Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 19 of 19 for “"Shape Sensitivity"”.
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Shape Sensitivity Analysis and Computer-Aided Design of Nonlinear Structures
A unified approach for explicit structural design sensitivity analysis of linear and non-linear elastic systems is presented. First-order sensitivity expressions involving the complete set of design variables, including shape design parameters, are derived for general response functionals. Both …
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Continuum Analytical Shape Sensitivity Analysis of 1-D Elastic Bar
In this thesis, a continuum sensitivity analysis method is presented for calculation of shape sensitivities of an elastic bar. The governing differential equations and boundary conditions for the elastic bar are differentiated with respect to the shape design parameter to derive the continuum …
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Shape sensitivity analysis of flutter response of a laminated wing
A method is presented for calculating the shape sensitivity of a wing aeroelastic response with respect to changes in geometric shape. Yates’ modified strip method is used in conjunction with Giles' equivalent plate analysis to predict the flutter speed, frequency, and reduced frequency of the …
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Accuracy analysis of the semi-analytical method for shape sensitivity analysis
… method can have serious accuracy problems for shape design variables in structures modeled by beam, plate, truss, frame, and solid elements. Local and global indices are developed to test the accuracy of the semi-analytical method. The local indices provide insight into the problem of large …
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Cálculo de sensibilidades: uma aplicação do método dos elementos de contorno à otimização de forma
This work aims at the development of shape sensitivity analysis with the application of the Boundary Element Method (B.E.M.) and its use in the shape design optimization. A shape sensitivity procedure is developed in wich the standard discretized version of the boundary integral equation is …
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Shape Optimisation for Hydrodynamic Stability and its Application to Cyclone Separators
… eigenvalue problem which gives a series of mode shapes (the eigenfunctions) and their growth rates and frequencies (the eigenvalues). This thesis calculates and interprets the shape sensitivity of the eigenvalue of a global stability analysis. The shape sensitivity allows quick calculation of the …
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Analysis and finite element approximation of an optimal shape control problem for the steady-state Navier-Stokes equations
An optimal shape control problem for the steady-state Navier-Stokes equations is considered from an analytical point of view. We examine a rather specific model problem dealing with 2-dimensional channel flow of incompressible viscous fluid: we wish to determine the shape of a bump on a part of the …
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Local Continuum Sensitivity Method for Shape Design Derivatives Using Spatial Gradient Reconstruction
… of this research is to develop a continuum shape sensitivity method that can support gradient-based design optimization of practical and multidisciplinary high-fidelity analyses. A local continuum sensitivity analysis (CSA) that utilizes spatial gradient reconstruction (SGR) and avoids mesh …
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Continuum Sensitivity Method for Nonlinear Dynamic Aeroelasticity
In this dissertation, a continuum sensitivity method is developed for efficient and accurate computation of design derivatives for nonlinear aeroelastic structures subject to transient<br />aerodynamic loads. The continuum sensitivity equations (CSE) are a set of linear partial<br />differential …
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Integrated Multidisciplinary Design Optimization Using Discrete Sensitivity Analysis for Geometrically Complex Aeroelastic Configurations
… unstructured grid approach to aerodynamic shape sensitivity analysis and design optimization has been developed. The advantage of unstructured grids, when compared with a structured-grid approach, is their inherent ability to discretize irregularly shaped domains with greater efficiency and …
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A computational implementation of design sensitivity analysis and structural optimisation
… effort in computational optimisation. Design Sensitivity Analysis (DSA) crucially underpins much of structural optimisation and, as such, is focussed on more intently than the optimisation theory itself: various approaches to the Direct Differentiation Method (DDM) DSA procedure are …
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The topological derivative and its applications to fracture-based analysis and design
… are calculated using the so-called topological-shape sensitivity method [2]. We next propose an approximation of the energy release rate field in a three-dimensional domain associated with a small surface crack of any boundary location, direction, and orientation combination using the …
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Impact damage behaviour of lightweight materials
… are performed using different projectile nose shapes to span a wide range of stress states at the onset of ductile fracture. Impact perforation behaviour, ballistic limit velocity, energy absorption capability and sensitivity to projectile tip geometry are evaluated. Modes of deformation and …
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Multidisciplinary design of thermally radiating structures using a level set based topology optimization approach
… first contribution of this thesis is deriving a shape sensitivity of the thermal heat power radiated objective function using the adjoint method. This sensitivity is a necessary ingredient for our gradient-based algorithm. The second contribution is developing a topology optimization framework …
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Adjoint-based optimization for inkjet printing
… This problem is approached by obtaining the sensitivity of the total energy inside an inkjet microchannel with respect to boundary forcing using the adjoint method. Using gradient-based optimization algorithms, optimal waveforms are found that minimize the objective value at various final …
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Shape optimization for thermoacoustic instability with an adjoint Helmholtz solver
… SLEPc. We then derive the formulae for the shape derivatives of the eigenvalues of the Helmholtz equation in Hadamard form for different boundary conditions and in the cases of simple and semi-simple degenerate eigenvalues. These formulae allow us to efficiently calculate the effect of …
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Multiscale design of nonlinear materials using a shape optimization scheme based on an interface-enriched GFEM
… particulate composites at the mesoscale using a shape optimization scheme to minimize or maximize a nonlinear cost function at the macroscale while satisfying a set of constraints associated, for example, with the volume fraction of inclusions or with the manufacturing technique. The optimization …
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Isogeometric Design, Analysis and Optimisation of Lattice-Skin Structures
… design of lattice-skin structures, a novel shape interrogation scheme for splines, specifically subdivision surfaces, is proposed, which is able to compute the line/surface intersection efficiently and robustly without resorting to successive refinements or iterations as in Newton-Raphson …
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Dimensionally reduced modeling and gradient-based design of microchannel cooling networks
… and hydraulic models, a numerical solver and a shape optimization scheme. Another goal of this project is to verify and validate the dimensionally reduced models against a commercial computational fluid dynamics software package and experiments. The final goal is to apply the design tool to …