Design for Disassembly With High-Stiffness, Heat-Reversible Locator-Snap Systems

2007 ◽  
Author(s):  
Mohammed Shalaby ◽  
Kazohiro Saitou
Keyword(s):  
Optimization Problem ◽  
Screw Theory ◽  
Design Stage ◽  
Material Recycling ◽  
High Stiffness ◽  
Multi Objective Genetic Algorithm ◽  
Trade Offs ◽  
Maximum Stiffness ◽  
Effective Part ◽  
Alternative Designs

Recent legislative and social pressures have driven manufacturers to consider effective part reuse and material recycling at the end of product life at the design stage. One of the key considerations is to design and use joints that can disengage with minimum labor, part damage, and material contamination. This paper presents a unified method to design high-stiffness reversible locator-snap system that can disengage non-destructively with localized heat, and its application to external product enclosures of electrical appliances. The design problem is posed as an optimization problem to find the orientations, numbers, and locations of locators and snaps, and the number, locations and sizes of heating areas, which realize the release of snaps with minimum heating area and maximum stiffness, while satisfying any motion and structural requirements. Screw Theory is utilized to pre-calculate a set of feasible orientations of locators and snaps, which are examined during optimization. The optimization problem is solved using Multi Objective Genetic Algorithm (MOGA) coupled with structural and thermal FEA. The method is applied to two-piece enclosure of a DVD player with a T-shaped mating line. The resulting Pareto-optimal solutions exhibit alternative designs with different trade-offs between structural stiffness during snap engagement and area of heating for snap disengagement. Some results require the heating of two areas at the same time, demonstrating the idea of a lock-n-key.

scholarly journals High-Stiffness, Lock-and-Key Heat-Reversible Locator-Snap Systems for the Design for Disassembly

2008 ◽  
Author(s):  
Mohammed Shalaby ◽  
Kazuhiro Saitou
Keyword(s):  
Optimization Problem ◽  
Screw Theory ◽  
Design Stage ◽  
Material Recycling ◽  
High Stiffness ◽  
Multi Objective Genetic Algorithm ◽  
Trade Offs ◽  
Effective Part ◽  
The Right ◽  
Alternative Designs

Recent legislative and social pressures have driven manufacturers to consider effective part reuse and material recycling at the end of product life at the design stage. One of the key considerations is to use joints that can disengage with minimum labor, part damage, and material contamination. This paper extends our previous work on the design of high-stiffness reversible locator-snap system that can disengage non-destructively with localized heat [1, 2], to include 1) modeling for tolerance stack-up and 2) lock-and-key concept to ensure that snaps only disengage when the right procedure is followed. The design problem is posed as an optimization problem to find the locations, numbers, and orientations of locators and snaps, and the number, locations and sizes of heating areas, which realize the release of snaps with minimum heat, compliance, and tolerance stack-up. The motion and structural requirements are considered constraints. Screw Theory is utilized to pre-calculate a set of feasible types and orientations of locators and snaps that are examined during optimization. The optimization problem is solved using Multi Objective Genetic Algorithm (MOGA) coupled with structural and thermal FEA. The method is applied on two case studies. The Pareto-optimal solutions present alternative designs with different trade-offs between the design objectives while meeting all the constraints.

Design for Disassembly With High-Stiffness Heat-Reversible Locator-Snap Systems

2008 ◽  
Vol 130 (12) ◽  
Author(s):  
Mohammed Shalaby ◽  
Kazuhiro Saitou
Keyword(s):  
Optimization Problem ◽  
Screw Theory ◽  
Design Stage ◽  
Element Analysis ◽  
Material Recycling ◽  
High Stiffness ◽  
Multi Objective Genetic Algorithm ◽  
Trade Offs ◽  
Maximum Stiffness ◽  
Effective Part

Recent legislative and social pressures have driven manufacturers to consider effective part reuse and material recycling at the end of product life at the design stage. One of the key considerations is to design and use joints that can disengage with minimum labor, part damage, and material contamination. This paper presents a unified method to design a high-stiffness reversible locator-snap system that can disengage nondestructively with localized heat, and its application to external product enclosures of electrical appliances. The design problem is posed as an optimization problem to find the locations, numbers, and orientations of locators and snaps as well as the number, locations, and sizes of heating areas, which realize the release of snaps with minimum heating area and maximum stiffness while satisfying any motion and structural requirements. The screw theory is utilized to precalculate a set of feasible orientations of locators and snaps, which are examined during optimization. The optimization problem is solved using the multi-objective genetic algorithm coupled with the structural and thermal finite element analysis. The method is applied to a two-piece enclosure of a DVD player with a T-shaped mating line. The resulting Pareto-optimal solutions exhibit alternative designs with different trade-offs between the structural stiffness during snap engagement and the area of heating for snap disengagement. Some results require the heating of two areas at the same time, demonstrating the idea of a lock-and-key.

