Temperature Effects on Flutter of a Mach 5 Transport Aircraft Wing

2012 ◽  
Author(s):  
Dries Verstraete ◽  
Gareth A. Vio
Keyword(s):  
High Temperatures ◽  
Structural Design ◽  
Thermal Stresses ◽  
Material Strength ◽  
Aircraft Structure ◽  
Transport Aircraft ◽  
Hypersonic Aircraft ◽  
Structural Rigidity ◽  
Temperature Distributions ◽  
Strength And Stiffness

The high temperatures encountered during flight severely impact the structural design of hypersonic aircraft. They can lead to high thermal stresses and a significant reduction in material strength and stiffness. This reduction in structural rigidity requires innovative structural concepts and a stronger focus on aero-elastic deformations in the design and optimisation of the aircraft structure. This article investigates the effects of high temperatures on the flutter behavior of the wing of the A2 aircraft, a Mach 5 transport aircraft designed as part of the European Commission Framework VI LAPCAT program. The article presents results for various simplified temperature distributions. These temperature distributions were imposed to look at the fundamental trends in the flutter velocity and frequency with both temperature and temperature distribution. The results for the A2 wing are compared with other wing models to identify effects of geometry variations. The analysis shows that the flutter velocity drops by about 20% when a uniform temperature of 500 °C is applied to the wings. When temperature gradients are applied, a drop of 5–10% is found, which is in line with findings in literature.

Development of a Hypersonic Aircraft Design Optimization Tool

2014 ◽  
Vol 553 ◽  
pp. 847-852 ◽  
Author(s):  
Benjamin J. Morrell ◽  
David J. Munk ◽  
Gareth A. Vio ◽  
Dries Verstraete
Keyword(s):  
Structural Design ◽  
Current Practice ◽  
Thermal Stresses ◽  
Aircraft Design ◽  
Material Strength ◽  
Aircraft Structure ◽  
Aerodynamic Loads ◽  
Design And Optimization ◽  
Hypersonic Aircraft ◽  
Strength And Stiffness

The design and optimization of hypersonic aircraft is severely impacted by the high temperatures encountered during flight as they can lead to high thermal stresses and a significant reduction in material strength and stiffness. This reduction in rigidity of the structure requires innovative structural concepts and a stronger focus on aeroelastic deformations in the early design and optimisation of the aircraft structure. This imposes the need for a closer coupling of the aerodynamic and structural design tools than is current practice. The paper presents the development of a multi-disciplinary, closely coupled optimisation suite for hypersonic aircraft. An overview of the setup and structure of the optimization suite is given and the integration between the Tranair solver, used to determine the aerodynamic loads and temperatures, and MSC/NASTRAN, used for the structural sizing and design, will be given.

A Hypersonic Aircraft Optimization Tool with Strong Aerothermoelastic Coupling

2016 ◽  
Vol 846 ◽  
pp. 494-499 ◽  
Author(s):  
David J. Munk ◽  
Gareth A. Vio ◽  
Dries Verstraete
Keyword(s):  
Structural Design ◽  
Thermal Stresses ◽  
Equilibrium Analysis ◽  
Material Strength ◽  
Preliminary Design ◽  
Time Varying ◽  
Design And Optimization ◽  
Hypersonic Aircraft ◽  
Design Cycle ◽  
Strength And Stiffness

The design and optimization of hypersonic aircraft is severely impacted by the high temperatures encountered during flight as they can lead to high thermal stresses and a significant reduction in material strength and stiffness. This reduction in rigidity of the structure requires innovative structural concepts and a stronger focus on aerothermoelastic deformations in the early design and optimization phase of the design cycle. This imposes the need for a closer coupling of the aerodynamic, thermal and structural design tools than is currently in practice. The paper presents a multi-disciplinary, closely coupled optimization suite that is suitable for preliminary design in the hypersonic regime. The time varying temperature distribution is applied through an equilibrium analysis, and is coupled to the aerodynamics through the Tranair® solver. An analysis of the effect that the aerothermodynamic coupling has on the sizing of the aircraft is given, along with the effect of skin buckling. It is shown that the coupling of the aerothermodynamics drives the sizing of the structure and therefore must be considered for hypersonic applications.

