OPTIMIZATION OF VARIABLE STIFFNESS CURVED COMPOSITE PANELS UTILIZING NURBS REFERENCE PATHS

Download
2022-5-10
Çimen, Kaan
Variable stiffness composite structure concept has been studied since 1972; however, this concept is stepped into a new age after the automated fiber placement manufacturing machines are started to be used in industry. This study presents an optimization method for three-dimensional (3D) variable stiffness composite structures. The main contribution of the current study is the definition of the reference lay-up path by Non-Uniform Rational B Splines (NURBS) in 3D. The methodology is based on defining a reference path by NURBS and optimizing the NURBS parameters by using the Particle Swarm Optimization (PSO) method to minimize the total strain energy and maximize buckling load of the 3D curved composite panel utilizing unconstrained and constrained optimization. The results show that the reference lay-up path defined by NURBS is successfully optimized such that the total strain energy and the buckling load of the final design are minimized.

Suggestions

Application of fully implicit coupled method for 2D incompressible flows on unstructured grids
Zengin, Şeyda; Tarman, Işık Hakan; Department of Engineering Sciences (2012)
In the subject of Computational Fluid Dynamics (CFD), there seems to be small number of important progress in the pressure-based methods for several decades. Recent studies on the implicit coupled algorithms for pressure-based methods have brought a new insight. This method seems to provide a huge reduction in the solution times over segregated methods. Fully implicit coupled algorithm for pressure-based methods is very new subject with only few papers in literature. One of the most important work in this a...
Mathematical Modeling of Turbulent Flows of Newtonian Fluids in a Concentric Annulus with Pipe Rotation
SORGUN, MEHMET; Aydın, İsmail; ÖZBAYOĞLU, Evren; SCHUBERT, J J (2012-03-01)
In this study, a mathematical model is proposed to predict flow characteristics of Newtonian fluids inside a concentric horizontal annulus. A numerical solution, including pipe rotation, is developed for calculating frictional head losses in concentric annuli for turbulent flow. Navier-Stokes equations are numerically solved using the finite differences technique to obtain the velocity field. Experiments with water are performed in a concentric annulus with and without pipe rotation. Average fluid velocitie...
Nonlinear 3D Modeling and Vibration Analysis of Horizontal Drum Type Washing Machines
Baykal, Cem; Ciğeroğlu, Ender; Yazıcıoğlu, Yiğit (2020-01-01)
In this study, a nonlinear 3-D mathematical model for horizontal drum type washing machines is developed considering rotating unbalance type excitation. Nonlinear differential equations of motion are converted into a set of nonlinear algebraic equations by using Harmonic Balance Method (HBM). The resulting nonlinear algebraic equations are solved by using Newton’s method with arc-length continuation. Several case studies are performed in order to observe the effects of orientation angles of springs and damp...
Fluid-structure interactions with both structural and fluid nonlinearities
Bendiksen, O. O.; Seber, G. (Elsevier BV, 2008-08-19)
In this study, we consider a class of nonlinear aeroelastic stability problems, where geometric nonlinearities arising from large deflections and rotations in the structure interact with aerodynamic nonlinearities caused by moving shocks. Examples include transonic panel flutter and flutter of transonic wings of high aspect ratio, where the presence of both structural and aerodynamic nonlinearities can have a dramatic qualitative as well as quantitative effect on the flutter behavior. Both cases represent i...
Evaluation of mechanical properties of Bi12SiO20 sillenite using first principles and nanoindentation
Isik, M.; Sürücü, Gökhan; Gencer, A.; Hasanlı, Nızamı (2021-08-01)
The mechanical and anisotropic elastic properties of Bi12SiO20 (BSO) were investigated using density functional theory (DFT) calculations and nanoindentation. The calculated and experimentally observed XRD patterns of the compound were reported and the crystal structure of the BSO was determined to be cubic with the lattice constant of a = 1.025 nm. The second-order elastic constants and related polycrystalline elastic moduli (e.g. shear modulus, Young's modulus, Poisson's ratio, linear compressibility and ...
Citation Formats
K. Çimen, “OPTIMIZATION OF VARIABLE STIFFNESS CURVED COMPOSITE PANELS UTILIZING NURBS REFERENCE PATHS,” M.S. - Master of Science, Middle East Technical University, 2022.