scholarly journals High-Stiffness, Lock-and-Key Heat-Reversible Locator-Snap Systems for the Design for Disassembly

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Mohammed Shalaby ◽  
Kazuhiro Saitou
Keyword(s):  
Optimization Problem ◽  
Screw Theory ◽  
Design Stage ◽  
Design For Disassembly ◽  
Element Analysis ◽  
Material Recycling ◽  
High Stiffness ◽  
Multi Objective Genetic Algorithm ◽  
Trade Offs ◽  
The Right

Driven by the moral sense of obligation, legislative and social pressures, manufacturers now consider effective part reuse and material recycling at the end of product life at the design stage. It is a key consideration to use joints that can disengage with minimum labor, part damage, and material contamination. This paper extends our previous work on the design of high-stiffness reversible locator-snap system that can disengage nondestructively with localized heat (Shalaby and Saitou, 2006, “Optimal Heat-Reversible Snap Joints for Frame-Panel Assembly in Aluminum Space Frame Automotive Bodies,” Proceedings of the LCE2006: The 13th CIRP International Conference on Life Cycle Engineering, Leuven, Belgium, May 31–Jun. 2, pp. 411–416; Shalaby and Saitou, 2008, “Design for Disassembly With High-Stiffness, Heat-Reversible Locator-Snap Systems,” ASME J. Mech. Des., 130(12), p. 121701) to include (1) modeling for tolerance stack-up and (2) lock-and-key concept to ensure that snaps only disengage when the right procedure is followed. The design problem is posed as an optimization problem to find the locations, numbers, and orientations of locators and snaps, and the locations and sizes of heating areas, to release the snaps with minimum heat, compliance, and tolerance stack-up. The motion and structural requirements are considered constraints. Screw theory is employed to precalculate the set of feasible types and orientations of locators and snaps that are examined during optimization. Multi-objective genetic algorithm coupled with structural and thermal finite element analysis is used to solve the optimization problem. The method is applied on two case studies. The Pareto-optimal solutions present alternative designs with different trade-offs between the design objectives.

scholarly journals Alternative Agri-Food Systems Under a Market Agencements Approach: The Case of Multifunctional Farming Activity in a Peri-Urban Area

Environments ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 61
Author(s):  
Maria Cecilia Mancini ◽  
Filippo Arfini ◽  
Federico Antonioli ◽  
Marianna Guareschi
Keyword(s):  
Urban Area ◽  
Food Systems ◽  
Food System ◽  
Large Body ◽  
Alternative Food ◽  
Design Stage ◽  
Alternative Food Networks ◽  
Alternative Food Systems ◽  
Design And Implementation ◽  
Trade Offs

(1) Background: A large body of literature is available on the environmental, social, and economic sustainability of alternative food systems, but not much of it is devoted to the dynamics underlying their design and implementation, more specifically the processes that make an alternative food system successful or not in terms of its sustainability aims. This gap seems to be particularly critical in studies concerning alternative food systems in urban and peri-urban agriculture (UPA). This paper explores how the design and implementation of multifunctional farming activity in a peri-urban area surrounding the city of Reggio Emilia in the Emilia-Romagna region of Italy impact the achievement of its sustainability aims. (2) Methods: The environmental, social, and economic components of this project are explored in light of the sociology of market agencements. This method brings up the motivations of the human entities involved in the project, the role played by nonhuman entities, and the technical devices used for the fulfillment of the project’s aims. (3) Results: The alternative food system under study lacked a robust design phase and a shared definition of the project aims among all the stakeholders involved. This ended in a substantial mismatch between project aims and consumer expectations. (4) Conclusions: When a comprehensive design stage is neglected, the threefold aim concerning sustainability might not be achievable. In particular, the design of alternative food systems must take into account the social environment where it is intended to be put in place, especially in UPA, where consumers often live in suburban neighborhoods wherein the sense of community is not strong, thus preventing them from getting involved in a community-based project. In such cases, hybridization can play a role in the sustainability of alternative food networks, provided that some trade-offs occur among the different components of sustainability—some components of sustainability will be fully achieved, while others will not.

