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Showing papers in "International Journal of Design Engineering in 2009"


Journal ArticleDOI
TL;DR: In this article, the authors suggest that sustainable design within a perspective of precaution can complement dominant preventive methods of decision-making used for ecodesign, and show how a precautionary approach can be used with the logic of sufficiency to complement the traditional preventive approaches based on efficiency for establishing/assessing sustainable solutions.
Abstract: This paper suggests that sustainable design within a perspective of precaution can complement dominant preventive methods of decision-making used for ecodesign. More specifically, it will show how a precautionary approach can be used with the logic of sufficiency to complement the traditional preventive approaches based on the logic of efficiency for establishing/assessing sustainable solutions. As a consequence precaution may allow designers to develop new areas of insight. Evidence suggests that environmental gains from technical improvements in product efficiency have historically been outweighed by an overall increase in consumption - rebound effects, where efficiency largely depends on technical innovations. Sufficiency relies on individual behavioural changes as well as on social innovation, improved well-being out of fewer goods and services. So a sustainable future can be founded on both efficiency (based on a preventive approach) and sufficiency (based on a precautionary approach).

22 citations


Journal ArticleDOI
TL;DR: In this paper, a new global optimisation algorithm, biogeography based optimisation (BBO), for solving discrete optimisation of a gear train is presented, where the objective considered is minimisation of weight.
Abstract: In this paper, a new global optimisation algorithm, biogeography based optimisation (BBO), for solving discrete optimisation of a gear train is presented. The efficiency and ease of application of the proposed optimisation algorithm is demonstrated by solving a discrete optimisation problem of a four stage gear train from the literature. The objective considered is minimisation of weight. Eighty six inequality constraints are considered which include, bending fatigue strength, contact strength, contact ratio, pinion/gear size, housing size, pitch for gears and kinematic constraints. Twenty two discrete design variables are considered in the optimisation. Design modification is done to reduce the design variables which include two different designs with 18 and 14 design variables. The results of the proposed method are compared with the results obtained by using other optimisation methods such as genetic algorithm, particle swarm optimisation (PSO), and differential evolution (DE). The solution obtained by using BBO is superior to those obtained by using other optimisation techniques.

22 citations



Journal ArticleDOI
TL;DR: In this article, a case study methodology has been used to measure what are the main changes that a supply chain undergoes when an innovation is introduced, and the results show that deeper innovations results in increasing complexity of the supply side, i.e., the number of suppliers, the reciprocal dependency between client and supplier, the types of orders and the relationship with traditional suppliers.
Abstract: Supply chain managers redesign their supply chain as a response to the introduction of new products. In highly innovative contexts, this ability is critical to ensure the success of the innovations on the market. However, little is known about what supply chains areas are more impacted by innovation, and therefore what actions supply chain managers should take, and how new product developers should define project portfolio sustainable by the supply chain. This paper sheds light on this issue. A case study methodology has been used to measure what are the main changes that a supply chain undergoes when an innovation is introduced. The results show that deeper innovations results in increasing complexity of the supply side, i.e. the number of suppliers, the reciprocal dependency between client and supplier, the types of orders and the relationship with traditional suppliers, and of the distribution side, i.e. the number and types of distributors.

15 citations


Journal ArticleDOI
TL;DR: In this article, the authors used an artificial neural network (ANN) to establish manufacturing cost-tolerance models for various manufacturing processes, and continuous ant colony optimisation (CACO) algorithm was used to obtain optimum combination of tolerances for minimum manufacturing cost.
Abstract: The allocation of tolerances for the components of a mechanical assembly strongly influences manufacturing cost and functional performance. In order to get a reliable tolerances and costs, it is necessary to obtain manufacturing cost-tolerance models. Traditionally, these models are established by various curve-fitting techniques using empirical experimental data. Existing empirical models, however, have considerably large model fitting error, inconsistent modelling accuracy over the tolerance range of typical manufacturing processes. Using these mathematical models will introduce a considerably large error in optimal design of component tolerances. This work presented in this paper uses an artificial neural network (ANN), to overcome above limitations, for establishing manufacturing cost-tolerance models for various manufacturing processes. Having built the ANN cost-tolerance models, continuous ant colony optimisation (CACO) algorithm is used to obtain optimum combination of tolerances for minimum manufacturing cost. A typical tolerance design example is used to illustrate the effectiveness and reliability of the proposed approach.

