reviewed and combined for an integrated design optimization scheme where stress, static‐aeroelastic, closed‐loop flutter, control margins, time response, and continuous gust constraints are treated with a common basic model. The structure is represented in the basic model by a set of low‐frequency normal modes of a baseline design. Design changes are adequately addressed without changing the generalized coordinates. Typical difficulties of the modal approach are alleviated by various optional fictitious‐mass and modal perturbation techniques. Static modes can be added during the optimization process for better convergence to the optimal solution. Minimum‐state rational approximation of the unsteady aerodynamics leads to an efficient state‐space model which can be augmented by any combination of linear control components. Physical weighting algorithm is used to improve the aerodynamic approximations and to select modes for truncation or residualization. Linear reduced‐size models and the associated analytic sensitivities to design changes facilitate extremely efficient and adequately accurate on‐line design sessions. The linear models can be integrated with computational aerodynamics codes for the evaluation of important non‐linear aerodynamic effects early in the design process.

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Section: Generation Of Baseline Modesmentioning

confidence: 99%

mentioning

confidence: 99%

Procedures and Models for Aeroservoelastic Analysis and Design

Karpel

2001

Z. angew. Math. Mech.

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“…Methods for calculating the linear aerodynamic force coef cients, such as the doublet-lattice method (DLM), 1 are well established and integrated into commercial softwares for structuralaeroelastic analysis and design optimization, such as MSC/ NASTRAN 2 and ASTROS. 3 However, these linear models often might be inadequate when used for ight vehicles cruising and maneuvering in the transonic-speed range, where embedded shock waves affect the ow eld signi cantly. For this reason, the static branchof computationalaeroelasticityhasevolved,integratingcomputational uid dynamics (CFD) schemes with various types of structural models.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear Design Loads for Maneuvering Elastic Aircraft

Raveh

Karpel

Yaniv³

2000

Journal of Aircraft

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A computationally ef cient scheme for maneuver load analysis, based on nonlinear aerodynamics, is presented. The kernel of the scheme is a computational uid dynamics (CFD) code for solving the Euler/Navier-Stokes equations for a xed-shape con guration. A modal structural model is used for elastic-shape updates, and a trim corrections algorithm is used for varying the incidences and control surface de ections until the user-de ned maneuver is attained. Computational ef ciency is obtained by performing a few elastic-shape changes and maneuver trim updates, all within the uid dynamics analysis, during the steady-state ow eld convergence. The modal approach, where the structure is represented by a set of its low-frequency vibration modes, greatly simpli es the CFD-structure interface, minimizes the amount of structural data required, and allows simple shape updates of the aerodynamic grid. It is shown that the total computation time required for ow eld convergence for a maneuvering elastic aircraft is typically almost identical to that of the rigid aircraft with given trim variables. The method is demonstrated with a realistic wing-fuselage-elevator transport aircraft model performing symmetric maneuvers at Mach 0.85.

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“…The structural and aerodynamic interface and non-linear trim were automated using the Adaptive Modeling Language (AML) to link ASTROS, NASTRAN and PanAir [22,12,8,16] The authors concluded that geometric nonlinearity is an important design consideration for a joined-wing aircraft and should be included in future models. An effort is currently underway to incorporate this nonlinearity into the design procedure.…”

Section: Capmentioning

confidence: 99%

Structurally Integrated Antennas on a Joined-Wing Aircraft

Smallwood¹

2003

44th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference

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ASTROS - A multidisciplinary automated structural design tool

Cited by 115 publications

References 5 publications

Procedures and Models for Aeroservoelastic Analysis and Design

Procedures and Models for Aeroservoelastic Analysis and Design

Nonlinear Design Loads for Maneuvering Elastic Aircraft

Structurally Integrated Antennas on a Joined-Wing Aircraft

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