Workspace, dexterity and dimensional optimization of microhexapod

2015 ◽  
Vol 35 (4) ◽  
pp. 341-347 ◽  
Author(s):  
E. Rouhani ◽  
M. J. Nategh
Keyword(s):  
Degrees Of Freedom ◽  
Optimization Problem ◽  
Screw Theory ◽  
Design Parameters ◽  
Dimensional Synthesis ◽  
Content Type ◽  
Workspace Analysis ◽  
The Difference ◽  
Flexure Joints ◽  
6 Degrees Of Freedom

Purpose – The purpose of this paper is to study the workspace and dexterity of a microhexapod which is a 6-degrees of freedom (DOF) parallel compliant manipulator, and also to investigate its dimensional synthesis to maximize the workspace and the global dexterity index at the same time. Microassembly is so essential in the current industry for manufacturing complicated structures. Most of the micromanipulators suffer from their restricted workspace because of using flexure joints compared to the conventional ones. In addition, the controllability of micromanipulators inside the whole workspace is very vital. Thus, it is very important to select the design parameters in a way that not only maximize the workspace but also its global dexterity index. Design/methodology/approach – Microassembly is so essential in the current industry for manufacturing complicated structures. Most of the micromanipulators suffer from their restricted workspace because of using flexure joints compared to the conventional ones. In addition, the controllability of micromanipulators inside the whole workspace is very vital. Thus, it is very important to select the design parameters in a way that not only maximize the workspace but also its global dexterity index. Findings – It has been shown that the proposed procedure for the workspace calculation can considerably speed the required calculations. The optimization results show that a converged-diverged configuration of pods and an increase in the difference between the moving and the stationary platforms’ radii cause the global dexterity index to increase and the workspace to decrease. Originality/value – The proposed algorithm for the workspace analysis is very important, especially when it is an objective function of an optimization problem based on the search method. In addition, using screw theory can simply construct the homogeneous Jacobian matrix. The proposed methodology can be used for any other micromanipulator.

scholarly journals Multi-Objective Optimization of Autonomous Microgrids with Reliability Consideration

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4466
Author(s):  
Maël Riou ◽  
Florian Dupriez-Robin ◽  
Dominique Grondin ◽  
Christophe Le Loup ◽  
Michel Benne ◽  
...  
Keyword(s):  
Power Systems ◽  
Rural Areas ◽  
Energy System ◽  
Design Stage ◽  
Multi Objective Optimization ◽  
Renewable Energy Resources ◽  
Nsga Ii ◽  
Renewable Integration ◽  
Multi Objective ◽  
Trade Offs

Microgrids operating on renewable energy resources have potential for powering rural areas located far from existing grid infrastructures. These small power systems typically host a hybrid energy system of diverse architecture and size. An effective integration of renewable energies resources requires careful design. Sizing methodologies often lack the consideration for reliability and this aspect is limited to power adequacy. There exists an inherent trade-off between renewable integration, cost, and reliability. To bridge this gap, a sizing methodology has been developed to perform multi-objective optimization, considering the three design objectives mentioned above. This method is based on the non-dominated sorting genetic algorithm (NSGA-II) that returns the set of optimal solutions under all objectives. This method aims to identify the trade-offs between renewable integration, reliability, and cost allowing to choose the adequate architecture and sizing accordingly. As a case study, we consider an autonomous microgrid, currently being installed in a rural area in Mali. The results show that increasing system reliability can be done at the least cost if carried out in the initial design stage.

Development of a Methodology for Determining the Best Option for the Route of the Heat Network at the Initial Design Stage

2021 ◽  
pp. 57-64
Author(s):  
А. А. Чуйкина
Keyword(s):  
Mathematical Model ◽  
Vector Optimization ◽  
Optimization Problem ◽  
Pairwise Comparison ◽  
Design Stage ◽  
Heat Network ◽  
Thermal Network ◽  
Initial Design ◽  
Matrix Generalization ◽  
Joint Application

Постановка задачи. Выбор наилучшего варианта трассы тепловой сети на начальном этапе проектирования является сложной многофакторной задачей, кроме того, ввиду отсутствия ряда необходимых конструктивных расчетов ее решение сопровождается ограниченностью набора исходных данных. Таким образом, становится актуальной разработка новой методики проектирования оптимальной трассы системы теплоснабжения, учитывающей качественные и количественные характеристики рассматриваемого объекта. Результаты. Разработана математическая модель обобщенного аддитивного векторного критерия оптимальности, учитывающая материалоемкость тепловой сети, ее надежность, время строительства, годовые тепловые потери, оборот теплоты и дисперсию температуры у потребителя. Предложен способ определения наилучшего варианта трассы тепловой сети на начальном этапе проектирования путем совместного решения задачи оптимизации методами векторной оптимизации и матричного обобщения. Отмечена целесообразность совместного применения методов попарного сравнения и векторной оптимизации при решении рассматриваемой задачи. Выводы. Важной характеристикой разработанной математической модели обобщенного критерия является возможность получения более точного решения рассматриваемой оптимизационной задачи при неравномерным распределении тепловой нагрузки посредством смещенной оценки дисперсии температуры у потребителей. Совместное применение методов матричного обобщения, попарного сравнения и векторной оптимизации позволяет повысить точность расчета при решении оптимизационной задачи выбора наилучшей трассы тепловой сети. Statement of the problem. Choosing the best option for the route of the thermal network at the initial stage of design is a complex multifactorial task, in addition, due to the lack of a number of necessary design calculations, its solution is accompanied by a limited set of initial data. Thus, it becomes relevant to develop a new methodology for designing the optimal route of the heat supply system, taking into account the qualitative and quantitative characteristics of the object under consideration. Results. A mathematical model of a generalized additive vector optimality criterion has been developed, taking into account the material consumption of the heat network, its reliability, construction time, annual thermal losses, heat turnover and temperature dispersion at the consumer. A method is proposed for determining the best option for the route of a thermal network at the initial design stage by jointly solving the optimization problem using vector optimization and matrix generalization methods. The expediency of the joint application of the methods of pairwise comparison and vector optimization in solving the problem under consideration is noted. Conclusions. An important characteristic of the developed mathematical model of the generalized criterion is the possibility of obtaining a more accurate solution to the optimization problem under consideration with an uneven distribution of the heat load by means of a biased estimate of the temperature variance among consumers. The combined application of the methods of matrix generalization, pairwise comparison and vector optimization can improve the accuracy of the calculation when solving the optimization problem of choosing the best route of the thermal network.