15 citations


Journal ArticleDOI
TL;DR: In this paper, a product model comprising the main design parameters relating to environmental performance is proposed to enable design teams to organize various areas of improvement/innovation hierarchically as early as possible in the design stage such methodological supports would enable the team to identify the improvements or innovations which potentially present the highest rate of environmental improvement.
Abstract: This article corresponds to a lack of methodological supports in the literature which would enable design teams to organise various areas of improvement/innovation hierarchically as early as possible in the design stage Such methodological supports would enable the team to identify the improvements or innovations which potentially present the highest rate of environmental improvement The proposed solution consists of setting up a product model comprising the main design parameters relating to environmental performance A design of experiments sheds light on the contribution of each parameter to the global environmental performance (evaluated in this instance by the end-score of the EI99 method) Each experimental level also contains a level of technico-economic feasibility (and a level of attractiveness for the user The deliverable of this tool constitutes the evaluation of the rate of environmental improvement for each area of improvement This is supplemented by its level of technico-economic feasibility and level of user attractiveness With this information, the design team is better able to make choices corresponding to what seems most feasible for the company, most acceptable for the user and best for the environment

12 citations


Journal ArticleDOI
Abstract: In this paper, we present a methodology for simulation-based product design optimisation using an internal state variable (ISV) constitutive modelling approach that captures the microstructure-property relations in the material. By modelling the stochastic uncertainties in the material model and the loading conditions, the design optimisation problem is formulated and solved using the reliability-based design optimisation (RBDO) methodology. The application problem considers the design optimisation of an A356-T6 cast aluminium component under maximum stress and damage constraints. Alternative metamodelling techniques are used to develop appropriate surrogate models in lieu of direct coupling of non-linear static finite element analysis and numerical design optimisation. Probabilistic design constraints are modelled using the safety index approach with the solution of the nested optimisation problem facilitated with the help of analytical surrogate models. Comparison of the optimisation results reveals the importance of using an ISV-based constitutive model that is sensitive to the growth of damage in material. Moreover, the solution of the RBDO problem captures the effects of uncertainty on finding the minimum weight design for the cast component.

12 citations


Journal ArticleDOI
TL;DR: In this article, the authors validate the concordance of the results provided by the exergy and LCA approach, as LCA is a widely used approach even though the scientific reliability of LCA techniques has been questioned.
Abstract: Environmental evaluation analysis made at an early design stage is an important practical problem because existing approaches such as the LCA method require detailed information about the studied product or service. Consequently, to be efficient such a method requires a product or service located in an advanced development phase. An exergy method offers an appropriate solution for an environmental evaluation analysis at an early design stage. The theoretical model has been validated in previous journal articles. The goal of the present article is to validate the concordance of the results provided by the exergy and LCA approach, as LCA is a widely used approach even though the scientific reliability of LCA techniques has been questioned. This paper addresses the last phase of the validation of the exergy approach by comparing results of a case study analysed through both commercial LCA software and an exergy approach.

11 citations


Journal ArticleDOI
TL;DR: In this article, two propagation methods are presented and compared to define new robotised gearbox architectures, based on a fuzzy process and a matrix approach, and a sensitivity analysis is conducted.
Abstract: Concepts like product architecture and modularity have been introduced in order to limit the effects of technological change on complex product design. Researchers have highlighted that product architectures and design organisations (projects, teams?) are strongly interrelated. However, little research has analysed this relationship. System architects and design managers need a method that helps them to simulate the mapping of the product architecture onto the project organisation by propagating choices and then assessing alternatives. In this paper, two propagation methods are presented and compared. The first one is based on a fuzzy process, which is proposed by the authors. The second one is based on a matrix approach. Both are applied to define new robotised gearbox architectures. A sensitivity analysis is conducted. It is concluded that in new product development situations or in reengineering projects, system architects could use these methods in the early design stages to forecast the more appropriate design project organisation.

