A Computable Fastener Representation to Support Computer-Aided Configuration Design for the Life Cycle

1997 ◽  
Author(s):  
Brian Harper ◽  
Zahed Siddique ◽  
David Rosen
Keyword(s):  
Life Cycle ◽  
Degrees Of Freedom ◽  
Design Stage ◽  
Configuration Design ◽  
Assembly Model ◽  
Type Selection ◽  
Parametric Relationship ◽  
Integrate Analysis ◽  
Model Assemblies ◽  
Modeling Representation

Abstract Most of a product’s life-cycle characteristics are determined during the configuration design stage, when the product’s components are selected and arranged spatially and logically. One set of choices that determines many life-cycle characteristics is fastener type selection. In this paper, an assembly modeling representation is presented that supports changes in fastener types and fastening mechanisms while maintaining consistent degrees-of-freedom among fastened components. A fastening mechanism template and a corresponding instantiation algorithm have been developed for tensile-compressive fasteners. The template consists of four main elements: an assembly representation template, CSG tree fragments (to allow geometry construction), geometric constraint templates, and a parametric relationship template to integrate analysis equations into fastener models. Each particular fastener type is modeled by a specific template that is developed manually using the general template as a guide. The instantiation algorithm maps a particular fastening template onto an existing assembly model (assemblies, components, geometry, and mating relationships) in order to add fasteners to a product. A similar fastener substitution algorithm enables the replacement of one fastener type with another. The use of the algorithms is illustrated in the configuration design of an automotive center console. The paper concludes with a brief demonstration of how fastener selection affects life-cycle product characteristics.

Design of Modular Product Architectures in Discrete Design Spaces Subject to Life Cycle Issues

1996 ◽  
Author(s):  
David W. Rosen
Keyword(s):  
Life Cycle ◽  
Physical Structure ◽  
Discrete Mathematics ◽  
Design Stage ◽  
Configuration Design ◽  
Reasoning System ◽  
Modular Product ◽  
Discrete Structures ◽  
Design Requirements ◽  
A Company

Abstract A product’s architecture affects the ability of a company to customize, assemble, service, and recycle the product. Much of the flexibility to address these issues is locked into the product’s design during the configuration design stage when the architecture is determined. The concepts of modules and modularity are central to the description of an architecture, where a module is a set of components that share some characteristic. Modularity is a measure of the correspondence between the modules of a product from different viewpoints, such as functionality and physical structure. The purpose of this paper is to investigate formal foundations for configuration design. Since product architectures are discrete structures, discrete mathematics, including set theory and combinatorics, is used for the investigation. A Product Module Reasoning System (PMRS) is developed to reason about sets of product architectures, to translate design requirements into constraints on these sets, to compare architecture modules from different viewpoints, and to directly enumerate all feasible modules without generate-and-test or heuristic search approaches. The PMRS is described mathematically and applied to the design of architectures for a hand-held tape recorder. Life cycle requirements are used as design criteria.

Implications of Modularity on Product Design for the Life Cycle

1998 ◽  
Vol 120 (3) ◽  
pp. 483-490 ◽  
Author(s):  
P. J. Newcomb ◽  
B. Bras ◽  
D. W. Rosen
Keyword(s):  
Life Cycle ◽  
Product Design ◽  
Design Stage ◽  
Configuration Design ◽  
Large Role ◽  
Detailed Design ◽  
Normal Product ◽  
Center Console ◽  
Two Measures ◽  
Configuration Information