Temperature Effect on the Structural Design of a Mach 8 Vehicle

2014 ◽  
Vol 553 ◽  
pp. 249-254
Author(s):  
Nicholas F. Giannelis ◽  
Gareth A. Vio ◽  
Dries Verstraete ◽  
Johan Steelant
Keyword(s):  
Dynamic Response ◽  
Material Properties ◽  
Structural Design ◽  
Structural Strength ◽  
Aircraft Design ◽  
Structural Performance ◽  
Temperature Changes ◽  
Hypersonic Aircraft ◽  
Temperature Distributions ◽  
Compound Effect

Hypersonic aircraft design is a pressing area of research. The motivation to create aircraft that can cross the globe in only a few hours is driving this forward but there are a number of challenges that need to be overcome. One of the principle challenges is the effect that temperature has on the structure. Temperature changes cause heating of the structure as well as changing the material properties of the affected structure. This has a compound effect in that the structures gets geometrically deformed, stiffness is reduced, and this will have an impact on the aerodynamic and structural performance of the vehicle. This article investigates the effect of two different structural concepts: a conventional rib-spar configuration and a pillow tank. A number of different structural options in terms of number of ribs / spars will be investigated. The structure will be optimised based on critical loading conditions. Results for various temperature distributions will be investigated, while looking at change on structural strength, in-flight static deformation and dynamic response. Keywords: Aeroelasticity, Hypersonics, Design.

scholarly journals Conceptual Advanced Transport Aircraft Design Configuration for Sustained Hypersonic Flight

Aerospace ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 91 ◽  
Author(s):  
Can Alkaya ◽  
Ashish Alex Sam ◽  
Apostolos Pesyridis
Keyword(s):  
Aircraft Design ◽  
Combined Cycle ◽  
Cfd Analysis ◽  
Conceptual Approach ◽  
Transport Aircraft ◽  
Hypersonic Flight ◽  
Hypersonic Aircraft ◽  
Conceptual Aircraft Design

The conceptual aircraft design and its integration with a combined cycle engine for hypersonic cruise at Mach 8 is documented in this paper. The paper describes the process taken to develop a hypersonic aircraft from a conceptual approach. The discussion also includes the design and CFD analysis of the integrated combined cycle engine. A final conceptual hypersonic transport aircraft with an integrated combined cycle engine was achieved through this study. According to the analysis carried out, the aircraft is able to take-off and land at the airports it is intended to be used and will be able to generate enough thrust to sustain hypersonic cruise at an altitude of 30 km.

Research of Short-Leg Shear Wall Structure System Function in Multiple Coupled Field

2012 ◽  
Vol 594-597 ◽  
pp. 2464-2469
Author(s):  
Dai Kui
Keyword(s):  
Structural Design ◽  
Shear Walls ◽  
Shear Wall ◽  
Structure Design ◽  
Wall Structure ◽  
Structural System ◽  
Field Coupling ◽  
Structural Rigidity ◽  
Story Drift ◽  
Force Characteristics

Calculation of Short-leg shear walls structural system is a multi-field coupling problem. Through the research and application of short-leg shear wall structure calculation theory, based on the national codes,the short-leg shear wall design principles are established.It is discussed for the reason of the world's first short-leg shear wall structure design formation and development research. According to short-leg shear wall force characteristics, horizonal displacement is divided into destructive story drift and harmless story drift, the formula for calculating the destructive story drift is obtained, using destructive story drift angle parameters and the change of main section height to control the deformation, to control structural rigidity to ensure the structural design rational purpose.

Northumberland Strait bridge: analysis techniques and results

1996 ◽  
Vol 23 (1) ◽  
pp. 86-97 ◽  
Author(s):  
Amin Ghali ◽  
Gamil Tadras ◽  
Paul H. Langohr
Keyword(s):  
Cross Section ◽  
Structural Design ◽  
Major Part ◽  
Thermal Stresses ◽  
Atlantic Coast ◽  
Variable Depth ◽  
Analysis Techniques ◽  
Ice Forces ◽  
Creep And Shrinkage

The Northumberland Strait at the Atlantic coast of Canada will be crossed by a 13 km bridge. The major part of the superstructure will consist of 44 spans, each of length 250 m and a box cross section of variable depth 4.5–14 m. The superstructure, divided into units of maximum length 192 m, will be produced in a yard by segmental casting and multistage prestressing. These units will be assembled at their final position on top of the piers. Each pier is composed of two pieces, also produced in the yard and connected on site by cast in situ concrete. This paper describes selected analysis problems and their solutions employed in the structural design. The analysis problems are concerned with (i) dynamic response to ice forces; (ii) movements of pier footings and stiffness of the subgrade; (iii) variation of stresses and deformations during construction and during the life of the structure, considering the effects of creep and shrinkage of concrete and relaxation of the prestressed steel; and (iv) thermal stresses. Key words: bridges, concrete, creep, prestress relaxation, segmental construction, shrinkage, strait crossing.