An Improved Constrained Optimization Multi-Objective Genetic Algorithm and its Application in Engineering

2014 ◽  
Vol 962-965 ◽  
pp. 2903-2908
Author(s):  
Yun Lian Liu ◽  
Wen Li ◽  
Tie Bin Wu ◽  
Yun Cheng ◽  
Tao Yun Zhou ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Constrained Optimization ◽  
Optimization Problem ◽  
Optimization Problems ◽  
Crossover Operator ◽  
Multi Objective Optimization ◽  
Constrained Optimization Problem ◽  
Great Ability ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm

An improved multi-objective genetic algorithm is proposed to solve constrained optimization problems. The constrained optimization problem is converted into a multi-objective optimization problem. In the evolution process, our algorithm is based on multi-objective technique, where the population is divided into dominated and non-dominated subpopulation. Arithmetic crossover operator is utilized for the randomly selected individuals from dominated and non-dominated subpopulation, respectively. The crossover operator can lead gradually the individuals to the extreme point and improve the local searching ability. Diversity mutation operator is introduced for non-dominated subpopulation. Through testing the performance of the proposed algorithm on 3 benchmark functions and 1 engineering optimization problems, and comparing with other meta-heuristics, the result of simulation shows that the proposed algorithm has great ability of global search. Keywords: multi-objective optimization;genetic algorithm;constrained optimization problem;engineering application

Cognitive Radio Decision Engine Based on Multi-Objective Genetic Algorithm

2011 ◽  
Vol 48-49 ◽  
pp. 314-317
Author(s):  
Di Wu ◽  
Sheng Yao Yang ◽  
J.C. Liu
Keyword(s):  
Genetic Algorithm ◽  
Cognitive Radio ◽  
Performance Optimization ◽  
Optimization Problem ◽  
Simulation Analysis ◽  
Multi Objective Optimization ◽  
Weighting Method ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Decision Engine

The performance optimization of cognitive radio is a multi-objective optimization problem. Existing genetic algorithms are difficult to assign the weight of each objective when the linear weighting method is used to simplify the multi-objective optimization problem into a single objective optimization problem. In this paper, we propose a new cognitive decision engine algorithm using multi-objective genetic algorithm with population adaptation. A multicarrier system is used for simulation analysis, and experimental results show that the proposed algorithm is effective and meets the real-time requirement.

Application of Optimal Control Theory to the Synthesis of High-Speed Cam-Follower Systems. Part 1: Optimality Criterion

1983 ◽  
Vol 105 (3) ◽  
pp. 576-584 ◽  
Author(s):  
M. Chew ◽  
F. Freudenstein ◽  
R. W. Longman
Keyword(s):  
Optimal Control ◽  
Control Theory ◽  
Dynamic Response ◽  
Optimal Control Theory ◽  
High Speed ◽  
Integrated Approach ◽  
Optimization Criterion ◽  
Design Stage ◽  
Trade Offs ◽  
Cam Follower

The synthesis of the parameters governing the dynamic response of high-speed cam-follower systems ideally involves an integrated approach capable of carrying out the tradeoffs necessary to achieve optimum dynamic response in the design stage. These trade-offs involve a balance between the system characteristics at the output and at the cam-follower interface. In this investigation optimal-control theory has been demonstrated to be a useful tool in developing such a tradeoff. Part 1 describes the development of an optimization criterion while Part 2 describes the application of optimal-control theory to the evaluation of system parameters satisfying the optimization criterion.

Sign in / Sign up

Export Citation Format

Share Document