Growing concern for the environment has spurred interest in product Design for the Life Cycle (DFLC) which encompasses all aspects of a product’s life cycle from initial conceptual design, through normal product use, to the eventual disposal of the product. A product’s architecture, determined during the configuration design stage, plays a large role in determining its life cycle characteristics. In this paper, modularity of product architectures with respect to life cycle concerns, not just functionality and structure, is defined and applied in the analysis of architecture characteristics. An architecture decomposition algorithm from the literature is adopted for partitioning architectures into modules from each life cycle viewpoint. Two measures of modularity are proposed: one that measures module correspondence between several viewpoints, and another that measures coupling between modules. The algorithm and measures are applied to the analysis and redesign of an automotive center console. Results of applying the algorithm and measures accurately reflected our intuitive understanding of the original center console design and predicted the results of our redesign. Furthermore, these measures incorporate only configuration information of the product, hence, can be used before detailed design stages.

scholarly journals Implementation of dimensional management methodology and optimisation algorithms for pre-drilled hinge line interfaces of critical aero assemblies – A case study

2020 ◽  
pp. 095440542097810
Author(s):  
Konstantinos C Bacharoudis ◽  
David Bainbridge ◽  
Alison Turner ◽  
Atanas A Popov ◽  
Svetan M Ratchev
Keyword(s):  
Degrees Of Freedom ◽  
Engineering Problem ◽  
Hole Diameter ◽  
Design Stage ◽  
Assembly Process ◽  
Mechanical Assembly ◽  
Hinge Line ◽  
Management Procedure ◽  
Dimensional Management ◽  
Optimisation Algorithms

A dimensional management procedure is developed and implemented in this work to deal with the identification of the optimum hole diameter that needs to be pre-drilled in order to successfully join two subassemblies in a common hinge line interface when most of the degrees of freedom of each subassembly have already been constrained. Therefore, an appropriate measure is suggested that considers the assembly process and permits the application of optimisation algorithms for the identification of the optimum hole diameter. The complexity of the mechanical subassemblies requires advanced 3D tolerance analysis techniques to be implemented and the matrix method was adopted. The methodology was demonstrated for an industrial, aerospace engineering problem, that is, the assembly of the joined wing configuration of the RACER compound rotorcraft of AIRBUS Helicopter and the necessary tooling needed to build the assembly. The results indicated that hinge line interfaces can be pre-opened at a sufficiently large size and thus, accelerate the assembly process whilst the suggested methodology can be used as a decision-making tool at the design stage of this type of mechanical assembly.

Variable geometry wing-box: toward a robotic morphing wing.

2021 ◽  
Author(s):  
Amin Moosavian
Keyword(s):  
Degrees Of Freedom ◽  
Minimum Energy ◽  
Parallel Manipulators ◽  
Parallel Robots ◽  
Optimal Configuration ◽  
Configuration Design ◽  
Variable Geometry ◽  
Static Characteristics ◽  
Actuation Redundancy ◽  
Wing Box

The ability to vary the geometry of a wing to adapt to different flight conditions can significantly improve the performance of an aircraft. However, the realization of any morphing concept will typically be accompanied by major challenges. Specifically, the geometrical constraints that are imposed by the shape of the wing and the magnitude of the air and inertia loads make the usage of conventional mechanisms inefficient for morphing applications. Such restrictions have served as inspirations for the design of a modular morphing concept, referred to as the Variable Geometry Wing-box (VGW). The design for the VGW is based on a novel class of reconfigurable robots referred to as Parallel Robots with Enhanced Stiffness (PRES) which are presented in this dissertation. The underlying feature of these robots is the efficient exploitation of redundancies in parallel manipulators. There have been three categories identified in the literature to classify redundancies in parallel manipulators: 1) actuation redundancy, 2) kinematic redundancy, and 3) sensor redundancy. A fourth category is introduced here, referred to as 4) static redundancy. The latter entails several advantages traditionally associated only with actuation redundancy, most significant of which is enhanced stiffness and static characteristics, without any form of actuation redundancy. Additionally, the PRES uses the available redundancies to 1) control more Degrees of Freedom (DOFs) than there are actuators in the system, that is, under-actuate, and 2) provide multiple degrees of fault tolerance. Although the majority of the presented work has been tailored to accommodate the VGW, it can be applied to any comparable system, where enhanced stiffness or static characteristics may be desired without actuation redundancy. In addition to the kinematic and the kinetostatic analyses of the PRES, which are developed and presented in this dissertation along with several case-studies, an optimal motion control algorithm for minimum energy actuation is proposed. Furthermore, the optimal configuration design for the VGW is studied. The optimal configuration design problem is posed in two parts: 1) the optimal limb configuration, and 2) the optimal topological configuration. The former seeks the optimal design of the kinematic joints and links, while the latter seeks the minimal compliance solution to their placement within the design space. In addition to the static and kinematic criteria required for reconfigurability, practical design considerations such as fail-safe requirements and design for minimal aeroelastic impact have been included as constraints in the optimization process. The effectiveness of the proposed design, analysis, and optimization is demonstrated through simulation and a multi-module reconfigurable prototype.

