Technical ReportPDF Available

Buckling analysis of a strut and design of a fuselage section for a high altitude aerospace vehicle - Airframe Design Coursework

February 2015

DOI:10.13140/RG.2.2.29105.79201

Authors:

Sergiu Petre Iliev

Imperial College London

This is a two part paper addressing the AirFrame Design coursework problems. The first part presents the buckling analysis of an aluminium alloy unlipped channel section. Following the linear static and buckling analysis of a strut with spans ranging from 0.2m to 4m with two constraint configurations to maintain a simply supported condition, it was possible to determine its buckling failure modes in Creo Simulate 3.0. These results proved to be consistent with both analytical and empirical (ESDU) solutions. This paper presents the correlation of these means of analysis with the purpose of establishing the limitations and degree of applicability of the model to real cases. The second part presents the design of a ‘double bubble’ fuselage section under loading conditions specific to high altitude aerospace vehicles. The complete design process of the skin-stringers configuration at one fuselage station is presented analytically and an algorithm is developed to automate this process. Furthermore, the report discusses the advantages, limitations and assumptions made in using CFRP as a material when compared to Hiduminium in the design of the fuselage section.

Content uploaded by Sergiu Petre Iliev

Content may be subject to copyright.





λ

Graphical comparison of numerical and analytical data with ESDU













 

 

 

   





 

 

 

 











 















 



































ResearchGate has not been able to resolve any citations for this publication.

ResearchGate has not been able to resolve any references for this publication.

Article

Stability analysis of steel cable-stayed bridges

January 2001 · STRUCTURAL ENGINEERING AND MECHANICS

The objective of this study is to investigate the stability behavior of steel cable-stayed bridges by comparing the buckling loads obtained by means of finite element methods with eigen-solver. In recent days, cable-stayed bridges dramatically attract engineers' attention due to their structural characteristics and aesthetics. They require a number of design parameters and present a high degree ... [Show full abstract] of static indetermination, especially for long span bridges. Cable-stayed bridges exhibit several nonlinear behaviors concurrently under normal design loads due to the individual nonlinearity of substructures such as the pylons, stay cables, and bridge deck, and their interactions. The geometric nonlinearities arise mainly from large displacements of cables. Strong axial and lateral forces acting on the bridge deck and pylons cause structural nonlinear behaviors. The interaction is among the substructures. In this paper, a typical three-span steel cable-stayed bridge with a variety of design parameters has been investigated. The numerical results indicate that the design parameters such as the ratio of L1/L and Ip/Ib are important for the structural behavior, where L1 is the main span length, L is the total span length of the bridge, Ip is the moment of inertia of the pylon, and Ib is the moment of inertia of the bridge deck. When the ratio Ip/Ib increases, the critical load decreases due to the lack of interaction among substractures. Cable arrangements and the height of pylon are another important factors for this type of bridge in buckling analysis. According to numerical results, the bridges supported by a pylon with harp-type cable arrangement have higher critical loads than the bridges supported by a pylon with fan-type cable arrangement. On contrary, the shape of the pylon does not significantly affect the critical load of this type of bridge. All numerical results have been non-dimensionalized and presented in both tabular and graphical forms.

Article

Stress and Buckling Analysis of a Certain Type of All-Composite Landing Gear

February 2013 · Advanced Materials Research

FEA method was conducted to investigate static stress and buckling analysis of a certain all-composite landing gear strut. The critical buckling load and bucking mode shapes of the landing gear is obtained using ANSYS finite element analysis code. The first six buckling mode shapes and static stress distribution are given. According to the analysis results, the dynamic characteristics of the ... [Show full abstract] landing gear are discussed. The analysis method and results in this paper can be used for further study on making maintenance plan and safety verification for the landing gear.

Article

COMPOSITE PRESSURE VESSELS

April 2012 · International Journal of Research in Engineering and Technology

Rao Yarrapragada K.S.S

Cylindrical pressure vessels are widely used for commercial, under water vehicles and in aerospace applications. At present the outer shells of the pressure vessels are made up of conventional metals like steels and aluminum alloys. The payload performance/ speed/ operating range depends upon the weight. The lower the weight the better the performance, one way of reducing the weight is by ... [Show full abstract] reducing the weight of the shell structure. The use of composite materials improves the performance of the vessel and offers a significant amount of material savings. Moreover, the stacking sequence is very crucial to the strength of the composite material. This Project involves various objective functions such as stiffness, buckling load and Weight at each level of optimization. Usually composite pressure vessels are designed for minimum mass under strength constraints. A graphical analysis is presented to find optimum fiber orientation for given layer thicknesses. In the present work, an analytical model is developed for the Prediction of the minimum buckling load with / without stiffener composite shell of continuous angle ply laminas (±45°,±55°,±65°,±75°,±85°) for investigation. Comparisons are made for two different approaches i.e. the finite element model and the theoretical model. A 3-D finite element analysis is built using ANSYS-12.0 version software into consideration, for static and buckling analysis on the pressure vessel.

Research Proposal

Full-text available

COMPOSITE PRESSURE VESSELS

December 2012

Cylindrical pressure vessels are widely used for commercial, under water vehicles and in aerospace applications. At present the outer shells of the pressure vessels are made up of conventional metals like steels and aluminum alloys. The payload performance/ speed/ operating range depends upon the weight. The lower the weight the better the performance, one way of reducing the weight is by ... [Show full abstract] reducing the weight of the shell structure. The use of composite materials improves the performance of the vessel and offers a significant amount of material savings. Moreover, the stacking sequence is very crucial to the strength of the composite material. This Project involves various objective functions such as stiffness, buckling load and Weight at each level of optimization. Usually composite pressure vessels are designed for minimum mass under strength constraints. A graphical analysis is presented to find optimum fiber orientation for given layer thicknesses. In the present work, an analytical model is developed for the Prediction of the minimum buckling load with / without stiffener composite shell of continuous angle ply laminas (±45°,±55°,±65°,±75°,±85°) for investigation. Comparisons are made for two different approaches i.e. the finite element model and the theoretical model. A 3-D finite element analysis is built using ANSYS-12.0 version software into consideration, for static and buckling analysis on the pressure vessel.