Strategic Thinking: Matching Material to Design 2/24/2019 2/24/2019 Strategic Thinking: Matching Material to Design © 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION. 1

Selection of materials and processes runs parallel with design process

New idea or working principle New material may suggest a new product New product may require a new material Market need is put in terms of a need statement – “Devices is required to perform task X” Product specification – detailed plan for new design

Three design stages between identifying the market need and developing a product specification Information about materials is needed at each stage, but at very different levels of breadth and precision

Improving a current design while keeping the working principle on which it operates and many of its components Why? Product recall Poor value for money Inadequate profit margin Stay ahead of competition

Three Concepts: Removal by axial traction (a) Need Statement: A device is required to allow access to wine in a corked bottle with convenience, at modest cost, and without contaminating the wine Three Concepts: Removal by axial traction (a) Removal by torsional traction (b) Push it out from below (c)

Detailed drawings of the lever mechanism of (b) shown – part dimensioned and the surface finish - material and manufacturing route defined – (d) show sketches based on concept of removal by axial tractions – shows the layout, mechanism and scale

The selection of a material begins with a catalog of all materials, which is narrowed by screening out those that fail to meet the design requirements Concept stage Designer requires only approximate property values, but for widest range of material Embodiment stage Data needed for a subset of materials, but at a higher level of detail and precision Detail stage Even higher level of detail and precision, but for few materials

To make a shape, a material is subjected to processes that, together, are called manufacture Process selection is influenced by the material – its formability, its machinability, its weldability, its capacity for heat treatment, etc. Process selection is influenced by the requirement for shape – the process determines the shape, size, precision, and greatly contributes to the cost

Two-Way Interactions: Specification of shape restricts the choice of material and process Specification of process limits the materials you can use and the shape they can take

Select the best match between the attribute profiles of the materials and processes and those required by the design 4 Step Process Translation Screening Ranking Documentation

This is accomplished by identifying the following: Converting the design requirements into a prescription for selecting a material This is accomplished by identifying the following: Function What does the component do? Constraints What non-negotiable conditions must the material meet? Objectives What aspects of performance must be maximised or minimised Free Variables What parameters of the problem is the designer free to change?

Constraint Objective Common Constraints Common Objectives Essential condition that must be met, usually expressed as a limit on a material or process attribute Objective Quantity for which an extreme value is sought Common Constraints Common Objectives Meet a target value of: Minimise: Stiffness Cost Strength Mass Fracture toughness Volume Thermal conductivity Impact on Environment Electrical resistivity Heat loss Magnetic permanence Optical transparency Maximise: Energy storage Heat flow

Example The figure shows the level for a corkscrew. It is loaded in bending. It must be used without deflecting to a noticeable amount which means it must have a high modulus E. It must not bend permanently which means a high yield strength σy. And it must not snap off, which means it must have enough fracture toughness K1c. Finally, it must not corrode in wine or water. Given the above, the lever should be as cheap as possible. Formulate the translation.

Answer: Translation for corkscrew lever Function Lever (beam loaded in bending) Constraint type Constraints Stiff enough Functional Strong enough Some toughness Resist corrosion in wine and water Length L given Geometric Objective Minimise cost Free Variable Choice of material Choice of cross-section area