ANALYSIS OF LANDSLIDE PROCESSES ON THE ROADS OF KHAKASSIA BEFORE THE BRIDGES OVER THE YENISEI RIVER FROM THE PERSPECTIVE OF ALL STAGES OF THE LIFE CYCLE OF STRUCTURES

2020 ◽  
Author(s):  
Олег Закирович Халимов
Keyword(s):  
Life Cycle ◽  
Design Stage ◽  
Yenisei River ◽  
The Road ◽  
Road Section ◽  
Hydrogeological Conditions ◽  
First Case ◽  
Landslide Processes ◽  
The Yenisei River ◽  
Hydrogeological Studies

В статье проанализированы трудности в процессе строительства автомобильной дороги от Братского моста через Енисей в сторону Абакана, связанные с отсутствием учета на стадии проектирования осложнившихся гидрогеологических условий, влияющих на опускание моста и дороги. Оползневые процессы, созданные искусственно при сооружении выемки дна автомобильной дороги от Братского моста более 40 лет развиваются на участке дороги Абакан-Подсинее перед железным и автодорожным мостом через Енисей. Как и в первом случае на стадии проектирования не выполнены гидро-геологические исследования. The article analyzes the difficulties in the process of construction of the highway from the Bratsk bridge over the Yenisei river to Abakan, associated with not taking into account the complicated hydrogeological conditions at the design stage, associated with the lowering of the bridge and road. Landslide processes created artificially during the construction of the dredging of the road bottom from the Bratsk bridge have been developing for more than 40 years on the Abakan-Podsinee road section in front of the railway and road bridge over the Yenisei. As in the first case, hydrogeological studies were not performed at the design stage.

Applications of Mating Conditions in Assembly Sequence Planning Task

1998 ◽  
Author(s):  
Pongsak Dulyapraphant ◽  
Tulga Ozsoy
Keyword(s):  
Degrees Of Freedom ◽  
Tolerance Analysis ◽  
Assembly Sequence Planning ◽  
Assembly Model ◽  
Assembly Sequence ◽  
Kinematics Analysis ◽  
Sequence Planning ◽  
Planning Task ◽  
Intuitive Interface ◽  
Mating Conditions

Abstract Because of their intuitive interface, mating conditions have been prevalently used in assembly modelling. Besides their use for modelling purposes, other type of information, such as spatial relationships between parts and local degrees of freedom, can be directly derived from mating conditions. This information in turn can be used in various engineering analysis applications, such as kinematics analysis or automatic tolerance chain generation for tolerance analysis. In this paper, application of mating conditions in an assembly sequence-planning task is investigated. The proposed approach mainly engages the mating information represented in the CAD assembly model to automatically generate sequence plans based on the minimization of the number of assembly directions.

