Supply chain management is the set of tasks through which businesses acquire, process, and move raw materials and final products from suppliers through factories and distribution points to customers. The mathematical problems encountered in supply chain optimization models are difficult to solve. Free Trade Agreements can simplify the models of inter-company trade between countries. Another way to make these models more tractable is to decompose the complete supply chain into a set of small, manageable units representing businesses or business processes and optimize the system by controlling the interactions between these units. We illustrate such a model and optimize it with genetic-algorithm-controlled Multidisciplinary Design Optimization

Throughout the evolution of rotorcraft design, great advancements have been made in developing performance analysis and sizing tools to assist designers during the preliminary and detailed design phases. However, very few tools exist to assist designers during the conceptual design phase. Most performance analysis tools are very discipline or concept specific, and many are far too cumbersome to use for comparing vastly different concepts in a timely manner. Consequently, many conceptual decisions must be made qualitatively. A need exists to develop a single software tool which is capable of modeling any type of feasible rotorcraft concept using different levels of detail and accuracy in order to assist in the decision making throughout the conceptual and preliminary design phases. This software should have a very intuitive and configurable user interface which allows users of different backgrounds and experience levels to use it, while providing a broad capability of modeling traditional, innovative, and highly complex design concepts. As an illustration, a newly developed Concept Independent Rotorcraft Analysis and Design Software (CIRADS) will be presented to prove the applicability of such software tools. CIRADS is an object oriented application with a Graphical User Interface (GUI) for specifying mission requirements, aircraft configurations, weight component breakdowns, engine performance, and airfoil characteristics. Input files from the GUI are assembled to form analysis and design project files which are processed using algorithms developed in MATLAB but compiled as a stand alone executable and imbedded in the GUI. The performance calculations are based primarily upon a modified momentum theory with empirical correction factors and simplified blade stall models. The ratio of fuel (RF) sizing methodology is used to size the aircraft based on the mission requirements specified by the user. The results of the analysis/design simulations are then displayed in tables and Text Fields in the GUI. The intent for CIRADS is to become a primary conceptual sizing and performance estimation tool for the Georgia Institute of Technology rotorcraft design teams for use in the annual American Helicopter Society Rotorcraft Design Competition.

The Multidisciplinary Design Optimization (MDO) system is needed to reduce the developing time and production cost in most industries. The MDO is the new technology for optimization design, and considers solid mechanics, dynamics, kinematics, vibration/noise control, and fluid mechanics, simultaneously. Higher product quality, less developing time and lower manufacturing cost will be achieved through a balanced and organic MDO method. In this paper, numerical stress analysis, optimization method, and experimental stress analysis will be conducted to accomplish: 1) production cost; 2) developing time; 3) quality improvement; and 4) service-rate drop. First, the coupled analysis using the finite element method will be performed to obtain the accurate data. Second, OPTISTRUCT, which is commercial optimization software, will be used for shape and size optimization analysis. Third, an experimental stress analysis system will be established to assist the optimization design and numerical analysis.

No description available.

A multidisciplinary design optimization framework is developed that integrates control system design with aerostructural design for a highly-deformable wing. The objective of this framework is to surpass the existing aircraft endurance limits through the use of an active load alleviation system designed concurrently with the rest of the aircraft. The novelty of this work is two fold. First, a unified dynamics framework is developed to represent the full six-degree-of-freedom rigid-body along with the structural dynamics. It allows for an integrated control design to account for both manoeuvrability (flying quality) and aeroelasticity criteria simultaneously. Secondly, by synthesizing the aircraft control system along with the structural sizing and aerodynamic shape design, the final design has the potential to exploit synergies among the three disciplines and yield higher performing aircraft. A co-rotational structural framework featuring Euler--Bernoulli beam elements is developed to capture the wing's nonlinear deformations under the effect of aerodynamic and inertial loadings. In this work, a three-dimensional aerodynamic panel code, capable of calculating both steady and unsteady loadings is used. Two different control methods, a model predictive controller (MPC) and a 2-DOF mixed-norm robust controller, are considered in this work to control a highly flexible aircraft. Both control techniques offer unique advantages that make them promising for controlling a highly flexible aircraft. The control system works towards executing time-dependent manoeuvres along with performing gust/manoeuvre load alleviation. The developed framework is investigated for demonstration in two design cases: one in which the control system simply worked towards achieving or maintaining a target altitude, and another where the control system is also performing load alleviation. The use of the active load alleviation system results in a significant improvement in the aircraft performance relative to the optimum result without load alleviation. The results show that the inclusion of control system discipline along with other disciplines at early stages of aircraft design improves aircraft performance. It is also shown that structural stresses due to gust excitations can be better controlled by the use of active structural control systems which can improve the fatigue life of the structure.