10 citations


Journal ArticleDOI
TL;DR: In this paper, the authors examine the limits of change prediction with existing tools, describe different patterns of change propagation and discuss the challenges in predicting their occurrence, and argue that the effectiveness of predictions can be improved by accounting for effects of organisational aspects of change when predicting propagation paths.
Abstract: Engineering changes can necessitate further changes to other components, which can cause severe delays to schedules and overstretch resources. Predicting the effects of a change effectively can be challenging, depending on the modelling framework and process adopted for interrogating a design. This paper examines the limits of change prediction with existing tools, describes different patterns of change propagation and discusses the challenges in predicting their occurrence. It argues that the effectiveness of predictions can be improved by accounting for effects of organisational aspects of change when predicting propagation paths.

10 citations


Journal ArticleDOI
TL;DR: In this article, a robust design method is proposed for maximising environmental and economic performance for the product life cycle, which is demonstrated through a simple example of laptop computers. But the effectiveness and feasibility of this method are limited.
Abstract: Product life cycle design has gained increasing interest in recent years due to growing concerns about environmental problems. In general, there exist significant uncertainties (e.g., operating conditions, user preference, post-consumer product collection rate, etc.) in the product life cycle, requiring a design method that is robust and tolerant against these uncertainties. To this end, this paper discusses design strategies for products and their life cycle to enhance total performance as a defence measure. Based on the discussion, a robust design method is proposed for maximising environmental and economic performance for the product life cycle. The effectiveness and feasibility of this method are demonstrated through a simple example of laptop computers.

Journal ArticleDOI
TL;DR: In this article, a new optimisation algorithm, harmony elements algorithm (HEA), for solving mechanical engineering design optimisation problems is presented, which is inspired by an ancient Chinese philosophy, called as theory of five elements.
Abstract: In this paper a new optimisation algorithm, harmony elements algorithm (HEA), for solving mechanical engineering design optimisation problems is presented. This algorithm is inspired by an ancient Chinese philosophy, called as theory of five elements. The basic harmony element algorithm proposed by Cui and Guo (2008) is modified in this paper to reduce the computational effort by dividing the population into equal parts and by incorporating the mutation operator. The efficiency and ease of application of the proposed optimisation algorithm is demonstrated by solving five different mechanical components design problems such as pressure vessel, tension/compression spring, Belleville spring, welded beam and gear train. The results of the proposed method are compared with the results given by other optimisation techniques such as genetic algorithm (GA), particle swarm optimisation (PSO), ant colony algorithm (ACA), Lagrangian multiplier approach and branch and bound approach. In all the cases, the solutions obtained using the proposed modified HEA are superior to those obtained by other optimisation techniques.

Journal ArticleDOI
TL;DR: In this article, a layered and jointed welded cantilever beam model has been considered for examining the vibration energy dissipation due to interfacial friction of jointed structures.
Abstract: Vibration and noise reduction are crucial in maintaining high performance level and prolonging the useful life of machinery, automobiles, aerodynamic and spacecraft structures. It is observed that damping is caused by energy dissipation due to micro-slip along frictional interfaces. In this paper, a layered and jointed welded cantilever beam model has been considered for examining the vibration energy dissipation due to interfacial friction of jointed structures. Experiments are performed on mild steel specimens with a number of layers under different initial conditions of vibration to validate the theory developed. It is found that the interface pressure distribution characteristics, number of contacting layers, amplitude and frequency of vibration, length and thickness of specimen govern the damping capacity of jointed layered structures with welded joints. These results can be positively exploited in the design of machine tools, aircrafts, spacecrafts, satellites, automobiles and missile systems effectively to maximise their damping capacity.

Journal ArticleDOI
TL;DR: It is proved that Bayesian theory could be used to reduce the number of required test points and so, the cost of new product development.
Abstract: Constraints on diesel engine emissions have increased dramatically over the past ten years. In this situation, design of experiments (DoE) are generally used to model the engine's exhaust emissions (EE) behaviour. The main drawback of parametric modelling is that, if the system evolves (e.g. new product development), then the model is no longer valid. Our proposition, focused on change management, is based on the Bayesian theory and presents two new algorithms. The aim of this paper is to outline a method for readjusting LOLIMOT models resulting from the DoE with as little data as possible, in order to optimise the EE of new engines. Two algorithms are presented: one use new data to readjust the model and the other, use both new data and expert judgement. We prove that Bayesian theory could be used to reduce the number of required test points and so, the cost of new product development.

