Semi analytical study of stress and deformation analysis of anisotropic shells of revolution including first order transverse shear deformation

Download

index.pdf

Date

2008

Author

Oygür, Özgür Sinan

Metadata

Show full item record

Item Usage Stats

226
views

196
downloads

In this study, anisotropic shells of revolution subject to symmetric and unsymmetrical static loads are analysed. In derivation of governing equations to be used in the solution, first order transverse shear effects are included in the formulation. The governing equations can be listed as kinematic equations, constitutive equations, and equations of motion. The equations of motion are derived from Hamilton’s principle, the constitutive equations are developed under the assumptions of the classical lamination theory and the kinematic equations are based on the Reissner-Naghdi linear shell theory. In the solution method, these governing equations are manipulated and written as a set called fundamental set of equations. In order to handle anisotropy and first order transverse shear deformations, the fundamental set of equations is transformed into 20 first order ordinary differential equations using finite exponential Fourier decomposition and then solved with multisegment method of integration, after reduction of the two-point boundary value problem to a series of initial value problems. The results are compared with finite element analysis results for a number of sample cases and good agreement is found. Case studies are performed for circular cylindrical shell and truncated spherical shell geometries. While reviewing the results, effects of temperature and pressure loads, both constant and variable throughout the shell, are discussed. Some drawbacks of the first order transverse shear deformation theory are exhibited.

Subject Keywords

Aerospace engineering., Aeronautical Engineering.

URI

http://etd.lib.metu.edu.tr/upload/2/12609870/index.pdf
https://hdl.handle.net/11511/18219

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Experimental and numerical investigation of flow field around flapping airfoils making figure-of-eight in hover Başkan, Özge; Alemdaroğlu, Hüseyin Nafiz; Department of Aerospace Engineering (2009) The aim of this study is to investigate the flow field around a flapping airfoil making figure-of-eight motion in hover and to compare these results with those of linear flapping motion. Aerodynamic characteristics of these two-dimensional flapping motions are analyzed in incompressible, laminar flow at very low Reynolds numbers regime using both the numerical (Computational Fluid Dynamics, CFD) and the experimental (Particle Image Velocimetry, PIV) tools. Numerical analyses are performed to investigate the...
Nonlinear flutter calculations using finite elements in a direct Eulerian-Lagrangian formulation Seber, Guclu; Bendiksen, Oddvar O. (American Institute of Aeronautics and Astronautics (AIAA), 2008-06-01) A fully nonlinear aeroelastic formulation of the direct Eulerian-Lagrangian computational scheme is presented in which both structural and aerodynamic nonlinearities are treated without approximations. The method is direct in the sense that the calculations are done at the finite element level, both in the fluid and structural domains, and the fluid-structure system is time-marched as a single dynamic system using a multistage Runge-Kutta scheme. The exact nonlinear boundary condition at the fluid-structure...
Time-domain calculation of sound propagation in lined ducts with sheared flows Özyörük, Yusuf (American Institute of Aeronautics and Astronautics (AIAA), 2000-05-01) A recent application of the time-domain equivalent of the classical acoustic impedance condition, i.e., the particle displacement continuity equation, to numerical simulations of a Bow-impedance tube in the time domain yielded reasonably good results with uniform mean flows. The present paper extends this application to include sheared mean-flow effects on sound propagation over acoustically treated walls. To assess the prediction improvements with sheared flows, especially at relatively high Mach numbers, ...
Structural optimization strategies via different optimization and solver codes and aerospace applications Ekren, Mustafa; Kayran, Altan; Department of Aerospace Engineering (2008) In this thesis, structural optimization study is performed by using three different methods. In the first method, optimization is performed using MSC.NASTRAN Optimization Module, a commercial structural analysis program. In the second method, optimization is performed using the optimization code prepared in MATLAB and MSC.NASTRAN as the solver. As the third method, optimization is performed by using the optimization code prepared in MATLAB and analytical equations as the solver. All three methods provide ce...
Accuracy and efficiency improvements in finite difference sensitivity calculations Özhamam, Murat; Eyi, Sinan; Department of Aerospace Engineering (2007) Accuracy of the finite difference sensitivity calculations are improved by calculating the optimum finite difference interval sizes. In an aerodynamic inverse design algorithm, a compressor cascade geometry is perturbed by shape functions and finite differences sensitivity derivatives of the flow variables are calculated with respect to the base geometry flow variables. Sensitivity derivatives are used in an optimization code and a new airfoil is designed verifying given design characteristics. Accurate sen...

Citation Formats

Ö. S. Oygür, “Semi analytical study of stress and deformation analysis of anisotropic shells of revolution including first order transverse shear deformation,” M.S. - Master of Science, Middle East Technical University, 2008.