Automatic Implementation of Multidisciplinary Design Optimization Architectures Using piMDO Christopher Marriage Masters of Applied Science Graduate Department of Aerospace Engineering University of Toronto 2008 Multidisciplinary Design Optimization (MDO) provides optimal solutions to complex, coupled, multidisciplinary problems. MDO seeks to manage the interactions between disciplinary simulations to produce an optimum, and feasible, design with a minimum of computational effort. Many MDO architectures and approaches have been developed, but usually in isolated situations with little chance for comparison. piMDO was developed to provide a unified framework for the solution of coupled op- timization problems and refinement of MDO approaches. The initial implementation of piMDO showed the benefits of a modular, object oriented, approach and laid the groundwork for future development of MDO architectures. This research furthered the development of piMDO by expanding the suite of available problems, incorporat- ing additional MDO architectures, and extending the object oriented approach to all of the required components for MDO. The end result is a modular, flexible software framework which is user friendly and intuitive to the practitioner. It allows complex problems to be quickly implemented and optimized with a variety of powerful numerical tools and MDO architectures. Importantly, it allows any of its components to be reorganized and sets the stage for future researchers to continue the development of MDO methods.

A multidisciplinary design optimization framework is developed that integrates control system design with aerostructural design for a highly-deformable wing. The objective of this framework is to surpass the existing aircraft endurance limits through the use of an active load alleviation system designed concurrently with the rest of the aircraft. The novelty of this work is two fold. First, a unified dynamics framework is developed to represent the full six-degree-of-freedom rigid-body along with the structural dynamics. It allows for an integrated control design to account for both manoeuvrability (flying quality) and aeroelasticity criteria simultaneously. Secondly, by synthesizing the aircraft control system along with the structural sizing and aerodynamic shape design, the final design has the potential to exploit synergies among the three disciplines and yield higher performing aircraft. A co-rotational structural framework featuring Euler--Bernoulli beam elements is developed to capture the wing's nonlinear deformations under the effect of aerodynamic and inertial loadings. In this work, a three-dimensional aerodynamic panel code, capable of calculating both steady and unsteady loadings is used. Two different control methods, a model predictive controller (MPC) and a 2-DOF mixed-norm robust controller, are considered in this work to control a highly flexible aircraft. Both control techniques offer unique advantages that make them promising for controlling a highly flexible aircraft. The control system works towards executing time-dependent manoeuvres along with performing gust/manoeuvre load alleviation. The developed framework is investigated for demonstration in two design cases: one in which the control system simply worked towards achieving or maintaining a target altitude, and another where the control system is also performing load alleviation. The use of the active load alleviation system results in a significant improvement in the aircraft performance relative to the optimum result without load alleviation. The results show that the inclusion of control system discipline along with other disciplines at early stages of aircraft design improves aircraft performance. It is also shown that structural stresses due to gust excitations can be better controlled by the use of active structural control systems which can improve the fatigue life of the structure.

Automatic Implementation of Multidisciplinary Design Optimization Architectures Using piMDO Christopher Marriage Masters of Applied Science Graduate Department of Aerospace Engineering University of Toronto 2008 Multidisciplinary Design Optimization (MDO) provides optimal solutions to complex, coupled, multidisciplinary problems. MDO seeks to manage the interactions between disciplinary simulations to produce an optimum, and feasible, design with a minimum of computational effort. Many MDO architectures and approaches have been developed, but usually in isolated situations with little chance for comparison. piMDO was developed to provide a unified framework for the solution of coupled op- timization problems and refinement of MDO approaches. The initial implementation of piMDO showed the benefits of a modular, object oriented, approach and laid the groundwork for future development of MDO architectures. This research furthered the development of piMDO by expanding the suite of available problems, incorporat- ing additional MDO architectures, and extending the object oriented approach to all of the required components for MDO. The end result is a modular, flexible software framework which is user friendly and intuitive to the practitioner. It allows complex problems to be quickly implemented and optimized with a variety of powerful numerical tools and MDO architectures. Importantly, it allows any of its components to be reorganized and sets the stage for future researchers to continue the development of MDO methods.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 209-213). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 209-213). Also available on the Internet.