Journal ArticleDOI
TL;DR: In this article, the authors used a clustering method for assembly and the introduction of a mathematical model, describing the fuzzy liaisons between the components, allow them to design the product for disassembly, service, recycling, upgrading and assembly.
Abstract: This paper focuses on non-destructive disassembly for mechanical products as part of environment friendly manufacturing. An original approach using a clustering method for assembly and the introduction of a mathematical model, describing the fuzzy liaisons between the components, allow us to design the product for disassembly, service, recycling, upgrading and assembly. They also facilitate the determination of the problems related to the automation of assembly and disassembly sequences generation. To do so, the modelling of functional liaisons between parts helps to distinguish a simple contact from an attachment and subsets from subassemblies. Liaisons between components are described by matrices of fuzzy half degrees of liaison. The virtual locking liaisons could be extracted automatically from a B-rep model of a mechanical product on CAD and attachment liaisons are deduced from a fuzzy evaluation of their strength and condition changes.

Journal ArticleDOI
TL;DR: In this paper, the effect of cone angle and length of the feed slot on the performance of externally pressurised conical air bearing with a feed slot was investigated to obtain the effect.
Abstract: Externally-pressurised conical air bearings can carry axial as well as radial loads. It is advantageous to develop conical bearing system because of its simple shape, easy fabrication, small space requirement and adjustment of clearances in the assembly. These bearings have been studied for orifice feeding of air which causes dispersion losses resulting in reduced load capacity. Feed slot configuration approximates to a line source and gives good distribution of fluid pressure and reduces the dispersion losses. Various characteristics like load capacities and stiffnesses of an externally pressurised conical air bearing with a feed slot are investigated in this paper. These characteristics are studied to obtain the effect of cone angle and length of the slot on the performance of these bearings.

Journal ArticleDOI
TL;DR: In this paper, the non-linear dynamics of a high speed unbalanced rotor supported on ball bearings is analyzed and the results show the appearance of instability and chaos in the dynamic response as the speed of unbalanced shaft is varied.
Abstract: In this paper, non-linear dynamics of a high speed unbalanced rotor supported on ball bearings is analysed. The approach presented here accounts for contacts between balls and inner/outer races. The non-linearity in the rotor bearing system has been considered mainly due to Hertzian contact, unbalanced shaft and radial internal clearance. In the formulation, the contacts between balls and inner/outer races are considered as non-linear springs and also used non-linear damping, which is developed by correlating the contact damping force with the equivalent contact stiffness and contact deformation rate. The results show the appearance of instability and chaos in the dynamic response as the speed of unbalanced shaft is varied. The appearance of the regions like periodic, sub-harmonic and chaotic behaviour is observed to be strongly sensitive to the speed of the rotating shaft. Techniques like Poincare maps and frequency spectra are used to elucidate and to illustrate the diversity of the system behaviour.

Journal ArticleDOI
TL;DR: In this paper, two new terminologies for inclusive design (design for independence and design for integration) have been proposed, which are more meaningful compared to the already exiting terminologies.
Abstract: The basic problems to stimulate the need for inclusive design are described. The key issues and approaches adopted by various groups, organisations, and researchers for solution of the basic problems are investigated. Two new terminologies for inclusive design (design for independence and design for integration) are proposed, which are more meaningful compared to the already exiting terminologies. A new and broad definition of inclusive design is also provided which gives emphasis on four important priorities of inclusive design, namely, flexibility, ergonomics, independence and integration. The important segments of a community responsible for playing their roles in the area of inclusive design are highlighted. The research trends and developments in the area of inclusive design and the various advantages inclusive design can offer are presented.

Journal ArticleDOI
TL;DR: In this article, three pre-recycling centers were visited and observed; two coffee machines were disassembled and examined; the procedures were intended to provide examples of the various difficulties currently encountered in a common disassembly process, so that such hindrances can be avoided with new products.
Abstract: Current manufactured products are not always designed to fulfil ecological requirements. Products should be easy to dismantle in order to separate all materials so they can be reused, recovered or recycled. In most products, however, the junctions utilised are tightly joined, making it difficult to disassemble them. In order to contribute to the designers' work in developing easily-to-disassembly products, three pre-recycling centres were visited and observed; two coffee machines were disassembled and examined. Both procedures were intended to provide examples of the various difficulties currently encountered in a common disassembly process, so that such hindrances can be avoided with new products. It was concluded that designers and engineers should do this type of study to learn about the most serious problems of existing products with respect to their disassembly processes and about how to correct them, as was observed in our experiments.

