Multi-criteria Decision Analysis for Supporting the Selection of Engineering Materials in Product Design

Ali Jahan, Kevin L Edwards, Marjan Bahraminasab

• Publisher: Butterworth-Heinemann
• Year: 2016
• ISBN:
  9780081005415
• Edition: 2
• Topic: Tecnología e ingeniería
• Subtopic: Ciencias de los materiales

Multi-criteria Decision Analysis for Supporting the Selection of Engineering Materials in Product Design, Second Edition, provides readers with tactics they can use to optimally select materials to satisfy complex design problems when they are faced with the vast range of materials available.

Current approaches to materials selection range from the use of intuition and experience, to more formalized computer-based methods, such as electronic databases with search engines to facilitate the materials selection process. Recently, multi-criteria decision-making (MCDM) methods have been applied to materials selection, demonstrating significant capability for tackling complex design problems.

This book describes the rapidly growing field of MCDM and its application to materials selection. It aids readers in producing successful designs by improving the decision-making process. This new edition updates and expands previous key topics, including new chapters on materials selection in the context of design problem-solving and multiple objective decision-making, also presenting a significant amount of additional case studies that will aid in the learning process.

• Describes the advantages of Quality Function Deployment (QFD) in the materials selection process through different case studies
• Presents a methodology for multi-objective material design optimization that employs Design of Experiments coupled with Finite Element Analysis
• Supplements existing quantitative methods of materials selection by allowing simultaneous consideration of design attributes, component configurations, and types of material
• Provides a case study for simultaneous materials selection and geometrical optimization processes

1

The importance of decision support in materials selection

Abstract

The selection of materials at all stages of the product design process requires effective decision-making. The nature of the problem is both complex and varying from having to consider a large number of available materials and vague information in the early design stages to a small number of acceptable materials and detailed information in the later design stages. The inclusion of hybrid materials and newly developed materials although offering the potential of enhanced performance can further exacerbate the problem. To fully satisfy the design requirements, decision-making support is essential to correctly select the most appropriate design, materials, and manufacturing processes in the design and development of new engineering products.

Keywords

Decision-making; product design; materials selection; materials costs; materials substitution; materials databases

Learning Aims

The overall aim of this chapter is to gain an overview of decision-making involved in materials selection. After carefully studying this chapter you should be able to understand:

• the critical stages of the materials selection process associated with designing new products

• the significance of supporting effective decision-making in materials selection

• the notion of relationship between design, materials, and manufacturing processes

• the challenges of selecting materials to satisfy conflicting design requirements

• the economic considerations that should be taken into account when selecting materials

• the approaches that can be used for substituting either conventional or new materials in product design

• the role of materials in the creation of sustainable products.

1.1 Introduction to materials selection

The selection of the most appropriate material for a particular purpose is a crucial function in the design and development of products. Materials influence product function, customer satisfaction, production systems, product life cycle, who is going to use or produce it, usability, product personality, operating environment, and costs in a complex way.

Materials selection can be carried out to either choose alternative materials for changes to the design of an existing product in order to reduce say cost or weight, meet new legal requirements, overcome failure occurrence, or satisfy different market demands, or it can be used to choose materials for the design of a completely new product. The materials selection process is similar for existing and new products although the starting point and information requirements may differ. The interdisciplinary effort required in most cases is nontrivial and the engineering designer not only requires detailed, accessible, and timely information about materials’ properties but also knowledge of multi-criteria decision-making (MCDM).

This book describes the main principles and strategic application of MCDM techniques to support engineering product designers compare the performance of established materials, hybrid materials, and new materials, when selecting the most appropriate materials for new product design.

1.2 Background and justification for formalized materials selection

There are an enormous number of materials available, each with a range of different properties and behaviors. New materials are also constantly being developed with enhanced properties, expanding the list of options available to the engineering designer. The materials’ properties, and combination of properties in the form of performance indices, can be mapped on to materials’ selection charts, pioneered by Ashby (2013). In the charts, the materials naturally cluster into the different classes of metals, polymers, elastomers, glasses, and ceramics. However, only parts of the charts are populated with materials, leaving holes or gaps in the selection space. New materials with enhanced properties can reduce the size of or fill gaps within clusters, or expand the boundary of clusters, or the gaps between clusters can potentially be filled or “bridged” with hybrid or multi-materials such as composite materials as shown schematically in Fig. 1.1.