Safety CAE Finite Element Calculation for Pressure Cooker of Plateau Field Kitchen Unit

2013 ◽  
Vol 341-342 ◽  
pp. 501-505
Author(s):  
Han Yang ◽  
Lu Hui Wang ◽  
Ying Ze Wang ◽  
Xiang Hong Zhang ◽  
Xue Qiang Liu
Keyword(s):  
Structural Design ◽  
Small Scale ◽  
Manufacturing Cost ◽  
Element Calculation ◽  
Working Pressure ◽  
Cooking Process ◽  
Modeling Analysis ◽  
Safety And Reliability ◽  
Speed Up ◽  
Strength And Stiffness

The core equipment of plateau field kitchen unit is pressure cooker for staple food, the safety and reliability of which are the key of this project, and therefore, mechanics modeling analysis is carried out. The working theory of pressure cooker is to increase the boiling point of water by enhancing the pressure inside the cooker, so as to speed up the cooking process. In fact, the pressure cooker is a small-scale pressure container when using, normally its working pressure reaches some tens and hundreds Kpa. People pay more attention to its safety and dependability. The traditional way to increase the bearing capacity of container is usually to thicken the wall of container, by doing so, not only the manufacturing cost is increased, but also the weight, thus it is inconvenience in using and bringing. Therefore, in order to make optimum structural design of pressure cooker, reliable analysis on mechanical strength and stiffness are carried out.

Analysis of the Thermal Stress and Strain on Arrigo Fiammingo’s Artistic Window in the Cathedral of Perugia

2001 ◽  
Vol 123 (6) ◽  
pp. 1173-1180 ◽  
Author(s):  
Cinzia Buratti
Keyword(s):  
Thermal Stress ◽  
Thermal Stresses ◽  
Actual State ◽  
Stress And Strain ◽  
Work Of Art ◽  
Temperature Distributions ◽  
Software Program ◽  
Thermal Stress And Strain

Thermal stress can damage fragile materials such as glass. It is a worrisome problem if the glass is a work of art, such as the polychromatic window of Arrigo Fiammingo (1565), in the Cathedral of Perugia, the topic of this paper. The window surface, irradiated by sunlight, suffers different thermal stresses, according to the color of the glass elements. In the present paper a calculation of stresses and strains on the window is carried out, for different temperature distributions due to sunlight, by using the ANSYS 5.3 software program. Results are compared with the actual state of the fissures on the window.

Structural Design for the Development of the Floating Type Photovoltaic Energy Generation System

2010 ◽  
Vol 654-656 ◽  
pp. 2803-2806 ◽  
Author(s):  
Hoon Choi ◽  
Hyung Joong Joo ◽  
Jeong Hun Nam ◽  
Kyoung Soo Kim ◽  
Soon Jong Yoon
Keyword(s):  
Structural Design ◽  
Energy Generation ◽  
Structural Members ◽  
Generation System ◽  
Element Analysis ◽  
Photovoltaic Energy ◽  
Specific Strength ◽  
Strength And Stiffness ◽  
Floating Type ◽  
Structural Behaviors

In this paper, we present the structural design for the development of the floating type photovoltaic energy generation system using pultruded FRP members. Pultruded FRP has superior material properties compared with those of conventional structural materials. Especially, pultruded FRP has an excellent corrosion-resistance along with high specific strength and stiffness, which are highly appreciated for the design and fabrication of the floating type photovoltaic energy generation system. In the paper, investigations pertaining to the mechanical and structural behaviors of FRP structural members based on the experiments are discussed. In addition to the experimental investigation, finite element analysis of the floating type photovoltaic energy generation system composed of pultruded FRP structural shapes has been performed. Finally, we have designed and developed the floating type photovoltaic energy generation system using the results of investigations.

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