Journal ArticleDOI
TL;DR: In this article, a system integrated to conventional computer aided design (CAD) environment and its supporting design process is described, where the main idea consists in checking systematically the mutual influences between the part and mold CAD models.
Abstract: In the current context, efficient DFM relying on the ability to manage simultaneously the definitions of the shape, the material and the process, is crucial. The aim of this article is to illustrate, for plastic injection moulding, how to tackle such a situation. To reach our target, computer aided engineering systems should enable to manage the mutual links between the product properties and the product and process parameters. Such a system integrated to conventional computer aided design (CAD) environment and its supporting design process are detailed. The main idea consists in checking systematically the mutual influences between the part and mould CAD models. The design process has two main design sequences: the part driven one and the mould driven one. The proposed architecture is implemented into the commercial CAD environment PTC ProEngineer. The use of the computer system is illustrated on a real study case dealing.

Journal ArticleDOI
TL;DR: In this paper, a manufacturability and assembly analysis for the new construction of a rigid body feeder cable junction of an electric motor is presented especially for converter drives, where the design for manufacturing and assembly aspects are presented in detail.
Abstract: At present, typical motor junction boxes do not incorporate cable glands, which would provide good electrical performance in terms of electromagnetic compatibility and ease of use, especially regarding the grounding connection. In this paper, a manufacturability and assembly analysis for the new construction of a rigid body feeder cable junction of an electric motor is presented especially for converter drives. Design for manufacturing and assembly aspects are presented in detail. One of the novelty values of the paper is to estimate the manufacturability with respect to the product's performance. Further, assembling and mounting the cable gland should be made easy, and the need of various tools and installing stages should be eliminated. The new connector design makes mounting easy and installation stages are minimised. The electrical performance of the cable gland is also measured and verified in a real environment for glands constructed with steel and zinc coated steel.

Journal ArticleDOI
TL;DR: In this article, the authors proposed a method for integrated product analysis from the viewpoints of environmental burden and customer value, and verified the effectiveness of the proposed method is verified through its application.
Abstract: Environmental problems, such as global warming have become more serious in the last two decades. For environmental sustainability, the production and consumption of artefacts should be reduced. According to this background, many environmentally conscious products/services are available in the market. However, these products/services are not necessarily acceptable to customers at present. A possible reason for this is that few ecodesign methodologies and tools have been successfully used to effectively incorporate customer needs. Eco-products/services must be environmentally friendly as well as conform to the customer requirements. This paper proposes a method for integrated product analysis from the viewpoints of environmental burden and customer value. The effectiveness of the proposed method is verified through its application.

Journal ArticleDOI
TL;DR: In this article, the non-linear thermo-elastic response characteristics of laminated composite conical panels with temperature dependent material properties are studied employing finite element approach based on first-order shear deformation theory and field consistency principle.
Abstract: Non-linear thermo-elastic response characteristics of laminated composite conical panels with temperature dependent material properties are studied employing finite element approach based on first-order shear deformation theory and field consistency principle. The non-linear governing equations are solved using Newton-Raphson iterative technique coupled with the adaptive displacement control method to trace equilibrium path. Validation of the formulation for mechanical and thermal loading cases is carried out. Present study is carried out for thermal/thermo-mechanical loading with degradation of material properties. Parametric study is carried out to highlight the influence of semi-cone angle, length-to-radius ratio, radius-to-thickness ratio, and boundary conditions on the non-linear thermo-elastic response of laminated cylindrical and conical panels.

Journal ArticleDOI
TL;DR: A product-model able to represent microproducts during the design flow, taking into account their specificities and exceeding the limits of product representation in actual design tools is presented.
Abstract: Microproducts show specificities compared to macroproducts and their design processes differ. Nowadays, existing design tools manage microproduct specificities too late during the design process, only after the first product representation is available. This article presents a product-model able to represent microproducts during the design flow, taking into account their specificities and exceeding the limits of product representation in actual design tools. The genericity of this model is demonstrated by the instantiation of a micro electro mechanical system (MEMS) radio frequency (RF) switch.