Figure 1.1 Hybrid materials combine the properties of two (or more) monolithic materials.

The historical evolution in the use and development of materials reflects the progress of the interdisciplinary science from the early civilizations until today (Brechet and Embury, 2013). The strategy with respect to materials usage started in the Stone Age by using the available materials such as stone and wood and then later copper and bronze (Bronze Age) and iron (Iron Age). Afterwards, the strategy gradually focused on the optimization of specific classes of materials. This lead to the development of tools for comparing and selecting materials from different classes of materials already optimized in terms of their engineering potential. Today, the emphasis has shifted more towards the consideration of economical aspects and environmental impact. This has created a tendency towards the development of materials using design strategies with an increased importance of modeling and multi-functionality of materials (Brechet and Embury, 2013). However, there is still a lot of fundamental materials research being conducted without careful consideration being given to its practical application (Edwards, 2011). This not only justifies the need for the greater use of materials selection tools but also the importance of supporting decision-making to better understand and manage the multi-objective product design process.

1.3 Decision-making and concession in product design

Introducing a completely new product or improving an existing product involves a complex chain of interdependent activities including design, analysis, materials selection, and consideration of manufacturing processes, and all depend on MCDM. As well as influencing material properties, process selection is a prerequisite to manufacturing equipment selection. However, materials selection used to be only a minor part of the design process (Chiner, 1988) and therefore has not received the same level of research and development as other fields of design. The selection of suitable materials for a specific purpose though is a difficult, time-consuming, and expensive process because of the large number of available materials with complex relationships and various selection parameters. As a consequence, approximations are made with materials frequently being chosen by “trial-and-error” or simply on the basis of what has been successfully used in the past. This approach though can lead to compromise and unpredictable outcomes, possible premature failures, and limits the ability to achieve an optimal choice of materials.

The stage reached in the design process is important because the nearer a product is to manufacture the greater is the cost of making any design change (Charles et al., 1997). It has been estimated that the relative cost of a design change after manufacture is 10,000 times more than at the conceptual stage of design (Charles et al., 1997). Therefore, it is worth making decisions carefully and spending enough time early on in the design process using systematic selection techniques. This makes it easier to manage the “trade-offs” between design, materials, shape, and manufacturing processes and lead to an optimum design solution.

To satisfy customer requirements, manufacturing organizations must be continually aware of product costs, reliability, durability and recyclability, and market trends. These attributes should be addressed strategically by manufacturers through a continuous process of improvement in an ongoing effort to improve their products (Jahan and Edwards, 2013). This will only be fully achieved through optimum decision-making about design, materials, and manufacturing processes (Chakladar et al., 2009; Blanch et al., 2011) and provides the opportunity for sustainable and profitable growth. To support this process, MCDM techniques have developed dramatically in both theory and practice, especially in the fields of design and manufacturing, with growing interest in their application to materials selection.

1.4 The position of materials selection in the engineering design process—from concept to detail stages

The successful design of an engineering component is integral to satisfying the functional and customer specified requirements for the overall product of which it forms a part, utilizing material properties and capabilities of suitable manufacturing processes (Zarandi et al., 2011). The behavior of a material used to create a component will be affected by component geometry, external forces, properties of stock material before processing, and the effect of manufacturing (or fabrication) method (Farag, 2008a). The evaluation of the typically large number of design solutions (altering the size, shape, and mass of the component) and suitability of an even larger number of different materials rapidly becomes too complicated to be intuitive. This highlights the value of being able to use MCDM to support decision-making in the engineering design process. Although experimental-based selection of a material, eg, testing, prototyping, etc., for a specific design solution is the most accurate, it quickly becomes unreasonable due to the time required and the high costs of...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface to the 2nd edition
• From the Preface to the 1st edition
• About the authors
• 1. The importance of decision support in materials selection
• 2. Materials selection in the context of design problem-solving
• 3. Screening of materials
• 4. Multi-criteria decision-making for materials selection
• 5. Multi-attribute decision-making for ranking of candidate materials
• 6. Multiple objective decision-making for material and geometry design
• 7. Case studies of materials selection and design
• 8. Future developments
• Index