Investigation on the Robustness of Rotor/Stator Contact Interactions with Respect to Small Mistuning

2021 ◽  
Author(s):  
Florence Nyssen ◽  
Alain Batailly
Keyword(s):  
Degrees Of Freedom ◽  
Design Stage ◽  
Contact Interactions ◽  
Reduced Basis ◽  
Amplification Factors ◽  
Bladed Disk ◽  
Nonlinear Amplification ◽  
Rotor Stator Interaction ◽  
Bending Modes ◽  
The Impact

Abstract In this work, the impact of small mistuning on rotor/stator contact interactions is investigated. First, a detailed study of a rotor/stator interaction between the first bending modes and the second engine order is presented in the tuned case. Then, a numerical investigation on the effect of mistuning on the studied rotor/stator contact interaction is carried out. In particular, a stochastic analysis is performed to evaluate the robustness of the interaction with respect to the mistuning level. Simulations are conducted using a reduced order model (ROM) of an industrial bladed disk that combines both physical degrees of freedom (along blades tip for contact treatment) and modal coordinates. Mistuning is introduced in the tuned ROM by means of a modified version of the component mode mistuning method that allows to keep physical degrees of freedom within the reduced basis. Nonlinear amplification factors, i.e. the amplification factors in the context of contact nonlinearities, are compared with their linear counterparts, the latter are computed using a linear forcing on each blade using a two nodal diameters traveling wave excitation on the mistuned and the tuned bladed disk. The comparison between the linear and nonlinear amplification factor for each sample highlights that no correlation exists between a mistuning pattern leading to high amplifications in a linear context or when contact nonlinearities are taken into account. Therefore, dedicated analyses on the effect of mistuning should be undertaken with contact nonlinearities considerations at the design stage especially if intentional mistuning is considered.

scholarly journals Analog Circuit Design Automation Tool Using Genetic Algorithms

1970 ◽  
Vol 1 (1) ◽  
Author(s):  
Y. M. A. Khalifa ◽  
D. H. Horrocks
Keyword(s):  
Genetic Algorithms ◽  
Circuit Design ◽  
Analog Circuits ◽  
Computer Aided Design ◽  
Degrees Of Freedom ◽  
Analog Circuit ◽  
Search Space ◽  
Design Stage ◽  
Specific Frequency ◽  
Aided Design

An investigation into the application of Genetic Algorithms (GA) for the design of electronic analog circuits is presented in this paper. In this paper an investigation of the use of genetic algorithms into the problem of analog circuits design is presented. In a single design stage, circuits are produced that satisfy specific frequency response specifications using circuit structures that are unrestricted and with component values that are chosen from a set of preferred values. The extra degrees of freedom resulting from unbounded circuit structures create a huge search space. It is shown in this paper that Genetic Algorithms can be successfully used to search this space. The application chosen is a LC all pass ladder filter circuit design.Key Words: Computer-Aided Design, Analog Circuits, Artificial Intelligence.

Whole Life/Life Cycle Costing During the Design Stage of a Construction Project

2020 ◽  
Vol 9 (2) ◽  
pp. 66-87
Author(s):  
Daniel Clarke-Hagan ◽  
Michael Curran ◽  
John Spillane ◽  
Mary-Catherine Greene
Keyword(s):  
Life Cycle ◽  
Qualitative Methodology ◽  
Construction Project ◽  
Life Cycle Costing ◽  
Design Stage ◽  
Life Cycle Costs ◽  
Mind Mapping ◽  
Advantages And Disadvantages ◽  
Mapping Software ◽  
Whole Life Costing

The calculations of life cycle costs (LCC) and whole life costs (WLC) are important tools in the life cycle of a project. The aim of this research is to examine life cycle costing, whole life costing, and the possible advantages and disadvantages to their introduction and use. A qualitative methodology encompassing an in-depth literature review, interviews, and qualitative analysis using mind mapping software, this research is important as it can add to the industry's understanding of the design process. It highlights reasons for the success or failure of a construction project, in terms of sustainability at the design stage. Results indicate that the researched topics had many advantages but also had inherent disadvantages. It is found that the potential advantages outweighed disadvantages, but uptake within industry is still slow and that better promotion and their benefits to sustainability, the environment, society, and the industry are required.

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