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 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.

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.

DNA Fragment Assembly Using Multi-Objective Genetic Algorithms

2014 ◽  
Vol 5 (3) ◽  
pp. 84-108 ◽  
Author(s):  
Manisha Rathee ◽  
T. V. Vijay Kumar
Keyword(s):  
Optimization Problem ◽  
Nsga Ii ◽  
Fragment Assembly ◽  
Assembly Algorithm ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm ◽  
Dna Fragment ◽  
The Right ◽  
Dna Fragment Assembly ◽  
Single Objective

DNA Fragment Assembly Problem (FAP) is concerned with the reconstruction of the target DNA, using the several hundreds (or thousands) of sequenced fragments, by identifying the right order and orientation of each fragment in the layout. Several algorithms have been proposed for solving FAP. Most of these have solely dwelt on the single objective of maximizing the sum of the overlaps between adjacent fragments in order to optimize the fragment layout. This paper aims to formulate this FAP as a bi-objective optimization problem, with the two objectives being the maximization of the overlap between the adjacent fragments and the minimization of the overlap between the distant fragments. Moreover, since there is greater desirability for having lesser number of contigs, FAP becomes a tri-objective optimization problem where the minimization of the number of contigs becomes the additional objective. These problems were solved using the multi-objective genetic algorithm NSGA-II. The experimental results show that the NSGA-II-based Bi-Objective Fragment Assembly Algorithm (BOFAA) and the Tri-Objective Fragment Assembly Algorithm (TOFAA) are able to produce better quality layouts than those generated by the GA-based Single Objective Fragment Assembly Algorithm (SOFAA). Further, the layouts produced by TOFAA are also comparatively better than those produced using BOFAA.

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.

Concurrent Engineering Design of Sheet Stamping by Using an Inverse FE Approach

1997 ◽  
Author(s):  
Shiyong Yang ◽  
Kikuo Nezu
Keyword(s):  
Finite Element ◽  
Concurrent Engineering ◽  
Process Simulation ◽  
Three Dimensional ◽  
Sheet Forming ◽  
Design Stage ◽  
Forming Process ◽  
Element Analysis ◽  
Preliminary Design Stage ◽  
Product And Process

Abstract An inverse finite element (FE) algorithm is proposed for sheet forming process simulation. With the inverse finite element analysis (FEA) program developed, a new method for concurrent engineering (CE) design for sheet metal forming product and process is proposed. After the product geometry is defined by using parametric patches, the input models for process simulation can be created without the necessity to define the initial blank and the geometry of tools, thus simplifying the design process and facilitating the designer to look into the formability and quality of the product being designed at preliminary design stage. With resort to a commercially available software, P3/PATRAN, arbitrarily three-dimensional product can be designed for manufacturability for sheet forming process by following the procedures given.

A Spectral Optimization Algorithm for Multi-Objective Prototype Selection

1995 ◽  
Author(s):  
Andy Dong ◽  
Alice M. Agogino
Keyword(s):  
Optimization Algorithm ◽  
Parametric Design ◽  
Selection Process ◽  
Objective Evaluation ◽  
Design Synthesis ◽  
Multi Objective ◽  
Trade Offs ◽  
Spectral Optimization ◽  
The Right ◽  
Selection Of

Abstract In design synthesis, engineering prototypes make an ideal representation medium for preliminary designs. Unlike parametric design wherein a pre-specified design is parametrically varied, design synthesis demands artistic creativity and engineering experience to transform the previously known components, relationships and designs into a new form. The process compels the designer to ascertain which prototypes will, in some sense, best satisfy the design task. The challenge in this assignment lies in selecting the “right” design prototype. This selection process typically entails an objective evaluation of different designs that perform the same functions or have similar intended behavior and comparing trade-offs between alternate designs. This paper introduces a multi-objective spectral optimization algorithm for the selection of design prototypes based upon their functional representations. The optimization algorithm returns an index of rank, scoring the functional similarity of the proposed design to the goal design. Two illustrative examples apply the algorithm to the selection of a heat fin and beam.

Comparison of Numerical Methods for Determining Torsion Stiffness of Automotive Chassis

2011 ◽  
Author(s):  
Steven Tebby ◽  
Ebrahim Esmailzadeh ◽  
Ahmad Barari
Keyword(s):  
Finite Element Analysis ◽  
Analytical Approach ◽  
Torsional Stiffness ◽  
Design Stage ◽  
Element Analysis ◽  
Detailed Design ◽  
Vertical Displacements ◽  
Comparison Of The Results ◽  
Torsion Stiffness

The torsion stiffness of an automotive chassis can be determined using an analytical approach based purely on geometry, using an experimental method, or alternatively by employing a Finite Element Analysis (FEA) process. These three methods are suitable at different design stages and combined together could prove to be practical methods of determining the torsion stiffness of a chassis. This paper describes and compares two distinct FEA processes to determine the torsion stiffness of an automotive chassis during the detailed design stage. The first process iteratively applies forces to the model and records displacements, while the second process gradually applies vertical displacements in place of force to determine the torsional stiffness threshold. Each method is explained and supported with a case study to provide a basis of comparison of the results.

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